WO2013019118A2

WO2013019118A2 - Moulded electrotechnical protection component

Info

Publication number: WO2013019118A2
Application number: PCT/NO2012/050127
Authority: WO
Inventors: Bjørn FOSSEN; Vidar BIRKELAND
Original assignee: Vik Ørsta As
Priority date: 2011-06-29
Filing date: 2012-06-29
Publication date: 2013-02-07
Also published as: EP2727123B1; NO20110940A1; DK2727123T3; NO334147B1; WO2013019118A3; EP2727123A2

Abstract

Molded electrical protection component with encapsulation devices suited to protect the component against ingress of solid objects and fluids, where the encapsulation devices comprise molding compound that surround parts of the component in order to contribute to achieve an improved degree of encapsulation, and where the molded component further comprises safety devices for handling of ionized gas formed in the case of short circuit currents in the protection component, and a corresponding method.

Description

MOULDED ELECTROTECHN I CAL PROTECTI ON COMPONENT

The present invention generally relates to encapsulation technology for electrical safety components and safety in this context. More particularly the invention relates to molded circuit breakers, automatic earth fault circuit breakers, earth fault circuit breakers, power switches, manual motor protection switches and the like, or combinations of these together with other electrical equipment.

Specifically, the invention relates to a molded protection component according to claim 1, comprising safety devices for the handling of ionized gases formed in the case of short circuit currents in the protection component.

Background of the Invention

In many situations it is relevant to apply modular electrical components in challenging environments. In this context, the voltage level is typically below 1 kV, and most typically from 100 to 400 volts. The environment may be particularly humid, dusty or exposed to explosion hazard in connection with explosive gases. Other examples of demanding environments are aggressive atmosphere, high pressure washing, talc,

condensation and flooding. Such conditions naturally make special demands on the equipment. Demands of this nature are dealt with in various standards, regulations and norms, and more. Below are examples of relevant such.

IEC 400 is a standard developed by the Norwegian Electro

Technical Committee (NEK) , and provides requirements for electrical low voltage installations.

The FEL regulations ("Regulations on electrical low voltage installation with instructions") are based on the requirements for low voltage installations related to fire, function and El Safety. NEK 400 serves as a guide for how this may be achieved through specific technical requirements. The IP system is a system to specify the encapsulation degree for electrical equipment, i.e. the protection of equipment against ingress of solid objects and water. It is an

international standard defined in IEC 60529 published by the International Electro Technical Commission. In Norway it has been translated by Norwegian Electro Technical Committee as EN IEC 60529. The degree of encapsulation is designated by the letters IP (abbreviation for "international protection

rating") followed by two digits. German standard DIN 40050-9 exceeds IEC 60529 by a

designation, IP69K, for equipment that can withstand high pressures, high temperatures and strong water current. The test standard for IP69K specifies a nozzle supplied with water at a temperature of 80 °C, a pressure of 8-10 MPa (80-100 bar) and a flow of 14-16 L/min. IP69K was originally developed for vehicles, especially those which need regular heavy cleaning, but is now used in other areas such as food industry.

Ex-equipment, or explosion-protected equipment, characterizes equipment, both electrical an non electrical equipment that is not subject to special approval and/or certification according to European or international standards of IEC/TC31, CLC/TC31 or CEN 305. In Norway, this relates to equipment in accordance with Norwegian regulations under ATEX Directive 94/9, called FUSEX. The norms that regulate this are: the NEK EN 60079 series or the NS EN 13463 series for not electrical equipment. "Low Voltage Directive" is the primary legislation within the European Economic Area for electrical low voltage equipment. The requirements of the Directive are set out in regulations relating to electrical equipment (FEU) in 1995 and the regulations enforced by the Directorate for Civil Protection and Emergency Planning (DSB) .

Demanding environments generally pose a need for protection of electrical systems to operate in such. In the following we will describe examples of problems related to low voltage switch equipment more specifically.

In dry environments such as a desert, dust intrusion is a problem. Dust intrusion could be an obstacle to mechanical function, increase wear by friction, reduce electrical contact, and (as a result of the above,) reduce the life time and increase maintenance costs. In humid environments such as inside a lamp post, the ingress of water or condensation would be a problem. Humidity will, for example, lead to reduced electrical contact, short-circuit problems, ground fault, touch-risk and increased corrosion. These phenomena also will lead to increased maintenance costs and reduced life time. In environments with explosive gases the leakage into the switch equipment could lead to explosion danger.

A more concrete example of a relevant issue is the

installation of automatic circuit breakers in light posts. The environment inside a light post can be very humid in the form of condensation due to temperature fluctuations. Condensation will form inside the cavity of the light post and equipment located therein. Condensed moisture will also be able to flow along vertical elements and thereby penetrate inadequately sealed elements that are mounted inside the pole. The issue of installing automatic circuit breakers in light poles has been highlighted in recent years. Earlier one-phase- fuses satisfied the relevant standards, but now protection is required in both phases. This is not possible by means of melting fuses that were frequently used in this regard.

It is well known to mount electrical protection components in boxes to increase the encapsulation degree. An example of a standard solution according to prior art is a box for

encapsulation of automatic circuit breaker. Such a solution does, however, pose a number of problems. To achieve a degree of encapsulation from IP65 upwards, lids must be attached to the boxes with a number of locking points. Furthermore, the boxes should be mounted in a controlled environment with proper tightening of any contact screws and cable glands. Any cable entry can cause problems with unwanted water intrusion as a result of condensation. Furthermore, the screws that are through-going and screws for the lid cause problems with securing the IP degree.

Solutions according to prior art will reduce problems of the character described in the introduction. However, as indicated above a number of problems will not be solved. A first problem is that the encapsulation rating will not be sufficient.

Humidity will be able to penetrate into the box, or build up inside the box in the form of condensation. Thus there will be subsequent problems in the form of, for example, reduced functionality, reduced safety, increased maintenance costs and reduced life time as described. Sealing problems are

exacerbated by the fact that the box consists of a number of parts that must be assembled, lead-through of various items such as fasteners in the form of e.g. screws, electrical cables. Furthermore, solutions according to prior art result in problems by mounting e.g. by manual tightening of screws. Furthermore, certain current system solutions will be either impossible, or complex and costly. Maintenance will also be complicated and costly. Acquisition and maintenance costs and hence lifetime costs might be high.

A further central problem with prior art, is safety in connection with short-circuit currents in the protection component in which the formation of expanding ionized gases that cause a risk in that a molded electrical component could explode. Such an explosion would pose a safety hazard for personnel who are close to the molded electrical component. In addition, an explosion could damage the component itself and any other equipment nearby. Consequential damages are also a danger in this context.

Thus there is still a need to solve a number of problems as discussed above. These issues are addressed largely by the present invention.

Summary of the invention

In general, the objectives of the invention are to solve problems of prior art as described in the preceding chapter. The objectives are more specifically described in the

following .

The overall purpose of the present invention is to provide a solution that can be used in more demanding environments in the form of, for example, moisture, dust, aggressive

atmosphere and danger of explosion. Additional objectives of the invention are increased safety, longer lifetime, lower acquisition costs, lower installation and operating costs, and easier and safer installation. A further objective of the present invention is to provide a solution that gives enhanced degree of encapsulation for electrical protection components.

A further objective is to achieve improved solutions by application of molded protection components in many contexts, as detailed below.

A key objective is to improve safety. In particular, this applies to safety related to explosion danger in the case of short-circuit currents in the protection component. A specific objective here is to control emissions of expanding, ionized gases .

An objective of stepwise handling is to improve safety by reducing the risk for the environments in the case of a short circuit. In the case of a minor short-circuit the emission of ionized gas from the molded component could be prevented and in the case of larger explosions, the effect is reduced. A further objective of the stepwise handling is to reduce costs and resource use by possible reuse of molded protection components after explosion.

The objectives are achieved by a solution according to the invention as defined in the independent patent claim, while embodiments of the invention are defined in the dependent claims . The invention relates to molded electrical safety component comprising at least one electrical connection device and further molding devices to protect said breaker material against the ingress of solid objects, gases and fluids. The aforementioned molding devices comprise molding compound and an outer mold, where the molding compound is arranged in contact with the outer parts of the breaker material to help achieve an improved degree of encapsulation. Embodiments of the molded breaker material have encapsulation degrees from at least IP44 and up to an encapsulation degree corresponding to IP69K.

In different embodiments, the electrical safety component may comprise an automatic circuit breaker, an ground fault automat, a ground fault circuit breaker, a power breaker, or the like being molded.

In further embodiments the molded low voltage circuit breaker material further comprises at least one other electrical device that can also be molded.

The breaker material may comprise one or more standard products which typically also may be modular. The electrical connection devices of the molded low voltage circuit breaker material may in various embodiments comprise at least a male or female connector, at least a Schuko connector, coupling clamps/pieces or at least an electrical cable. The above forms of connection devices may in some contexts advantageously be combined. The electrical connection devices can be molded into a common molding compound with a molded breaker unit which helps to secure the desired degree of sealing. In a further embodiment the breaker unit may comprise a manual control device an encapsulation device for said manual control device in the form of either a flexible membrane, a flip lid or a lid that can be attached using fasteners such as for example screws.

Said flexible membrane allows for operation of the manual control device with the membrane closed. Parts of the membrane can advantageously border the molding compound so that the molding compound and the membrane is comprised by an

integrated solution that contributes to a degree of enclosure of IP69K.

In a further embodiment a mechanical fastener for the breaker material is fixed by means of the molding compound. Such a fastener may for example comprise a wall mount or pole mount. The solution can provide a good hold without the use of e.g. screws .

The molding compound may comprise either one-component molding compound or two-component molding compound such as epoxy, polyurethane or the like.

Molded breaker material according to the embodiments described above may advantageously be applied in food production, pulp and paper industry, in connection with railways, car washes, road lighting, recreational boats, commercial boats, caravans, machinery, tools, power outlets, distributions, street lighting, charging stations or the like. Of interest in this context is applications in corrosive environments (for example for pulp and paper) . Other aspects and advantages of the invention will appear from the following description and the attached claims.

Brief description of drawings

Figure 1 shows a cross section of an embodiment of the invention in the form of a molded automatic circuit breaker where the connection devices consist of electric cables.

Figure 2 shows a cross section of an embodiment of the invention in the form of a molded automatic circuit breaker where the connection devices consists of a male and a femal connector .

Figure 3 shows a cross section of an embodiment of the invention in the form of a molded automatic circuit breaker where the connection devices consist of a Schuko connector and an electric cable.

Figure 4 shows cross section of an embodiment of the invention where the closures of the manual control devices comprise a flexible membrane.

Figure 5 shows cross section of an embodiment of the invention where the closures of the manual control devices comprise a lid that can be screwed.

Figure 6 shows the cross section of an embodiment of the invention where the closures of the manual control devices comprises a flip lid. The figures 7, 8 and 9 show the various views and sections of a protection component according to the invention, as detailed below .

Figures 7A, 8A and 9A show a view of a molded protection component according to the invention, viewed from a side of the component where there is mounted an electric cable. Figures 7B, 8B and 9B show a longitudinal section of a molded protection component according to the invention, where the location of the safety devices for emission (handling) of ionized gases are highlighted. Figures 7C, 8C and 9C show an enlarged, longitudinal cross- section of the safety devices for emission (handling) of ionized gases are highlighted at various phases of an emission process. Detailed description of the invention

Figure 1 schematically shows an embodiment of the invention where the electronic protection component in the form of automatic circuit breaker (2) is molded in molding compound (6) . The safety devices for emission (handling) of ionized gases are not shown in this figure, nor in Figures 2 to 6.

Said safety devices, however, are particularly highlighted in the Figures 7A-C, 8A-C and 9A-C which are described in detail below . The connection devices for the automatic circuit breaker (1) here consist of two electrical cables (5a, 5b) where one electric cable (5a) is typically connected to supply, while the other electric cable (5b) typically may be connected to a load such as in the form of a luminaire.

The automatic circuit breaker (2) comprises a control device (4) in the form of a toggle switch (4a), which allows manual operation. The molding devices comprise an outer mold (7) that defines the shape of the main part of the molded automatic circuit breaker (1) . The mold (7) and the automatic circuit breaker (2) and the location of these relative to each other, mainly determine the final shape of the molding compound (6) .

When designing an embodiment of the invention in the form of a molded automatic circuit breaker (1), there are numerous aspects / requirements / criteria that should be taken into account. Dimensioning of the molding devices (6, 7) is done primarily to help ensure the optimal encapsulation degree, but additionally thermal conductivity, weight, space for

encapsulation of elements, as e.g. connection devices (5a, 5b), in addition to the automatic circuit breaker (2) and the ability to mechanically lock these items, should be taken into account, among other things. In the embodiment in the figures there is a layer of molding compound (6) arranged so that it is thin at the relevant parts of the top and the bottom and the lateral side surfaces of the automatic circuit breaker (2), while it is relatively thick at the end surfaces (top / bottom). The thin sections of the molding compound (6) help to ensure good thermal conductivity from the automatic circuit breaker (2) . The molding compound (6) may advantageously be of a heat conductive type. While the thick areas add volume to effectively integrate equipment for example in the form of connection devices (5a, 5b) . An automatic circuit breaker (2) typically comprises a main part whose main function is to break the circuit in the case of faults, in order primarily to secure the cable network against loads for which it is not dimensioned. There are automatic circuit breakers (2) for one- and multi-pole break, but requirements for two- or multi-pole breaks are becoming more common.

The electrical components which are molded will typically be standard equipment. Thus there will normally be no need to acquire dedicated products that will often be

disproportionately costly. The products may also be modular. Standard, modular products in molded version, however, normally will differ in size from the standard. Molded versions of standard size might be obtained by producing circuit breaker material adapted for molding in smaller size.

The degree of encapsulation of an automatic circuit breaker (2) is determined by the encapsulation solution for the elements which the automatic circuit breaker (2) comprises; in other words the main part, the connection devices and possibly the manual control devices (4) with closures (8), where the closures (8) will normally be transparent. In connection with the encapsulation the challenges and the solutions will be different for said three groups of elements. Furthermore, it will be of great importance how the encapsulation devices for said three groups of elements are integrated. We will go into this more closely in the further. Finally in this context it should be noted that the degree of encapsulation of a standard automatic circuit breaker is IP20.

Figure 1 shows an embodiment of the invention in accordance with the common description of Figure 1-3 above. The electrical connection devices here comprise two electrical cables (5a, 5b), where one electrical cable (5a) is arranged typically for being connected to supply, while the other (5b) typically is arranged for being connected to load for example in the form of a luminaire.

This embodiment will be able to achieve a high encapsulation degree such as IP69K (ref the chapter concerning the

Background of the invention) , and thus be used in extremely demanding conditions (see below) . The electrical cables (5a, 5b) are here connected directly to the automatic circuit breaker (2) . Thus the connection devices (5) do not have to comprise connectors or plugs. Connectors and plugs are

elements that typically result in lower degree of

encapsulation. For instance, a Schuko connector provided with a flip lid gives an encapsulation degree of IP44.

Molding of the electrical cables (5a, 5b) helps to achieve the aforementioned, high encapsulation degree. The molding

compound (6) will effectively seal around the cables (5a, 5b) along relatively long sections of these by the connecting points with the automatic circuit breaker (2) . The molding compound (3) will typically be slightly expandable, which contributes further to ensure sealing not only against the said electric cables (5a, 5b) , but generally for the solution.

Another advantage of the embodiment with directly connected conductors (5a, 5b), is that production and maintenance are simplified, and that the acquisition and maintenance costs are reduced. Molding of the electrical cables (5a, 5b) thus contributes significantly to achieving the high encapsulation degree of this embodiment. Figure 2 shows a further embodiment where the connection devices comprise a male and a female plug (5c, 5d) to which electrical cables with corresponding male and female

connectors can be connected. The male and female plug (5c, 5d) are further connected to the automatic circuit breaker (2) by means of cables. The latter cables are for convenience not included in the figure.

This embodiment will also be able to achieve a relatively high encapsulation degree as e.g. IP67 or IP68 (ref the chapter regarding the Background of the invention) , and thus be used under demanding conditions (see below) . While this embodiment can provide high encapsulation degree, adjacent equipment is connected using separate cables, which can be beneficial for production and installation.

Figure 3 shows a further embodiment in which the connection devices include a Schuko connector (5f), to which the

electrical cables with corresponding plug can be connected. The Schuko connector (5f) is further connected to the automatic circuit breaker (2) by means of cables. The latter cables are for convenience not included in the figure.

This embodiment typically offers e.g. IP44 (ref the chapter regarding Background for the invention), i.e. a slightly lower encapsulation degree than the embodiments mentioned above.

The figures 4, 5 and 6 illustrate embodiments with various versions of encapsulation devices / closures (8) for the manual control devices (4) . The manual control devices (4) for an automatic circuit breaker (2) comprises a rocker switch (4a) arranged to manually open and close the current circuit. The encapsulation devices of the manual control devices (4) help ensure appropriate encapsulation degree of the encapsulated automatic circuit breaker (1) while manual operation is still possible. Solutions that provide easy access to the manual control devices (4) for example in the form of a flip lid, may be unfavorable in terms of achieving a good encapsulation degree. The properties of the molded automatic circuit breaker (1) will depend on a good solution for how the encapsulation devices for the manual control devices (4a) are integrated with the enclosures of the main part of the automatic circuit breaker (2) .

Figure 4 schematically shows a particularly beneficial embodiment where the encapsulation devices for the manual control devices (4) comprise a flexible membrane (8a). Such a membrane (8a), may be made of silicone. The flexible membrane (8a) allows manual operation of the manual

control devices (4) without the encapsulation devices for the manual control devices (4) needing to be opened and,

consequently, without tools; in other words, this embodiment has good ergonomic qualities. Furthermore, the edge of the flexible membrane (8a) may be molded using the molding compound (6). Thus, the encapsulation devices for the

automatic circuit breaker (2) and the manual control devices (4) constitute a continuous encapsulation solution. This allows to provide an optimal encapsulation degree. The embodiment is further constructed so that it does not prevent automatic tripping (release) in the case of overload or short circuit. Further, the embodiment will have low complexity in that it comprises a relatively small number of structural elements, while the maintenance will be easy. The solution could also be economically beneficial in terms of both acquisition and maintenance costs. Finally, regarding this embodiment it is pointed out that one achieves a high degree of encapsulation of IP69K, and that this is combined with other favorable properties as detailed above.

Figure 5 shows an embodiment where the encapsulation devices for the manual control devices (4) comprise a lid attached with fasteners (8b) , for example in the form of screws, where the lid typically rests against a packing to improve the degree of encapsulation. The lid (8b) must be opened for operation of the manual control devices (4); an operation that requires the use of tools. The ergonomics are therefore considered not to be particularly good. Furthermore, here too the edge of lid devices (8b) are molded using molding

compound. The encapsulation devices for the automatic circuit breaker (2) and the manual control devices (4) do not

constitute a continuous encapsulation solution, but a lid attached with fasteners provide good encapsulation degree. The degree of encapsulation which can be provided by means of this solution will be IP69K. Figure 6 shows an embodiment where the encapsulation devices for the manual control devices (4) includes a flip lid (8c) . The flip lid devices (8c) must be opened for operation of the manual control devices (4), but does not require any tools. Thus, associated ergonomic properties are considered to be relatively good. Furthermore, the edge of the flip lid devices (8c) is molded using the molding compound. The encapsulation devices for the automatic circuit breaker (2) and the manual control devices (4) , however, do not constitute a continuous encapsulation solution because the flip lid ensures enclosure using packing devices. The degree of encapsulation that can be provided by means of this solution will typically be IP66-67. The figures 1 to 6 described above, present primarily the encapsulation devices according to the invention.

Safety devices to emit (handle) expanding ionized gases formed during short-circuit currents are key features of the

invention as illustrated in subsequent figures.

Figure 7A, 8A and 9Ά show views of a molded protection component (1) according to the invention, seen towards one side of the component where an electric cable is mounted. The electrical cable is brought into the molded protection component through a hole or recess in an end wall of the house. In these holes or recesses is further arranged a sealing element which will be described in more detail in connection with Figures 7B, 8B and 9B.

At the edges of the end walls there is illustrated a cable tightening which helps to ensure that the cable conduit is tight against the molding compound.

Just over the end wall one sees the face of the encapsulation devices for the manual control devices described in more detail above. Finally, regarding the figures 7A, 8A and 9A, we mention that the broken lines AA, BB and CC are only included to illustrate where the transverse direction of the longitudinal section as presented in Figures 7B, 8B and 9B is placed. Figure 7B, 8B and 9B show a longitudinal section of a molded protection component (1) according to the invention, where the approximate location of the safety devices for the emission of ionized gases is highlighted by a dotted circle at bottom right of the figures.

The technical function of said safety devices (explosion protection) is described in the following.

In the case of a short circuit in the protection component, which here consists of a circuit breaker (2), ionized gases at high temperature will be produced. These gases will increase the pressure in the circuit breaker (2) because by full molding the circuit breaker (2) will be enclosed by a dense mass (6) which hermetically closes the possibility that the gases will escape. The circuit breaker (2) has one or more openings (12) which are designed to emit the gases in the case of a short circuit, but because of the molding, these openings (12) will be sealed. In the illustrated embodiments, over the openings (12) there is arranged a membrane (13) that prevents the molding compound (6) to penetrate the security element (2) .

In the case of a short circuit and development of ionized gases with pressure, this membrane (13) could be pushed outward and create a pressure on the external elements which comprise the explosion protection element (14) and molding compound ( 6 ) .

The explosion protection element (14) is arranged in a protection volume () which is at least partly bounded by the molding compound (6), and has such a characteristic that it is compressed under pressure and will form a cavity (15) which will decrease the pressure and thereby prevent the fuse (2) from bursting into pieces, creating a danger for the personnel operating it.

In the case of a larger short-circuit, the explosion

protection element (14) will be further squeezed and finally release the gases to free air and thus relieve the pressure in the breaker (14) in a safe direction from the personnel who operate it. Further, the illustrated embodiments are described in somewhat greater detail.

An explosion protection element (14) is typically designed so that it can be arranged close to the protection component (2) where this has openings (12) to release gas in the case of a short circuit. Alternatively, there may be multiple explosion protection elements. In the present embodiment, explosion protection element (14) is long and has a cross-section as illustrated in Figures 7C, 8C and 9C. The explosion protection element may also have other shapes than those illustrated in these figures. The explosion protection element (14) typically has such a shape that it may contribute to form a cavity (15) by said one or more openings (12). Furthermore, the element (14) typically is arranged such that, by the outer side of the molded component (1), it mainly is covered by layer of molding compound (6) . The element (14) can however be arranged with a protruding part (16) adapted to protrude through said layer of molding compound (6) . The figures 7C, 8C and 9C illustrate three possible states of the safety devices in the case of short circuit in the fuse (2) . The figures 7B and 7C show the molded protection component (1) in a normal working position where there either has not been any explosion or possibly an explosion of such magnitude that the explosion protection element (14) is not compressed. The molded protection component (1) thus maintains its security function and can be reused.

The figures 8B and 8C illustrate a second state where there has been an explosion and where the explosion protection element (14) is compressed so that the volume (15) for receiving the ionized gas is increased compared to the original volume. Said compression is however not permanent, but elastic in the sense that the explosion protection element (14) will regain its original shape when the pressure drops to normal. As with the first state, also here the protection component (1) could be reused.

The figures 9B and 9C illustrate a third state in which there has been a short circuit, and where the explosion protection element (14) is compressed so that the volume (15) for receiving the ionized gas is increased compared to the original volume. Said compression is permanent, plastic, in the sense that the explosion protection element (14) will not regain its original shape when pressure drops to normal.

Furthermore, parts of the explosion protection element (14) by said protruding part (16), are deformed to such an extent that the ionized gas flows right out of the molded protection component (1) . In addition, the explosion protection element (14) may be shifted relative to the surrounding molding compound (6), and in the case of a powerful short-circuit the whole or parts of the explosion protection element (14) could be pushed completely out of the molded component (1) . Unlike the two above-mentioned states, the protection component will here be permanently damaged and can not be reused.

In addition to its main function which is to increase safety in the case of short-circuit, the explosion protection element (14) also has a sealing function. It must therefore be fully or partially enclosed in molding compound (6) , and be

dimensioned for the relevant pressure from the outside.

The figures 7C, 8C and 9C show an enlarged, longitudinal cross-section of the safety devices for emission (handling) ionized gases which are highlighted at various phases of the discharge process. The invention further relates to a method for handling ionized gases formed in the case of short circuit in molded electrical protection component (1) where the molded protection component (1) is the molded protection component of such a type as described above.

The method for handling ionized gases comprises emission of expanding ionized gas formed in the case of the short circuit, out through openings (12) in the protection component, and to receive the ionized gas which is emitted through the openings (12), in a protection volume arranged by said openings (12 ), where the protection volume is at least partly limited by molding compound (6) . Furthermore, the method may comprise reducing pressure in the molded protection component (1) by the gas emitted through the openings (12) contributing to elastically compress a material that is arranged in the protection volume, and then possibly reduce the pressure in the molded protection component (1) by the gas emitted through the openings (12) helping to plastically compress a material which is arranged in the protection volume.

Finally, the method may comprise reducing pressure in the molded protection component (1) by the gas emitted through the openings (12) helping to permanently deform the material which is arranged in the protection volume to such an extent that parts of the gas is allowed to escape out of the molded component (1) .

Molding

The molding compound (6) may be one- or two-component . One- component molding compound (such as e.g. thermoplastics) is liguid at relatively high temperatures, while two-component molding compound (like e.g. epoxy, polyurethane, silicone and / or polyester) is liquid at the mixing of the two components and then cured. The molding compound may also be of other categories such as e.g. one-component glue or paint. The properties of the molding compound. The molding compound (6) in liquid / viscous state is arranged in the volume between the mold (7) and protection component to be molded. The molding compound (6) shall not normally be allowed to penetrate inside the protection component where it can be an obstacle to the mechanical operation of the equipment. Therefore, it may occasionally be necessary before molding to seal any openings in the protective mechanical component using sealants such as membrane, tape or similar.

Since these are standardized modular products that have not previously been molded, it is necessary to ensure that the molding compound does not enter into the products when filling the molding compound. This may be done by a shape molded 2- piece silicone or natural rubber cap is threaded over the product. First, the base part is pulled up to where the screw connections are arranged. The cables are then inserted through this to be fixed by the connection terminals. Then the upper part consisting of a transparent TPE plastic, is pulled down to the cables. The natural rubber hood is threaded over the TPE part and overlaps the lower part. The natural rubber hood can for example be about 20% smaller than the product over which it is pulled. This is to ensure a good sealing around the product and prevent air-filled spaces, and at the same time ensure a good sealing around the overlap.

Molding should be done in a dry environment to prevent that moisture that can condense, is locked in the molded solution. An alternative solution is that a gas that is adapted to prevent condensation, is closed in the automatic circuit breaker by molding.

Fasteners

Fastener arrangements e.g. in the form of a wall mount for a molded automatic circuit breaker, can be attached to said automatic circuit breaker by parts of the fastener being molded into the molding compound.

Systems

Many different types of electrical system solutions may comprise molded, electrical protection component. The system solutions may comprise one or more molded devices, or one or more other electrical devices, and possibly other devices. The molded devices will most typically be molded separately, but more than one device can be part of an integrated, molded subsystem. An example of a relatively simple system solution may comprise a combination of an automatic circuit breaker and an outlet. Such a system solution is appropriate for many applications such as connection to the power network in port for leisure boats, or for connection of a caravan or outlet for charging of battery for electric vehicles. Applications

In general, the invention is applied in various types of electrical installations both for industrial and private use, and both military and civilian. Application is for example relevant in connection with food processing, pulp and paper industry, the railway, car washes, road lighting, recreational boats, commercial boats, caravans, machinery, tools, power outlets, distribution boards and the like.

A relevant application of molded protection components in corrosive environments such as in connection with pulp industry. Since circuit breaker material can be installed in the corrosive environment close to the relevant machines, one does not need to pull this material out of that environment, which can provide improved positioning relative to the rest of the technical system, which further can mean simpler solutions and lower procurement costs . Alternatively one could have used boxes according to prior art with a high degree of

encapsulation, but these would result in both more complex and more expensive solutions.

A particularly relevant application of the invention, is the use of a molded automatic circuit breaker in light posts. In earlier times there was no requirement for 2-pole break at drop out in light posts, and melting fuses were applied.

Requirements for 2-pole break combined with a need for a high degree of encapsulation, gives need for a molded automatic circuit breaker. The cable to the luminaires is typically 6-10 m long, while the cable to the supply normally will be shorter (for example about 50 cm) . The molded automatic circuit breaker may be in accordance with one of the embodiments described above.

Claims

1. Molded electrical component, where the component

comprises manual control devices and at least one electrical connection device (5), and encapsulation devices suited to protect the component against intrusion of solid objects and fluids, where the encapsulation devices further comprise molding compound (6) which surrounds parts of the component to help achieving an enhanced degree of encapsulation,

characterized in that

- the molded electrical component comprises a modular

electrical protection component in the form of a power circuit breaker, earth leakage circuit breaker, automatic circuit breaker or combined automatic circuit breaker;

- the protection component comprises openings arranged to permit emission of expanding ionized gas that is formed in the case of short-circuit currents in the protection component, so that the maximum pressure in the protection component is reduced;

- the molded component comprises safety devices for the handling of the ionized gas;

- the safety devices comprise a safety volume arranged by the openings in the protection component, and where the

encapsulation devices further comprise sealants to seal the openings so that it helps prevent the molding compound from penetrating the protection component, where the protection volume is at least partly limited by the molding compound, and an explosion protection element, where the explosion

protection element is arranged in the protection volume; and - where the safety devices are arranged for stepwise handling of the emission, where the explosion protection element comprises a material that is suited to deform when subjected to external pressure, and where the material is designed so that with increasing pressure it:

- first is compressed elastically;

- then is compressed plastically, and

- finally is deformed permanently to such a degree that the gas is allowed to be released out of the molded component.

2. Molded electrical component according to claim 1, where the material that is suited to deform comprises closed cells.

3. Molded electrical component according to claim 2, where the material that is suited to deform comprises polyurethane foam, soft plastic, rubber or other deformable materials.

4. Molded electrical component according to one of claims 1 to 3, where the sealants comprise one or more membrane elements arranged tightly enclosing parts of said protection component so that the arrangement is adapted to help prevent molding compound from entering the protection component.

5. Molded electrical component according to claim 4, where one or more membrane elements are also arranged to help protect the component against the ingress of dust, liquid, gas, steam and other fluids.

6. Molded electrical component according to claim 4 or 5, where the encapsulation devices comprise a second membrane, where the second membrane is arranged to permit operation of the manual control devices, while the membrane encloses adjacent parts of the protection component, while the first membrane is adapted to enclose parts of the protection component at the opposite side of this, and where the two membranes are adapted to overlap in order to protect the whole protection component.

7. Molded electrical component according to one of claims 4 to 6, where at least one membrane element is arranged to help seal against ingress of molding compound when introducing cables .

8. Molded electrical component according to one of claims 4 to 7, where the molding compound contributes to secure/lock end elements such that sealing of house around contacts is improved.

9. Method for handling ionized gases formed in the case of short circuit in molded, electrical protection component, where said component comprises manual control devices and at least one electrical connection device and encapsulation devices suited to protect the component against ingress of solid objects and fluids, where the encapsulation devices further comprise molding compound (6) enclosing parts of the component to contribute to achieve an improved degree of encapsulation, where the protection component further

comprises openings arranged to allow releasing expanding ionized gas that is formed in the case of short circuit currents in the protection component, and where the

encapsulation devices further comprise sealants to seal the openings so that it contributes to prevent the molding compound from penetrating the protection component, comprising the following steps:

- releasing expanding ionized gas formed in the case of the short circuit out through the openings in the protection component ;

characterized by the following further steps: - to receive the ionized gas which is emitted through the openings, in a protection volume arranged by said openings, where the protection volume is at least partly bounded by molding compound.

10. Method according to claim 9, further comprising the following steps:

- to reduce pressure in the molded protection component by the gas emitted through the openings contributing to elastically compress a material arranged in the protection volume.

11. Method according to claim 9 or 10, further comprising the following steps:

- to reduce pressure in the molded protection component by the gas emitted through the openings contributing to plastically compress a material which is arranged in the protection volume .

12. Method according to one of claims 9 to 11, further comprising the following steps:

- to reduce pressure in the molded protection component by the gas emitted through the openings contributing to permanently deform the material which is arranged in the protection volume to such an extent that parts of the gas is allowed to be released out of the molded component.