AU2017272328A1 - A circuit arrangement and a switchboard with the circuit arrangement - Google Patents

Abstract

A circuit arrangement of a switchboard for connecting a power supply including an active wire, a neutral wire and an earth wire to a socket including an active pin, a neutral pin and an earth pin, the circuit arrangement comprising a first switch having a first contact terminal and a first associated contact terminal, the first contact terminal of the first switch being configured to electrically connect to the active wire of the power supply in use, a first terminal block electrically connected to the first associated contact terminal of the first switch, a second switch having a second contact terminal and a second associated contact terminal, the second contact terminal of the second switch being configured to electrically connect to the first terminal block, and the second associated contact terminal of the second switch being electrically connected to the active pin of the socket. eee3320 - 342 32431 -4 334 302 f314 316 30 308 310 312 313 315 301a 301c 308a 310a 312a 314a 316a 301b

Description

A CIRCUIT ARRANGEMENT AND A SWITCHBOARD WITH THE CIRCUIT

ARRANGEMENT

Cross-reference [01] The entire contents of Australian patent applications No. 2017208323 and No. 2017232107 are incorporated herein by reference.

Technical Field [02] The present invention relates to a switchboard and in particular, although not exclusively, this invention relates to a circuit arrangement for a switchboard and a switchboard with the circuit arrangement. The circuit arrangement allows convenient and safe connection of a further switchboard to the switchboard without affecting other switchboards.

Background [03] At a construction or renovation site, electrical tools (for example, an electric drill) are used to perform a construction or renovation task. Electricity energy that powers the electric tools is supplied through a switchboard, which is normally installed at the site temporarily. Multiple switchboards installed at different levels or a same level of a building can be connected together to power a number of electrical tools distributed over a large area. The electric tools include for example, drills, cutting machines, welding equipment and similar electrical equipment.

[04] Figure 1 illustrates an existing circuit arrangement 100 of a switchboard. The switchboard normally includes an enclosure (not shown) to enclose the circuit arrangement 100. The switchboard may also include a stand (not shown) that supports the enclosure.

[05] When in use, terminal blocks (i.e., active links) 114 of the circuit arrangement 100 are connected to active wires 102 of a power supply (not shown). The power supply can be a previous switchboard that supplies electricity to the switchboard or a general power switch at the construction site. Further, a terminal block (i.e., earth link) 118 of the circuit arrangement 100 is connected to an earth wire 106 of the power supply, and a terminal block (i.e., neutral link) 116 of the circuit arrangement 100 is connected to a neutral wire 104 of the power supply. This way, this switchboard is able to carry electric potentials (i.e., voltages), particularly, on the terminal blocks 114 and active wires 101 of the circuit arrangement 100. Additionally, the circuit arrangement 100 also includes main switches 120 that can switch on and off electricity supply to sockets 124, and circuit protection devices 122 (such as Residual Current Devices (RCD), Circuit Breaker (CB), and Residual Current Circuit Breakers with Overcurrent Protection (RCBO)) connected between the main switches 120 and the sockets 124 of various ratings, such as 10A or 15A or 32A, etc.

[06] It is common that a further switchboard (not shown) needs to be connected to the switchboard as the construction work progresses, for example, a new level is to be built or one more switchboard is needed to cover a larger area on the same level, that is, the switchboard is effectively used as a power supply for the further switchboard. Therefore, active wires 108 need to be comiected between the terminal blocks (i.e., active links) 144 of the circuit arrangement 100 and the active links of the further switchboard. Further, a neutral wire 110 needs to be connected between the terminal block (i.e., neutral link) 116 of the circuit arrangement 100 and the neutral link of the further switchboard, and an earth wire 112 needs to be connected between the terminal block (i.e., earth link) 118 of the circuit arrangement 100 and the earth link of the switchboard. However, as required by safety requirements, the terminal blocks or the active links 114 of the circuit arrangement 100 are not allowed to carry power when the further switchboard is being connected to the switchboard. Therefore, the general power switch of the construction site has to be switched off in order for a worker to safely connect the further switchboard to the switchboard. As a result, all the switchboards at the construction site will lose power, which is safe but causes inconvenience as all the electric tools at the construction site have to stop working. This causes additional costs due to downtime of the all the switchboards and the electric tools.

[07] Accordingly, there is a need for an improved circuit arrangement of a switchboard and a switchboard with the improved circuit arrangement that do not suffer from above mentioned deficiencies.

[08] Throughout this specification, unless the context requires otherwise, the words “comprise”, “comprises” and “comprising” will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements.

[09] Any one of the terms: “including” or “which includes” or “that includes” as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others.

[010J Any discussion of the background art throughout the specification should in no way be considered as an admission that such background art is prior art nor that such background art is widely known or forms part of the common general knowledge in the field in Australia or worldwide.

Summary [011] There is provided a circuit arrangement of a switchboard for connecting a power supply including an active wire, a neutral wire and an earth wire to a socket including an active pin, a neutral pin and an earth pin. The circuit arrangement comprises: a first switch having a first contact terminal and a first associated contact terminal, the first contact terminal of the first switch being configured to electrically connect to the active wire of the power supply in use; a first terminal block electrically connected to the first associated contact terminal of the first switch; a second switch having a second contact terminal and a second associated contact terminal, the second contact terminal of the second switch being configured to electrically connect to the first terminal block, and the second associated contact terminal of the second switch being electrically connected to the active pin of the socket; a second tenninal block configured to electrically connect to the neutral wire of the power supply in use and to the neutral pin of the socket; and a third terminal block configured to electrically connect to the earth wire of the power supply in use and to the earth pin of the socket.

[012] It is an advantage of the present invention that, the first switch is installed between the active wire of the power supply and the first terminal block, which allows the switchboard (particularly, the first terminal block) to be isolated from the power supply if the first switch is switched off. This way, when connecting a further switchboard to the switchboard, the general switch at the construction site does not need to be switched off. Instead, only the first switch of the switchboard is switched off to disconnect electricity supply to the first terminal block in order to meet safety requirements. On the other hand, as the general switch is not switched off, other switchboards are not affected. This is highly desirable from safety point of view as well as for preventing any downtime of the other switchboar ds.

[013] The circuit arrangement may further comprise a circuit protection device between the second associated contact terminal of the second switch and the active pin of the socket, the circuit protection device electrically connecting the second associated contact terminal of the second switch to the active pin of the socket.

[014] The circuit protection device may comprise a residual circuit breaker with overcurrent protection (RCBO).

[015] The second terminal block may be electrically connected to the neutral pin of the socket via the RCBO.

[016] The first terminal block may comprise a first connection mechanism connected to a first conductive wire that is connected to the first associated contact terminal of the first switch, a second connection mechanism connected to a second conductive wire that is connected to the second contact terminal of the second switch, and a third connection mechanism configured to connect to a third conductive wire that is connected to the first contact terminal of the first switch of a further switchboard.

[017] There is provided a circuit arrangement of a switchboard for connecting a power supply including a first active wire, a second active wire, a third active wire, a neutral wire and an earth wire to a socket including a first active pin, a second active pin, a third active pin, a neutral pin and an earth pin. The circuit arrangement comprises: a first switch having a first contact terminal and a first associated contact terminal, the first contact terminal of the first switch being configured to electrically connect to the first active wire of the power supply in use; a second switch having a second contact terminal and a second associated contact terminal, the second contact terminal of the second switch being configured to electrically connect to the second active wire of the power supply in use; a third switch having a third contact terminal and a third associated contact terminal, the third contact terminal of the third switch being configured to electrically connect to the third active wire of the power supply in use; a first terminal block electrically connected to the first associated contact terminal of the first switch; a second terminal block electrically connected to the second associated contact terminal of the second switch; a third terminal block electrically connected to the third associated contact terminal of the third switch; a fourth switch having a fourth contact terminal and a fourth associated contact terminal, the fourth contact terminal of the fourth switch being configured to electrically connect to the first tenninal block, and the fourth associated contact terminal of the fourth switch being electrically connected to the first active pin of the socket; a fifth switch having a fifth contact terminal and a fifth associated contact terminal, the fifth contact terminal of the fifth switch being configured to electrically connect to the second terminal block, and the fifth associated contact terminal of the fifth switch being electrically connected to the second active pin of the socket; a sixth switch having a sixth contact terminal and a sixth associated contact terminal, the sixth contact terminal of the sixth switch being configured to electrically connect to the third terminal block, and the sixth associated contact terminal of the sixth switch being electrically connected to the third active pin of the socket; a fourth terminal block configured to electrically connect to the neutral wire of the power supply in use and to the neutral pin of the socket; and a fifth terminal block configured to electrically connect to the earth wire of the power supply in use and to the earth pin of the socket.

[018] The circuit arrangement may further comprise a first circuit protection device between the fourth associated contact terminal of the fourth switch and the first active pin of the socket, the first circuit protection device electrically connecting the fourth associated contact terminal of the fourth switch to the first active pin of the socket; a second circuit protection device between the fifth associated contact terminal of the fifth switch and the second active pin of the socket, the second circuit protection device electrically connecting the fifth associated contact terminal of the fifth switch to the second active pin of the socket; and a third circuit protection device between the sixth associated contact terminal of the sixth switch and the third active pin of the socket, the third circuit protection device electrically connecting the sixth associated contact terminal of the sixth switch to the third active pin of the socket. 1019] The first circuit protection device may comprise a first circuit breaker (CB) and a first residual current device (RCD), the second circuit protection device may comprise a second CB and a second RCD, and the third circuit protection device may comprise a third CB and a third RCD.

[020] The circuit arrangement may further comprise a fourth RCD between the fourth terminal block and the neutral pin of the socket, the fourth RCD electrically connecting the fourth terminal block to the neutral pin of the socket.

[021] There is provided a switchboard, comprising: a circuit arrangement of any one of claims 1 to 9; and an enclosure configured to carry the circuit arrangement, the circuit arrangement being secured to enclosure, the enclosure comprising: a back panel having a first side edge, a second side edge, a third side edge and a fourth side edge; a first side panel extending from the first side edge of the back panel; a second side panel extending from the second side edge of the back panel; a third side panel extending from the third side edge of the back panel; a fourth side panel extending from the fourth side edge of the back panel and forming a front edge, the fourth side panel being adjacent to the first side panel and the second side panel; an engagement member having a first part and a second part, the first part of the engagement member being securely fixed to the fourth side panel, wherein the second part is configured to be pivotable relative to the first part and further configured to slide relative to the first part along a direction of the front edge of the fourth side panel to allow engagement with and disengagement from the first part along the direction of the front edge of the fourth side panel; and a front panel securely fixed to the second part of the engagement member.

[022] The fourth side panel may be configured to be horizontal when in use.

[023] The fourth side panel may be configured to be vertical when in use.

[024] The enclosure may further comprise a movement limiter detachably connected to the fourth side panel, the movement limiter being configured to limit the sliding of the second part of the engagement member relative to the first part of the engagement member in order to disable the disengagement of the second part from the first part. 1025] The second part of the engagement member may include an elongate pin and the first part of the engagement member may include an elongate hollow member configured to slidely and pivotably receive the elongate pin therein.

[026] The first part of the engagement member may include an elongate pin and the second part of the engagement member may include an elongate hollow member configured to slidely and pivotably receive the elongate pin therein.

[027] The movement limiter may be a bolt and the fourth side panel may include a hole with a thread to detachably connect the bolt to the fourth side panel via the thread.

[028] The hole may be located at a position where if the bolt is screwed into the fourth side panel, the bolt disables the disengagement of the second part of the engagement member from the first part of the engagement member.

[029] The enclosure may further comprise a support base secured to the back panel, the support base having a first section of a first height and a second section of a second height and being configured to allow electronic devices of different heights to be installed thereon.

[030] At least one of the first side panel and the second side panel may include a further opening, the further opening being sized to fit a three-phase socket.

[031] The switchboard may further comprise a stand that is connected to the enclosure to support the enclosure, the stand comprising: a first support arm to securely and detachably connect to the enclosure; a second support arm to securely and detachably connect to the enclosure, each of the first and the second support arms having a first end and a second end; a first beam to detachably connect the first end of the first support arm and the first end of the second support arm; a second beam to detachably connect the first support arm and the second support arm a first support foot to detachably connect to the second end of the first support arm; a second support foot to detachably connect to the second end of the second support arm, wherein the first support foot and the second support foot are configured to keep the first support arm and the second support arm in an upright positon when in use.

[032] The stand may further comprise: a cable holding assembly, the cable holding assembly comprising: a first support bar; and a first cable holding means that extends from the first support bar to hold a cable; and a first connection means configured to adjustably connect the first support bar to the first support arm.

[033] The first cable holding means may be a U-shaped bar such that the cable can be held by the U-shaped bar.

[034] The stand may further comprise: a lamp installation assembly, the lamp installation assembly comprising: a second support bar; and a lamp installation means that extends from the second support bar for installation of a lamp thereon; and a second connection means configured to adjustably connect the second support bar to the second support arm.

[035] The lamp installation means may be a straight bar with at least one hole such that the lamp can be installed on the straight bar via at least one bolt through the at least one hole.

[036] The second beam may further include a cable winding means, the cable winding means extending from a first position on the second beam and ends at a second position on the second beam such that the cable can be wound around the cable winding means between the first position and the second position.

Brief Description of Drawings [037] At least one example of the present invention will be described with reference to the accompanying drawings, in which: [038] Figure 1 illustrates a circuit arrangement of a switchboard in prior art; [039] Figure 2A illustrates a circuit arrangement of a switchboard for a power supply having a single phase in accordance with an embodiment of the present invention; [040] Figure 2B illustrates an example of a first terminal block in accordance with an embodiment of the present invention; [041] Figure 2C illustrates a perspective view of the first terminal block of Figure 2B; [042] Figure 3A illustrates a circuit arrangement of a switchboard for a power supply having three phases in accordance with an embodiment of the present invention; [043] Figure 3B illustrates an arrangement of isolator switches in accordance with an embodiment of the present invention; [044] Figure 3C illustrates an arrangement of main switches in accordance with an embodiment of the present invention; [045] Figure 4 illustrates a circuit arrangement of a switchboard for a power supply having three phases in accordance with an embodiment of the present invention; [046] Figure 5 illustrates a circuit arrangement of a switchboard for a power supply having three phases in accordance with another embodiment of the present invention; [047] Figure 6A illustrates a switchboard with a circuit arrangement in accordance with the present invention; [048] Figure 6B illustrates an example of an engagement member in accordance with an embodiment of the present invention; [049] Figure 6C illustrates another example of the engagement member in accordance with another embodiment of the present invention; [050] Figure 6D illustrates an example of an enclosure for carrying the circuit arrangement in accordance with the present invention; [051] Figure 7 illustrates a switchboard with a circuit arrangement in accordance with the present disclosure; [052] Figure 8 illustrates a perspective view of a first support arm and a second support arm in accordance with an embodiment of the invention; [053] Figure 9 illustrates a partial perspective view of a stand in accordance with an embodiment of the invention; [054] Figure 10 illustrates a partial perspective view of the stand in accordance with an embodiment of the invention; and [055] Figure 11 illustrates a partial perspective view of the stand in accordance with an embodiment of the invention.

[056] It should be noted in the accompanying drawings and description below that like or the same reference numerals in different drawings denote the same or similar elements.

Description of Embodiments [057] Figure 2A illustrates a circuit arrangement 200 of a switchboard for a power supply having a single phase in accordance with an embodiment of the present invention. The power supply includes an active wire 202, a neutral wire 216 and an earth wire 220. For illustration purpose, only the active wire 202, the neutral wire 216 and the earth wire 220 of the power supply are shown in Figure 2A, and other parts of the power supply are not shown in Figure 2A. As described above, the power supply may be a previous switchboard or a general switch at a construction site. The circuit arrangement 200 is used to connect the power supply to a socket 234 of the circuit arrangement 200. The socket 234 may be rated at different currents, for example, 10A, 15 A, 32 A or even lower or higher, depending upon the application of the socket 234, such as current rating of an electrical tool that needs to be operated. The socket 234 includes an active pin 236 for electrically connecting with the active wire 202, a neutral pin 238 for electrically connecting with the neutral wire 216 and an earth pin 240 for electrically connecting with the earth wire 220.

[058] The circuit arrangement 200 includes a first switch 204 having a first pair of contact terminals 206, 208. The contact terminal 208 is associated with the contact terminal 206 in the sense that the contact terminal 208 is able to be electrically connected to or disconnected from the contact terminal 206. That is, if the first switch 204 is switch on, the contact terminal 208 is electrically connected to the contact terminal 206, while if the first switch 204 is switched off, the contact terminal 208 is electrically disconnected from the contact terminal 206. 'T he first switch 204 is also referred to as isolator switch hereinafter, also known as a disconnector or a disconnect switch in electrical engineering. The isolator switches are used to disconnect or isolate a part of a circuit arrangement for service and maintenance purposes. The isolator switches may be manually or automatically operated. The first contact terminal 206 of the isolator switch 204 is configured to electrically connect to the active wire 202 of the power supply in use. Generally, for making connections with a switch, such as the isolator-switch 204 and other switches used in the present invention, screws and/or spring loaded retainers may be used to tightly hold the wires or conductors at contact terminals of the switch. Additionally, a pair of male and female plugs may also be used for making quicker connections, wherein one of the male or the female plug is provided at a contact terminal of a switch and the other one is provided at an end of the wire. Further a first tenninal block 210 (i.e., active link) is electrically connected to the first associated contact terminal 208 of the isolator switch 204, for example, via a first conductive wire 209. In that manner, the supply of power to the first terminal block 210 via the active wire 202 can be disconnected by switching off the isolator switch 204. 1059] The circuit arrangement 200 includes a second switch 226. The second switch 226 is also referred to as main switch hereinafter. The main switch 226 controls the supply of power to the socket 234 without affecting the first terminal block 210. That is, if the socket 234 needs to be checked by a worker or it is necessary to have the supply of power to the socket 234 disconnected, the worker can switch off the main switch 226, while the supply of power to the first terminal block 210 is not affected. The main switch 226 includes a second contact terminal 228 and a second associated contact terminal 230. The second contact terminal 228 of the main switch 226 is configured to electrically connect to the first terminal block 210, for example, via a second conductive wire 221, and the second associated contact terminal 230 of the main switch 226 is electrically connected to the active pin 236 of the socket 234. Further, the circuit arrangement 200 includes a second terminal block 214 (i.e., neutral link). The second terminal block 214 electrically connects to the neutral wire 216 of the power supply in use. The second terminal block 214 also electrically connects to the neutral pin 238 of the socket 234. The circuit arrangement 200 further includes a third terminal block 222 (i.e., earth link). The third terminal block 222 electrically connects to the earth wire 220 of the power supply in use and also to the earth pin 240 of the socket 234.

[060] A terminal block in the present disclosure refers to a block of conductive material, for example, metal, which is used to make electrical connections between multiple conductive wires or electrical devices in a circuit. Figure 2B illustrates an example of the first terminal block 210 in accordance with an embodiment of the present invention.

[061] As shown in Fig. 2B, the first terminal block 210 includes a first connection mechanism 2102. The first connection mechanism 2102 is connected to the first conductive wire 209 that is connected to the first associated contact terminal 208 of the isolator switch 204. As a result, the first terminal block 210 is electrically connected to the associated contact terminal 208 of the isolator switch 204. The first terminal block 210 also includes a second connection mechanism 2103. The second connection mechanism 2103 is connected to the second conductive wire 221. As shown in Figure 2A, the second conductive wire 221 is connected to the second contact terminal 228 of the main switch 226. Therefore, the first terminal block 210 is electrically connected to the main switch 226. The first terminal block 210 further includes a third connection mechanism 2104. When connecting a further switchboard to the switchboard, the third connection mechanism 2104 is connected to a third conductive wire 212, which is the active wire of the further switchboard. The third conductive wire 212 is connected to the first contact terminal of the first switch of the further switchboard (not shown).

[062] Figure 2C is a perspective view of the first terminal block 210. As shown in Figure 2C, each of the connection mechanisms 2102, 2103 and 2104 includes a pair of screws. The pair of screws secure the respective conductive wire in a hole formed in the first terminal block 210. The connection mechanisms 2102, 2103 are arranged in a way that makes it convenient to connect the respective wire. Particularly, the connection mechanisms 2102, 2103 are arranged at the top of the first terminal block 210, while the connection mechanism 2104 is arranged at the bottom of the first terminal block 210.

[063] As shown in Figure 2A, the further active wire 212 for the further switchboard extends from the first terminal block 210. Similarly, a further neutral wire 218 for the further switchboard extends from the second terminal block 214 and a further earth wire 224 for the further switchboard extends from the third terminal block 222. As the isolator switch 204 is installed between the first terminal block 210 and the active wire 202, the first terminal block 210 can be isolated from the active wire 202 by switching off the isolator switch 204. This way, the supply of power to all other switchboards need not to be interrupted while connecting the further switchboard to the switchboard. This is highly desirable from safety point of view as well as for preventing any downtime of the other switchboards.

[064] It is also desirable to ensure that there is enough protection provided in the circuit arrangement 200 of the switchboard to protect against conditions such as leakage currents and overcurrents due to short circuit, spikes and surges. Therefore, the circuit arrangement 200 includes a circuit protection device 232 between the second associated contact terminal 230 of the main switch 226 and the active pin 236 of the socket 234. The circuit protection device 232 electrically connects the second associated contact terminal 230 of the main switch 226 to the active pin 236 of the socket 234. In various embodiments the circuit protection device 232 includes a Residual Circuit Breaker with Overcurrent Protection (RCBO). Also, the second terminal block 214 is electrically connected to the neutral pin 238 of the socket 234 via the RCBO. The earth pin 240 of the socket 234 may be directly electrically connected with the third terminal block 222.

[065] A skilled addressee would appreciate that the RCBO combines functions of a Residual Current Device (RCD) and a Miniature Circuit Breaker (MCB) in one device. The RCD part allows it to counter supply imbalances due to current leakage, such as when a person is experiencing an electrical shock. The MCB part protects during overcurrent situations, such as during spikes or surges in the circuit arrangement. In various jurisdictions, the RCBO is also known as a Ground Fault Circuit Interrupter (GFCI). Also, a commonly known device in various jurisdictions, called an Arc Fault Circuit Interrupter (AFCI) is also envisaged to be within the scope of the present invention. In various other embodiments, a standalone RCD may be used as the circuit protection device 232.

[066] In use, before the further switchboard is connected to the switchboard, particularly, the circuit arrangement 200, the electrical connection between the active wire 202 and the first terminal block (i.e., active link) 210 is disconnected by switching off the first switch 204. This isolates the first terminal block 210 from the power supply. Therefore, a worker is able to safely connect the third conductive wire 212 between the first terminal block 210 and the first contact terminal of the first switch of the further switchboard. Similarly, the further neutral wire 218 is connected to a second terminal block (i.e., neutral link) of the further switchboard and the further earth wire 224 is connected to a third terminal block (i.e., earth link) of the further switchboard. After making the above mentioned connections, the electrical connection between the first terminal block 210 and the active wire 202 is restored by switching the isolator switch 204 on. This way, the further switchboard is powered by the switchboard without affecting the other switchboards as the general switch at the construction site does not needed to be switched off.

[067] It will be appreciated by a skilled addressee that the implementation of the present invention is not limited to the power supply with the single phase only. The circuit arrangement 200 may be modified for a poly-phase power supply and an exemplary implementation of the invention for a power supply with three phases is discussed below.

[068] Figure 3A illustrates a circuit arrangement 300 of a switchboard for a power supply having three phases. The circuit arrangement 300 has a three phase five-pin socket 324 (also referred to as ‘the socket 324’). A typical current rating of the three phase five-pin socket 324 is 32A. The power supply includes a first active wire 301a, a second active wire 301b, a third active wire 301c, a neutral wire 313 and an earth wire 315. The circuit arrangement 300 connects the power supply to the socket 324 having a first active pin 326, a second active pin 328, a third active pin 330, a neutral pin 332 and an earth pin 334. In this scenario, instead of one, three isolator switches, i.e., a first switch 302, a second switch 304 and a third switch 306 are included in the circuit arrange 300 corresponding to the first active wire 301a, the second active wire 301b and the third active wire 301c respectively. The first switch 302, the second switch 304 and the third switch 306 are also referred to as first isolator switch 302, second isolator switch 304 and third isolator switch 306, respectively.

[069] Figure 3B illustrates the arrangement of three isolator switches 302, 304, 306 connected to active wires 301a, 301b, 301c, in Figure 3A. The first isolator switch 302 includes a first contact terminal 3022 and a first associated contact terminal 3024. The first contact terminal 3022 is associated with the first associated contact terminal 3024 in the sense that the first contact terminal 3022 is able to be electrically connected to or disconnected from the first associated contact terminal 3024. That is, if the first isolator switch 302 is switch on, the first contact terminal 3022 is electrically connected to the first associated contact terminal 3024, while if the first isolator switch 302 is switched off, the first contact terminal 3022 is electrically disconnected from the first associated contact terminal 3024. The second isolator switch 304 includes a second contact terminal 3042 and a second associated contact terminal 3044. The third isolator switch 306 includes a third contact terminal 3062 and a third associated contact terminal 3064. The first contact terminal 3022 of the first switch 302 is configured to electrically connect to the first active wire 301a of the power supply in use. The second contact terminal 3042 of the second switch 304 is configured to electrically connect to the second active wire 301b of the power supply in use. The third contact terminal 3062 of the third switch 306 is configured to electrically connect to the third active wire 301c of the power supply in use.

[070] Further, the circuit arrangement 300 includes a first terminal block 308, a second terminal block 310 and a third terminal block 312. The first terminal block 308 is electrically connected to the first associated contact terminal 3024 of the first isolator switch 302. The second terminal block 310 is electrically connected to the second associated contact terminal 3044 of the second isolator switch 304. Also, the third terminal block 312 is electrically connected to the third associated contact terminal 3064 of the third isolator switch 306. Further, as shown in Figure 3A, the circuit arrangement 300 comprises a fourth switch 318, a fifth switch 320 and a sixth switch 322, also referred to as first main switch 318, second main switch 320, third main switch 322, to electrically connect with the terminal blocks 308, 310 312, respectively. The main switches 318, 320, 322 control the supply of power to the socket 324 without affecting the terminal blocks 308, 310, 312. That is, if the socket 324 needs to be checked by a worker or it is necessary to have the supply of power to the socket 234 disconnected, the worker can switch off the main switches 318, 320 322, while the supply of power to the terminal blocks 308, 310, 312 is not affected.

[071] Figure 3C illustrates the arrangement of the fourth switch 318, the fifth switch 320, and the sixth switch 322 connected to the terminal blocks 308, 310, 312 in Figure 3A. The fourth switch 318 has a fourth contact terminal 3182 and a fourth associated contact terminal 3184. The fourth contact terminal 3182 of the fourth switch 318 is configured to electrically connect to the first terminal block 308, and the fourth associated contact terminal 3184 of the fourth switch 318 is electrically connected to the first active pin 326 of the socket 324. The fifth switch 320 has a fifth contact terminal 3202 and a fifth associated contact terminal 3204. The fifth contact terminal 3202 of the fifth switch 320 is configured to electrically connect to the second tenninal block 310, and the fifth associated contact terminal 3204 of the fifth switch 320 is electrically connected to the second active pin 328 of the socket 324. The sixth switch 322 has a sixth contact terminal 3222 and a sixth associated contact terminal 3224. The sixth contact terminal 3222 of the sixth switch 322 is configured to electrically connect to the third terminal block 312, and the sixth associated contact terminal 3224 of the sixth switch 322 is electrically connected to the third active pin 330 of the socket 324.

[072] Terminal blocks 314 and 316 have also been included in the circuit arrangement 300 to electrically connect with the neutral wire 313 and the earth wire 315. The fourth terminal block 314 (also referred to as neutral link 314) is configured to electrically connect to the neutral wire 313 of the power supply and to the neutral pin 332 of the socket 324. The fifth terminal block 316 (also referred to as earth link 316) is configured to electrically connect to the earth wire 315 of the power supply and to the earth pin 334 of the socket 324.

[073] In the circuit arrangement 300, the first isolator switch 302 is installed between the first terminal block 308 and the first active wire 301a, the second isolator switch 304 is installed between the second terminal block 310 and the second active wire 301b, and the third isolator switch 306 is installed between the third terminal block 312 and the third active wire 301c. This allows the terminal blocks 308, 310, 312 to be isolated from active wires 301a, 301b, 301c if the isolator switches 302, 304, 306 are switched off. When connecting a further switchboard to the switchboard in order to use the switchboard as a power supply for the further switchboard, the worker switches off the isolator switchers 302, 304, 306 to disconnect the supply of electricity to the terminal blocks 308, 310, 312 without interrupting other switchboards. Then the worker connects active wires 308a, 310a, 312a of the further switchboard to the terminal blocks 308, 310, 312, respectively. The worker also connects a neutral wire 314a of the further switchboard to the neutral link 314, and an earth wire 316a of the further switchboard to the earth link 316. This way, the operation of all other switchboards need not to be interrupted while connecting the further switchboard to the switchboard. Such a circuit arrangement 300 enables the worker to safely connect the further switchboard to the switchboard without affecting other switchboards. This is highly desirable from safety point of view as well as for preventing downtime of the other switchboards.

[074] The circuit arrangement 300 for the power supply with three phases also needs installation of safety devices for compliance with safety regulations. Therefore, additional safety devices are provided in the circuit arrangement 300.

[075] The circuit arrangement 300 further includes a first circuit protection device 336 between the fourth associated contact terminal 3184 of the fourth switch 318 and the first active pin 326 of the socket 324. In that manner, the first circuit protection device 336 electrically connects the fourth associated contact terminal 3184 to the first active pin 326 of the socket 324. In one embodiment of the invention, the first circuit protection device 336 includes a first circuit breaker (CB) and a first residual current device (RCD). Similarly, a second circuit protection device 338 is provided between the fifth associated contact terminal 3204 of the fifth switch 320 and the second active pin 328 of the socket 324. In that manner, the second circuit protection device 338 electrically connects the fifth associated contact terminal 3204 to the second active pin 328 of the socket 324. In one embodiment of the invention, the second circuit protection device 338 includes a second circuit breaker (CB) and a second residual current device (RCD). Also, a third circuit protection device 340 is provided between the sixth associated contact terminal 3224 of the sixth switch 322 and the third active pin 330 of the socket 324. In that manner, the third circuit protection device 340 electrically connects the sixth associated contact terminal 3224 to the third active pin 330 of the socket 324. In one embodiment of the invention, the third circuit protection device 340 includes a third circuit breaker (CB) and a third residual current device (RCD).

[076] Normally, in a power supply with multiple phases (for example: three phases), a neutral conductor carries current proportional to the active conductors. Only, in cases where the three phases are balanced, the neutral conductor may carry very little current. In either case, it is intended that the neutral conductor should not be carrying any residual currents. This is essential for safety of the personnel operating the switchboard as well as for longevity of the circuit arrangement. Therefore, a fourth RCD 342 is provided between the fourth terminal block (i.e., neutral link) 314 and the neutral pin 332 of the socket 324. In that manner, the fourth RCD 342 electrically connects the fourth terminal block 314 to the neutral pin of the socket 324.

[077] Figure 4 illustrates a circuit arrangement 400 of the switchboard for a power supply having three phases in accordance with an embodiment of the present invention. The discussion regarding Figure 4 is quite similar to discussion of Figures 3A to 3C. However, the five pin three phase socket 324 is replaced with three groups of single phase sockets, i.e. a first socket group 344, a second socket group 346 and a third socket group 348. As shown in Figure 4, the first socket group 344 includes four single phase sockets, the second socket group 346 includes four single phase sockets, and the third socket group 348 includes one single phase socket. The first circuit protection device 336 electrically connects the fourth associated contact terminal 3184 to active pins of the first socket group 344, the second circuit protection device 338 electrically connects the fifth associated contact terminal 3204 to active pins of the second socket group 346 and the third circuit protection device 340 electrically connects the sixth associated contact terminal 3224 to an active pin of the third socket group 348. Also, the first circuit protection device 336 electrically connects the fourth terminal block (i.e., the neutral link) 314 to neutral pins of the first socket group 344, the second circuit protection device 338 electrically connects the fourth terminal block 314 to neutral pins of the second socket group 346 and the third circuit protection device 340 electrically connects the fourth terminal block 314 to a neutral pin of the third group 348.

[078] Figure 5 illustrates a circuit arrangement 500 of the switchboard for a power supply having three phases in accordance with another embodiment of the present invention. Figure 5 is a combination of Figure 3A and Figure 4. Figure 5 includes the five pin three phase socket 324 and the first socket group 344, the second socket group 346 and the third socket group 348 of single phase sockets. The circuit arrangement 500 includes a number of circuit protection devices for making electrical connections.

[079] Figure 6A illustrates a switchboard 600 with a circuit arrangement in accordance with the present invention. The circuit arrangement can be any of the circuit arrangements described above. As an example, the circuit arrangement 500 shown in Figure 5 is used in the switchboard 600. The wires connecting the electronic devices of the circuit arrangement 500 are not shown for a clear view. As shown in Figure 6A, the switchboard 600 includes an enclosure 601 to carry or house the electronic devices of the circuit arrangement 500.

[080] The enclosure 601 comprises a back panel 602. The back panel 602 is typically a thin plate. The back panel 602 may include a plurality of holes 615 in order to fix the enclosure 601 to a wall or a stand (not shown in Figure 6A) that supports the enclosure 601. The back panel 602 includes a first side edge 604, a second side edge 606, a third side edge 608 and a fourth side edge 610 that define a periphery of the back panel 602. The enclosure 601 further includes a plurality of side panels extending from the edges of the back panel 602 respectively to define a wall. For example, the enclosure 601 further includes a first side panel 6042, a second side panel 6062, a third side panel 6082 and a fourth side panel 6102. As shown in Figure 6A, the first side panel 6042 extends from the first side edge 604 of the back panel 602. The second side panel 6062 extends from the second side edge 606 of the back panel 602. The third side panel 6082 extends from the third side edge 608 of the back panel 602. Also, the fourth side panel 6102 extends from the fourth side edge 610 of the back panel 602. Thus, the side panels 6042, 6062, 6082 and 6102 form a wall extending from the edges of the back panel 602.

[081] Moreover, the first side panel 6042 is located opposite to the second side panel 6062 and the third side panel 6082 is located opposite to the fourth side panel 6102. As shown in Figure 6A, the fourth side panel 6102 and the third panel 6082 are adjacent to the first side panel 6042 and the second side panel 6062. Also, the extension of the fourth side panel 6102 from the fourth side edge 610 fonns a front edge 612. Thus, the fourth side panel 6102 extends from the fourth side edge 610 at one end and forms the front edge 612 parallel to the fourth side edge 610 at another end.

[082] In accordance with an embodiment of the present invention, the enclosure 601 further comprises an engagement member 614. The engagement member 614 includes a first part 6142 and a second part 6144. The first part 6142 is configured to pivot relative to the second part 6144 and/or vice versa. Also, the second part 6144 is further configured to slide relative to the first part 6142 along a direction of the front edge 612 of the fourth side panel 6102. The second part 6144 slides along the direction of the front edge 612 of the fourth side panel 6102 to allow engagement with and disengagement from the first part 6142 along the direction of the front edge 612 of the fourth side panel 6102.

[083] Returning to Figure 6A, the enclosure 601 further comprises a front panel 616. The front panel 616 works as a cover of the enclosure 601 that enables or disables access to the electronic devices installed in the enclosure 601. In accordance with an embodiment of the present invention, the first part 6142 of the engagement member 614 is securely fixed to the fourth side panel 6102 and the front panel 616 is securely fixed to the second part 6144 of the engagement member 614. The first part 6142 and the second part 6144 are securely fixed to the fourth side panel 6102 and the front panel 616 respectively by for example welding, structural adhesive and rivets. It will be appreciated by a person skilled in the art that other joining means such as fastening and hot pressing may also be used.

[084] At least some electronic devices (for example, the isolator switches 302, 304, 306, the terminal blocks 308, 310, 312, etc.) of the circuit arrangement 500 are fixed to the back panel 602 mechanically inside the enclosure 601, while the five-pin three phase socket 324 is secured to the second side panel 6062 for easy access. As the front panel 616 is joined with the fourth side panel 6102 using the engagement member 614, the engagement member 614 allows the front panel 616 to pivot relative to the fourth side panel 6102. Thus, due to the pivoting of the front panel 616, the front panel 616 takes two positions, an open position and a closed position. At the open position, the electronic devices installed inside the enclosure 601 are accessible for use and conducting activities such as inspection and maintenance, whereas in the closed position, the front panel 616 covers the enclosure 601 and no access to the electronic devices inside the enclosure 601 is available.

[085] Figure 6B illustrates an example of the engagement member 614 in accordance with an embodiment of the present invention. As shown in Figure 6B, the first part 6142 of the engagement member 614 includes a first tab 6143 and an elongate hollow member 6146. Although the first tab 6143 and the elongate hollow member 6146 are shown in Figure 6B to be formed integrally, the first tab 6142 and the elongate hollow member 6146 can be separate parts that are mechanically connected together. The second part 6144 of the engagement member 614 includes a second tab 6145 and an elongate pin 6148. Similarly, although the second tab 6145 and the elongate pin 6148 are shown in Figure 6B to be formed integrally, the second tab 6145 and the elongate pin 6148 can be separate parts that are mechanically connected together. Also, the elongate hollow member 6146 of the first part 6142 is configured to slidely and pivotably receive the elongate pin 6148 of the second part 6144. Particularly, the elongate pin 6148 of the second part 6144 is able to slide into the elongate hollow member 6146 of the first part 6142 to engage the first part 6142 with second part 6144. The elongate pin 6148 is also able to slide out of the elongate hollow member 6146 to disengage the first part 6142 from the second part 6144. Further, due to the round outer surface of the elongate pin 6148 and the round inner surface of the elongate hollow member 6146, the elongate pin 6148 is able to pivot within the elongate hollow member 6146.

[086] Figure 6C illustrates another example of the engagement member 614 in accordance with another embodiment of the present invention. As shown in Figure 6C, the first part 6142 of the engagement member 614 includes the elongate pin 6148 and the second part 6144 of the engagement member 614 includes the elongate hollow member 6146. Further, the hollow member 6146 of the second part 6144 is configured to slidely and pivotably receive the elongate pin 6148 of the first part 6142, as described with reference to Figure 6B.

[087] Figure 6D illustrates an example of the enclosure 601 for carrying the circuit arrangement in accordance with the present invention. The enclosure 601 further comprises a movement limiter 622. The movement limiter 622 is detachably connected to the fourth side panel 6102. When the movement limiter 622 is connected to the fourth side panel 6102, the movement limiter 622 limits the sliding of the second part 6144 of the engagement member 614 relative to the first part 6142 of the engagement member 614 in order to disable the disengagement of the second part 6144 from the first part 6142. On the other hand, if the movement limiter 622 is removed from fourth side panel 6102 by for example a worker using a screwdriver, the second part 6144 (particularly, the elongate pin 6148) of the engagement member 614 can be slid out of the first part 6142 (particularly, the elongate hollow member 6146) of the engagement member 614. This way, the front panel 616 that is fixed to the second part 6144 of the engagement member 614 can be removed from the enclosure 601 even if the front panel 616 is in the closed position. Therefore, if the switchboard with the enclosure 601 is sandwiched between two other switchboards, which makes it hard if not impossible to place the front panel 616 at the open position, the front panel 616 can be removed in order for the worker to access the electronic devices installed in the enclosure 601. In one embodiment of the present invention, the movement limiter 622 is a bolt which is inserted into a hole 624 provided on the fourth side panel 6102. In one embodiment of the present invention, the hole 624 includes a thread to fasten the bolt into the hole 624. The bolt can be screwed into the hole 624 of the fourth side panel 6102 with a portion of the bolt projecting from the fourth side panel 6102. This portion of the bolt limits the sliding of the second part 6144 of the engagement member 614 relative to the first part 6142 of the engagement member 614. On the other hand, if the bolt is removed from the hole 624 by a screwdriver, the second part 6144 (particularly, the elongate pin 6148) of the engagement member 614 can be slid out of the first part 6142 (particularly, the elongate hollow member 6146) of the engagement member 614. This allows the removal of the front panel 616 from the enclosure 601.

[088] In the example shown in Figure 6A, the fourth side panel 6102 is the horizontal top panel when in use, and thus the front panel 616 horizontally slides along the direction of the front edge 612 of the fourth side panel 6102. Therefore, the movement limiter 622 that is detachably connected to the fourth side panel 6102 limits the horizontal sliding of the front panel 616. In another embodiment, the fourth side panel 6102 is a vertical side panel when in use, and the front panel 616 vertically slides along the direction of the front edge 612 of the fourth side panel 6102, Therefore, the movement limiter 622 that is detachably connected to the fourth side panel 6102 limits the vertical sliding of the front panel 616.

[089] Additionally, the hole 624 is located on the fourth side panel 6102 at a position where if the bolt is screwed into the fourth side panel 6102 by a worker using a screwdriver, the bolt disables the disengagement of the second part 6144 of the engagement member 614 from the first part 6142 of the engagement member 614. That is, the hole 622 is located near the engagement member 614 such that the bolt limits the sliding movement of the first part 6142 with respect to the second part 6144 of the engagement member 614. Thus, the bolt is provided to prevent the detachment of the two parts that are first part 6142 and second part 6144 of the engagement member 614. As the engagement member 614 is connected between the front panel 616 and the fourth side panel 6102, thus the bolt limits the sliding movement of the front panel 616 with respect to the fourth side panel 6102 and thus prevents the removal of the front panel 116 from the enclosure 100. If the bolt is removed from the fourth side panel 6102 by for example a worker using a screwdriver, the front panel 616 can be removed from the enclosure 601 by sliding the front panel 616 along the direction of the front edge 612 of the fourth side panel 6102 even if the front panel 616 is in the closed position.

[090] Further, the enclosure 601 further includes a support base 626. The support base 626 is secured to the back panel 602, particularly on the inner surface of the back panel 602, as shown in Figure 6B. Moreover, the support base 626 includes a first section 6262 of a first height and a second section 6264 of a second height. As exemplarily shown in Figure 6D, the height of the first section 6262 is greater than the height of the second section 6264. Also, the difference in height of the first section 6262 and the second section 6264 is provided to allow electronic devices of different heights to be installed on it. As the electronic devices, such as switches, sockets, and circuit breakers, are available in different sizes, the different heights of sections of the support base 626 allow the electronic devices to be substantially flush with each other in height. For example, a socket with a less height is installed on the higher first section 6262, and a circuit breaker with a greater height is installed on the lower section 6264. This enables the enclosure 601 to accommodate the electrical devices in a neat manner to facilitate access to and inspection and maintenance of the electronic devices.

[091] The enclosure 601 further includes an opening 628. The opening 628 may be provided on at least one of the first side panel 6042 and the second side panel 6062. Further, the opening 628 is sized to fit the three-phase socket 324 as shown in Figure 6A.

[092] Figure 7 illustrates a switchboard 700 with a circuit arrangement in accordance with the present disclosure. The difference between the switchboard 700 and the switchboard 600 is that the switchboard 700 includes a stand 701. The stand 701 is detachably fixed to the enclosure 601 to support the enclosure 601, for example, via one or bolts extending through the hole(s) 615 on the back panel 602 of the enclosure 601.

[093] The stand 701 includes a first support arm 702 and a second support arm 704 to securely and detachably connect to the enclosure 601 via for example, one or bolts extending through the hole(s) 615 on the back panel 602 of the enclosure 601 and the holes on the first support ami 702 and the second support arm 704. Further, the first support arm 702 has a first end 7022 and a second end 7024, and the second support arm 704 has a first end 7042 and a second end 7044. As shown in Figure 7, each of the first support arm 702 and the second support arm 704 is bent at an angle to increase the distance between the second end 7024 of the first support arm 702 and the second end 7044 of the second support arm 704 in order to enhance stability of the switchboard 700.

[094] Further, the stand 701 further comprises a first beam 706 and a second beam 708. The first beam 706 detachably connects the first end 7022 of the first support arm 702 and the first end 7042 of the second support arm 704. The second beam 708 detachably connects the first support arm 702 and the second support arm 704. As shown in Figure 7, the second beam 708 is positioned in the middle segments of the first support arm 702 and the second support arm 704.

[095] Additionally, the stand 701 includes a first support foot 710 and a second support foot 712. The first support foot 710 detachably connects to the second end 7024 of the first support arm 702 and the second support foot 712 detachably connects to the second end 7044 of the second support arm 704. The first support foot 710 and the second support foot 712 are configured to keep the first support ami 702 and the second support arm 704 in an upright positon when in use.

[096] Figure 8 illustrates a perspective view of the first support arm 702 and second support arm 704 in accordance with an embodiment of the invention. The first support arm 702 includes a first angle iron structure and the second support arm 704 includes a second angle iron structure. Each of the first angle iron structure and second angle iron structure has an L shaped cross-section with two legs (i.e., a first leg 805 and a second leg 810 of the first angle iron structure and a first leg 806 and a second 811 of the second angle iron structure). In accordance with one embodiment of the invention, the two legs of each of the first angle iron structure and second angle iron structure may be equal or unequal in length and the angle between two legs is about 90 degrees. Further, in the preferred embodiment of the invention, each of the first leg 805, 806 and the second leg 810, 811 has a length of 30 mm and a thickness between 3.5mm and 5mm. It is noted that the first support arm 702 is also referred to as the first angle iron structure 702 and the second support arm 704 is also referred to as the second angle iron structure 704 in the present disclosure.

[097] Further, the first angle iron structure 702 includes a first pair of switchboard installation holes 815 on the first leg 805 of the first angle iron structure 702 to which the enclosure 601 is secured when in use and the second angle iron structure 704 includes a second pair of switchboard installation holes 820 on the first leg 806 of the second angle iron structure 704 to which the enclosure 601 is secured when in use. Further, the first angle iron structure 702 and the second angle iron structure 704 may be securely connected to the enclosure 601 via bolts through the first pair of switchboard installation holes 815 of the first angle iron structure 702 and the second pair of switchboard installation holes 820 of the second angle iron structure 704.

[098] In accordance with embodiment of the invention, the first angle iron structure 702 includes a first end connection hole 825 on the first leg 805 of the first angle iron structure 702 at the first end 7022 of the first angle iron structure 702. Similarly, the second angle iron structure 704 includes a second end connection hole 830 on the first leg 806 of the second angle iron structure 804 at the first end 7042 of the second angle iron structure 704. Also, the first angle iron structure 702 includes a first middle connection hole 835 on the first leg 805 of the first angle iron structure 702 between the first end 7022 and the second end 7024 of the first angle iron structure 102. Similarly, the second angle iron structure 704 includes a second middle connection hole 840 on the first leg 806 of the second angle iron structure 704 between the first end 7042 and the second end 7044 of the second angle iron structure 704. 1099] In accordance with embodiment of the invention, the first angle iron structure 702 further includes a third end connection hole 845 on the second leg 810 of the first angle iron structure 702 at the first end 7022 of the first angle iron structure 702 and a first pair of holding members 850. Similarly, the second angle iron structure 704 further includes a fourth end connection hole 855 on the second leg 811 of the second angle iron structure 704 at the first end 7042 of the second angle iron structure 704 and a second pair of holding members 860 (not visible in Figure 8, but visible in Figure 10). Further, the second pair of holding member 860 is similar to the first pair of holding member 850, but provided on the second leg 811 of the second angle iron structure 704.

[0100] Figure 9 illustrates a partial perspective view' of the stand 701 in accordance with an embodiment of the invention. As shown in Figure 9, the stand 701 comprises a cable holding assembly 900 to hold a cable, for example, a cable of an electrical tool such as an electrical drill used at the construction site. One end of the cable is connected to the electrical tool, and another end of the cable has a plug, which is plugged into the switchboard for power supply. The cable holding assembly 900 comprises a first support bar 905 and a first cable holding means 910. The first support bar 905 is an elongated structure and the first cable holding means 910 extends from the first support bar 905 to hold a cable. Particularly, the first cable holding means 910 is a U-shaped bar such that the cable can be held in the U-shaped bar. The first cable holding means 910 is able to hold the cable in the air such that the cable does not disturb the worker working near the construction site, for example, causing the worker to fall over. Further, a V-shaped and/or W-shaped or any other shapes of the first holding means 910 can also be used to hold the cable in the air. In accordance with an embodiment of the invention, the material of the cable holding assembly 900 has non-conducting properties. In another embodiment, a non-conducting paint and/or coating may be applied to the cable holding assembly 900, particularly, the first cable holding means 910.

[0101] The stand 701 further includes a first connection means 915 configured to adjustably connect the first support bar 905 of the cable holding assembly 900 to the first support arm 702, namely, the first angle iron structure 702. Particularly, the first connection means 915 allows adjusting the height of the cable holding assembly 900, i.e. the distance from the top of the cable holding assembly 900 to the ground. As a result, the cable holding assembly 900 may be raised to a desired height such that the cable does not disturb the worker working at the construction site. The first support bar 905 of the cable holding assembly 900 includes a third angle iron structure. The third angle iron structure has an L-shaped cross-section with a first leg and a second leg. In accordance with one embodiment of the invention, the two legs may be equal or unequal in length and the angle between two legs is about 90 degrees. Each of the first leg and the second leg of the third angle iron structure has a length of 20 mm and a thickness of 3 mm. The first support bar 905 is also referred to as the third angle iron structure 905. The third angle iron structure 905 is adapted to be mounted onto the first angle iron structure 702 using the first pair of holding members 950 and the first connection means 915.

[0102] Further, the first pair of holding members 950 and the two legs (the first leg 805 and the second leg 810) of the first angle iron structure 702 are configured to be able to surround the third angle iron structure 905 of the cable holding assembly 900 when the third angle iron structure 905 is positioned between the first pair of holding members 950 and the two legs (the first leg 805 and the second leg 810) of the first angle iron structure 702. For example, when assembling the stand 701, the third angle iron structure 905 is slid along the first angle iron structure 702 such that the third angle iron structure 905 is held between the first pair of holding members 950 and the tw o legs (the first leg 805 and the second leg 810) of the first angle iron structure 702. The position to which the third angle iron structure 905 is slid along the first angle iron structure 702 can be changed in order to adjust the height of the cable holding assembly 900, i.e., the distance from the top of the cable holding assembly 900 to the ground. In an embodiment, to connect the third angle iron structure 905 of the cable holding assembly 900 to the first angle iron structure 702, the first connection means 915 of the cable holding assembly 900 is a first location bolt. The first location bolt is configured to engage with the third end connection hole 845 via the threads on the first location bolt and the third end connection hole 845. As the first location bolt is rotated in a direction manually or by a torque wrench, the first location bolt extends through the third connection hole 845 and firmly presses the third angle iron structure 905 of the cable holding assembly 900 against the first pair of holding members 950 of the first angle iron structure 702. As a result, the first location bolt connects the third angle iron structure 905 to the first angle iron structure 702 at a certain height. If the height of the cable holding assembly 900 needs to be changed, the first connection means 915 (particularly, the first location bolt) is rotated in an opposite direction in order to detach the third angle iron structure 905 from the first angle iron structure 702. Then the third angle iron structure 905 is moved along the first angle iron structure 702 to a different position, resulting in an adjusted height of the cable holding assembly 900, and can be connected to the first angle iron structure 702 by the first location bolt at the adjusted height. This way, the first location bolt is able to adjustably connect the third angle iron structure 905 of the cable holding assembly 900 to the first angle iron structure 702. In accordance with an embodiment of the invention, the first connection means 915 is an eye bolt. Further, other types of bolts may also be used such as, but not limited to, triangular head handle bolts, circular head bolts, pigtail bolts, T-bolts etc.

[0103] Figure 10 illustrates a partial perspective view of the stand 701 in accordance with an embodiment of the invention. As shown in Figure 10, the stand 701 further comprises a lamp installation assembly 1001. The lamp installation assembly 1001 includes a second support bar 1005 and a lamp installation means 1010. The lamp installation assembly 1001 is generally an elongated structure and capable of holding a lamp (not shown in Figure 10), which allows fixing a lighting lamp to illuminate the area around the stand 701.

[0104] As shown in Figure 10, the lamp installation means 1010 extends from the second support bar 1005 such that lamp can be mounted on the lamp installation means 1010. The second support bar 1005 of the lamp installation assembly 1001 includes a fourth angle iron structure. The fourth angle iron structure has an L shaped cross-section with a first leg and a second leg. In accordance with one embodiment of the invention, the two legs may be equal or unequal in length and the angle between two legs is about 90 degrees. Each of the first leg and the second leg of the fourth angle iron structure has a length of 20 mm and a thickness of 3 mm. The second support bar 1005 is also referred to as the fourth angle structure 1005.

[0105] In accordance with an embodiment of the invention, the lamp installation means 1010 is a straight bar with at least one hole such that the lamp can be installed on the straight bar via at least one bolt through the at least one hole. However, the stand 701 further includes a second connection means 1015 configured to adjustably connect the second support bar 1005 to the second support arm 704, namely, the second angle iron structure 704.

[0106] As shown in Figure 10 the second angle iron structure 704 includes the second pair of holding members 860. The second pair of holding member 860 and the two legs of the second angle iron structure 704 surround the fourth angle iron structure 1005 of the lamp installation assembly 1001. In the embodiment shown in Fig. 10, the second connection means 1015 of the stand 701 is a second location bolt. Similar to the first location bolt, the second location bolt is configured to engage with the fourth end connection hole 855 via the threads on the second location bolt and the fourth end connection hole 855. As the second location bolt is rotated manually or by a torque wrench, the second location bolt extends through the fourth end connection hole 855 and firmly presses the fourth angle iron structure 1005 of the lamp installation assembly 1001 against the second pair of holding members 860 of the second angle iron structure 704. This way, similar to the first location bolt and the first pair of holding members 950, the second location bolt adjustably connects the fourth angle iron structure 1005 of the lamp installation assembly 1001 to the second angle iron structure 704. The second location bolt is an eye bolts. Further, other types of bolts may also be use such as, but not limited to, triangular head handle bolt, circular head bolts, pigtail bolts, T-bolt etc.

[0107] Figure 11 illustrates a partial perspective view of the stand 701 in accordance with an embodiment of the invention. As shown in Figure 11, the first beam 706 includes a first pair of connection holes 1110, 1120, such that the first beam 706 detachably connects to the first end 7022 of the first angle iron structure 702 and the first end 7042 of the second angle iron structure 704 via a first connection bolt 1105 and a second connection bolt 1115. The first connection bolt 1105 extends through the first end connection hole 825 of first angle iron structure 702 and one (i.e., the connection hole 1110) of the first pair of connection holes of the first beam 706. The second connection bolt 1115 extends through the second end connection hole 830 of the second angle iron structure 704 and another one (i.e., the connection hole 1120) of the first pair of connection holes of the first beam 706. The first connection bolt 1105 and the second connection bolt 115 are hexagonal head bolts with washers. Moreover, the hexagonal head bolt includes a nut to fasten the first beam 706 with the stand 701. In accordance with one embodiment of the invention, the first connection bolt 1105 and second connection bolt 1115 is one of, but not limited to, T-bolts, hex-socket bolts and elevator bolts. Further, any other types of fastening means can also be used to detachably connect the first beam 706 to the first angle iron structure 702 and the second angle iron structure 704.

[0108] In accordance with an embodiment of the invention, the second beam 708 further includes a cable winding means 1125. The cable winding means 1125 extends from a first position 1130 on the second beam 708 and ends at a second position 1135 on the second beam 708. As described above, the cable is held by the cable holding means 910 (particularly, the U-shaped bar) of the cable holding assembly 900 in the air and extends down to the cable winding means 1125. The cable can be wound around the cable winding means 1125 between the first position 1130 and the second position 1135. Therefore, the cable will not become tangled and the plug on the other end of the cable can be easily accessed and plugged into the socket of the switchboard. Moreover, the cable winding means 1125 of the second beam 708 is covered by an electrical insulation material. This is to avoid an electric shock if there is an electric current flowing through the cable winding means 1125 due to a worn or torn cable, thus providing a safety feature to the stand 701.

[0109] Further, the second beam 708 includes a second pair of connection holes 1140, 1141, such that the second beam 708 detachably connects the first angle iron structure 702 and the second angle iron structure 704 via a third connection bolt 1145 and a fourth connection bolt 1150. The third connection bolt 1145 extends through the first middle connection hole 835 of the first angle iron structure 702 and one (i.e., the connection hole 1140) of the second pair of connection holes of the second beam 708. The fourth connection bolt 1150 extends through the second middle connection hole 840 of the second angle iron structure 704 and another one (i.e., the connection hole 1141) of the second pair of connection holes of the second beam 708.

[0110] Coming back to Figure 7. As shown in Figure 7, the first support foot 710 includes a fifth angle iron structure and the second support foot 712 includes a sixth angle iron structure. Further, each of the fifth angle iron structure and the sixth angle iron structure has an L shaped cross-section with two legs. The two legs may be equal or unequal in length and the angle between two legs is about 90 degrees. Each of the two legs has a length of 40 mm and a thickness between 3mm and 5mm.

[0111] As described above, angle iron structures are used to make the stand 701. However, in other embodiments of the invention, other metallic structure such as rods, bars, channels may also be used.

[0112] As described above, since the connections between the parts of the stand 701 are detachable, when the stand 701 is used, a user only needs to assemble these parts to form the stand 701 as shown in the figures. If the stand 701 is not in use, the stand 701 can be disassembled into the parts, this allows the parts of the stand 701 to be stored and transported separately. Further, the selected specifications of the angle iron structures provide the stand 701 with sufficient strength to perform their respective functions and also make the stand 701 lightweight.

[0113] The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Examples and limitations disclosed herein are intended to be not limiting in any manner, and modifications may be made without departing from the spirit of the present disclosure. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the disclosure, and their equivalents, in which all terms are to be understood in their broadest possible sense unless otherwise indicated.

[0114] Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is meant to provide the broadest scope, consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the disclosure is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present disclosure and appended claims.

Claims (25)

1. Claims The claims defining the present invention are as follows:

   1. A circuit arrangement of a switchboard for connecting a power supply including an active wire, a neutral wire and an earth wire to a socket including an active pin, a neutral pin and an earth pin, the circuit arrangement comprising: a first switch having a first contact terminal and a first associated contact terminal, the first contact terminal of the first switch being configured to electrically connect to the active wire of the power supply in use; a first terminal block electrically connected to the first associated contact terminal of the first switch; a second switch having a second contact terminal and a second associated contact terminal, the second contact terminal of the second switch being configured to electrically connect to the first terminal block, and the second associated contact terminal of the second switch being electrically connected to the active pin of the socket; a second terminal block configured to electrically connect to the neutral wire of the power supply in use and to the neutral pin of the socket; and a third terminal block configured to electrically connect to the earth wire of the power supply in use and to the earth pin of the socket.
2. 2. The circuit arrangement of claim 1, further comprising a circuit protection device between the second associated contact terminal of the second switch and the active pin of the socket, the circuit protection device electrically connecting the second associated contact terminal of the second switch to the active pin of the socket.
3. 3. The circuit arrangement of claim 2, wherein the circuit protection device comprises a residual circuit breaker with overcurrent protection (RCBO).
4. 4. The circuit arrangement of claim 3, wherein the second terminal block is electrically connected to the neutral pin of the socket via the RCBO.
5. 5. The circuit arrangement of claim 1, wherein the first terminal block comprises: a first connection mechanism connected to a first conductive wire that is connected to the first associated contact terminal of the first switch; a second connection mechanism connected to a second conductive wire that is connected to the second contact terminal of the second switch; and a third connection mechanism configured to connect to a third conductive wire that is connected to the first contact terminal of the first switch of a further switchboard.
6. 6. A circuit arrangement of a switchboard for connecting a power supply including a first active wire, a second active wire, a third active wire, a neutral wire and an earth wire to a socket including a first active pin, a second active pin, a third active pin, a neutral pin and an earth pin, the circuit arrangement comprising: a first switch having a first contact terminal and a first associated contact terminal, the first contact terminal of the first switch being configured to electrically connect to the first active wire of the power supply in use; a second switch having a second contact temiinal and a second associated contact terminal, the second contact terminal of the second switch being configured to electrically connect to the second active wire of the power supply in use; a third switch having a third contact terminal and a third associated contact temiinal, the third contact terminal of the third switch being configured to electrically connect to the third active wire of the power supply in use; a first terminal block electrically connected to the first associated contact tenninal of the first switch; a second temiinal block electrically connected to the second associated contact terminal of the second switch; a third tenninal block electrically connected to the third associated contact terminal of the third switch; a fourth switch having a fourth contact temiinal and a fourth associated contact terminal, the fourth contact terminal of the fourth switch being configured to electrically connect to the first terminal block, and the fourth associated contact terminal of the fourth switch being electrically connected to the first active pin of the socket; a fifth switch having a fifth contact terminal and a fifth associated contact terminal, the fifth contact terminal of the fifth switch being configured to electrically connect to the second terminal block, and the fifth associated contact terminal of the fifth switch being electrically connected to the second active pin of the socket; a sixth switch having a sixth contact terminal and a sixth associated contact terminal, the sixth contact terminal of the sixth switch being configured to electrically connect to the third terminal block, and the sixth associated contact terminal of the sixth switch being electrically connected to the third active pin of the socket; a fourth terminal block configured to electrically connect to the neutral wire of the power supply in use and to the neutral pin of the socket; and a fifth terminal block configured to electrically connect to the earth wire of the power supply in use and to the earth pin of the socket.
7. 7. The circuit arrangement of claim 6, further comprising: a first circuit protection device between the fourth associated contact terminal of the fourth switch and the first active pin of the socket, the first circuit protection device electrically connecting the fourth associated contact terminal of the fourth switch to the first active pin of the socket; a second circuit protection device between the fifth associated contact tenninal of the fifth switch and the second active pin of the socket, the second circuit protection device electrically connecting the fifth associated contact terminal of the fifth switch to the second active pin of the socket; and a third circuit protection device between the sixth associated contact terminal of the sixth switch and the third active pin of the socket, the third circuit protection device electrically connecting the sixth associated contact terminal of the sixth switch to the third active pin of the socket.
8. 8. The circuit arrangement of claim 7, wherein the first circuit protection device comprises a first circuit breaker (CB) and a first residual current device (RCD), the second circuit protection device comprises a second CB and a second RCD, and the third circuit protection device comprises a third CB and a third RCD.
9. 9. The circuit arrangement of claim 8, further comprising a fourth RCD between the fourth terminal block and the neutral pin of the socket, the fourth RCD electrically connecting the fourth terminal block to the neutral pin of the socket.
10. 10. A switchboard, comprising: a circuit arrangement of any one of claims 1 to 9; and an enclosure configured to carry the circuit arrangement, the circuit arrangement being secured to enclosure, the enclosure comprising: a back panel having a first side edge, a second side edge, a third side edge and a fourth side edge; a first side panel extending from the first side edge of the back panel; a second side panel extending from the second side edge of the back panel; a third side panel extending from the third side edge of the back panel; a fourth side panel extending from the fourth side edge of the back panel and forming a front edge, the fourth side panel being adjacent to the first side panel and the second side panel; an engagement member having a first part and a second part, the first part of the engagement member being securely fixed to the fourth side panel, wherein the second part is configured to be pivotable relative to the first part and further configured to slide relative to the first part along a direction of the front edge of the fourth side panel to allow engagement with and disengagement from the first part along the direction of the front edge of the fourth side panel; and a front panel securely fixed to the second part of the engagement member.
11. 11. The switchboard of claim 10, wherein the fourth side panel is configured to be horizontal when in use.
12. 12. The switchboard of claim 10, wherein the fourth side panel is configured to be vertical when in use.
13. 13. The switchboard of claim 11 or 12, the enclosure further comprises a movement limiter detachably connected to the fourth side panel, the movement limiter being configured to limit the sliding of the second part of the engagement member relative to the first part of the engagement member in order to disable the disengagement of the second part from the first part.
14. 14. The switchboard of claim 13, wherein the second part of the engagement member includes an elongate pin and the first part of the engagement member includes an elongate hollow member configured to slidely and pivotably receive the elongate pin therein.
15. 15. The switchboard of claim 13, wherein the first part of the engagement member includes an elongate pin and the second part of the engagement member includes an elongate hollow member configured to slidely and pivotably receive the elongate pin therein.
16. 16. The switchboard of claim 14 or 15, wherein the movement limiter is a bolt and the fourth side panel includes a hole with a thread to detachably connect the bolt to the fourth side panel via the thread.
17. 17. The switchboard of claim 16, wherein the hole is located at a position where if the bolt is screwed into the fourth side panel, the bolt disables the disengagement of the second part of the engagement member from the first part of the engagement member.
18. 18. The switchboard of claim 17, the enclosure further comprises a support base secured to the back panel, the support base having a first section of a first height and a second section of a second height and being configured to allow electronic devices of different heights to be installed thereon.
19. 19. The switchboard of claim 10, wherein at least one of the first side panel and the second side panel includes a further opening, the further opening being sized to fit a three-phase socket.
20. 20. The switchboard of claim 10, further comprising a stand that is connected to the enclosure to support the enclosure, the stand comprising: a first support arm to securely and detachably connect to the enclosure; a second support arm to securely and detachably connect to the enclosure, each of the first and the second support arms having a first end and a second end; a first beam to detachably connect the first end of the first support arm and the first end of the second support arm; a second beam to detachably connect the first support arm and the second support arm a first support foot to detachably connect to the second end of the first support arm; a second support foot to detachably connect to the second end of the second support arm, wherein the first support foot and the second support foot are configured to keep the first support arm and the second support arm in an upright positon when in use.
21. 21. The switchboard of claim 20, the stand further comprises: a cable holding assembly, the cable holding assembly comprising: a first support bar; and a first cable holding means that extends from the first support bar to hold a cable; and a first connection means configured to adjustably connect the first support bar to the first support arm.
22. 22. The switchboard of claim 21, wherein the first cable holding means is a U-shaped bar such that the cable can be held by the U-shaped bar.
23. 23. The switchboard of claim 22, the stand further comprises: a lamp installation assembly, the lamp installation assembly comprising: a second support bar; and a lamp installation means that extends from the second support bar for installation of a lamp thereon; and a second connection means configured to adjustably connect the second support bar to the second support arm.
24. 24. The switchboard of claim 23, wherein the lamp installation means is a straight bar with at least one hole such that the lamp can be installed on the straight bar via at least one bolt through the at least one hole.
25. 25. The switchboard of claim 24, wherein the second beam further includes a cable winding means, the cable winding means extending from a first position on the second beam and ends at a second position on the second beam such that the cable can be wound around the cable winding means between the fust position and the second position.