GB2497357A - Equipment, such as ventilation fans, with removable mains PSU mounted in fan housing or externally to comply with safety extra low voltage SELV standards - Google Patents

Abstract

Equipment, such as an extractor fan for ventilation of rooms that may be wet, such as bathrooms, has a power supply (PS) designed to be mountable internally or externally to the equipment as a module that may comprise a PCB and base mounting plate. The power supply converts a high input voltage, such as a mains AC supply to a low output voltage, such as a safer 24v or 12v DC supply for the fan or other equipment. When removed, the PS may allow the fan etc. to be located in domestic areas with designated restrictions requiring safer lower voltages, the PS then located remotely from the area and preferably in a separate remote housing (190) as figure 3 shows. The PS is mounted in a removable manner on a chassis carrying the extractor fan and within a fan housing (110,120); the PS is shown mounted in figure 1. Figure 4 has a clearer view of high voltage mains connection means 160, 200 and low voltage output connection means 164, 202; also shown are mounting holes (174) for the fan chassis and alternative mounting holes 180 for separate housing (190 fig 3). The chassis may include a second low voltage connector 166 for use when the PS is remotely located and connected to the fan etc. by cables.

Description

Equipment with removable power supply The invention relates to electrical equipment suitable for installation in areas where electrical power supply is restricted, e.g. for reasons of safety. For example, certain buildings regulations have to be met for installation of electrical equipment in bathrooms or other wet rooms. In particular, the invention is applicable to domestic ventilation equipment which may be installed in a bathroom or similar area.

The mains electricity supply in most buildings is relatively high, e.g. 240 V in the UK. The provision of electrical outlets in bathrooms or similar areas is restricted so as to avoid or minimise the risk of water coming into contact with the electrical outlets. In bathrooms, the UK building regulations identify specific zones in a bathroom in which different rules apply, e.g. the zone 2.25 metres directly above a bath has more stringent regulations than regions within 0.6 metres to the side of the bath, which in turn are more stringent than areas outside of both those zones.

In general, the provision of mains electricity into a bathroom is restricted to areas sufficiently far from the main water sources (such as baths and showers). In older properties, e.g. properties with old fuse boards rather than modern RCD boards, the regulations are also stricter.

Many electrical devices designed for use in bathrooms are therefore designed to operate at low voltage, for example 24 V. For example, ventilation equipment such as extractor fans can be designed to operate at low voltage. For such devices, a transformer is required to convert the building's mains supply (e.g. at 240 V) down to the low voltage supply (e.g. 24 V) required for the equipment. Depending on the particular circumstances at the installation premises, the transformer may be located inside the target room, e.g. inside the equipment itself, or it may have to be located outside the room so that only the low voltage supply is fed into the target room. The transformer is part of a power supply unit.

It is typically more convenient to provide the power supply as part of the equipment where possible. The end user (or equipment installer) then only has to make a single connection to connect the mains power to the equipment.

Where an external power supply is necessary, the power supply is typically supplied as a separate unit and two connections are required. The installer first connects the mains power to the power supply outside the target room and then connects the power supply output to the equipment inside the target room.

The installer may often not know which type of arrangement is required before arriving at the premises and may therefore either find that he/she does not have the right equipment to install or has to carry both types of equipment. For simplicity, the installer may just use the equipment with a separate power supply, but if it is not required then the installation is not as quick, simple and neat as it could have been.

According to the present invention there is provided equipment with a power supply designed to be mountable internally or externally, the power supply converting a high input voltage to a low output voltage for the equipment.

The ability to change the configuration of the fan allows the same fan to be installed in different situations. For example the same fan can be installed with the power supply mounted internally it the regulations permit such installation. This is neater and requires fewer connections and less work on the part of the installer. However, if the regulations do not permit high voltage supply into the desired installation area then the power supply is removable and can be installed externally to the equipment and outside the restricted area. With this configuration only low voltage power is supplied to the restricted area.

The external power supply configuration is necessary for the equipment to comply with the SELV (Safety Extra Low Voltage) standard. Therefore if a SELV installation is required, the equipment can be configured with the power supply mounted externally.

With equipment according to the invention, the installer can stock and carry a single piece of equipment which can be adapted at the premises according to the requirements. Regardless of the end user's set up, the same piece of equipment can be installed in the preferred way according to the regulations.

The power supply preferably comprises a high voltage input connector and a low voltage output connector and preferably the equipment comprises a low voltage input connector. The high voltage connector provides for connection of the electricity mains supply. The low voltage connectors are for transfer of the electricity from the power supply to the equipment. As the power supply is removable, it is preferable to allow easy separation of the electrical connection between the power supply and the equipment.

The three connectors may be sufficient in some equipment to provide all the necessary connections. From mains to power supply and from power supply to equipment. However, in some particularly small and compact equipment, space inside the equipment is limited. Therefore it is desirable to minimise the size of any internal power supply connections inside the equipment. In preferred embodiments, the power supply comprises two low voltage output connectors and one of the low voltage output connectors is a smaller format than the other low voltage output connector. The equipment may comprise two low voltage input connectors and one low voltage input connector may be a smaller connector format than the other low voltage input connector. The smaller connector format is used when the power supply is mounted internally. This is the configuration in which space most needs to be conserved as the power supply itself occupies a significant volume within the equipment. As the connection in this configuration is all internal to the equipment and the length of wire required for making the connection is known in advance, the connection can be made via small leads and small pre-wired connectors, e.g. plug and socket connectors. The equipment side of the connection can be made by a soldered connection direct to the relevant control board, thus minimising space usage. On the other hand, with the power supply in the remote configuration, the position of the power supply relative to the equipment is not known at the time of manufacture, but is only known at the time of installation.

Thus the necessary wiring and the necessary connections have to be made on site.

For ease of installation, these connections are typically made be chocolate block type connectors, e.g. screw-type connectors where the bared wire is inserted into a hole in the connector and fixed in place with a set screw. Such connectors are generally larger than pre-wired plug/socket connectors in order to allow quick and simple connection with standard tools.

When the power supply is to be mounted in an external configuration, the internal (i.e. inside the equipment) low voltage connector is also preferably of the larger format for easy connection by the installer. This connection is not required when *the power supply is mounted internally as the alternative small format low voltage connections are used instead. Therefore in some preferred embodiments, when the power supply is mounted internally, it is mounted over the low voltage input connector. This arrangement makes good use of space without interfering with the connectors which are required for internal mounting. If the equipment has both large and small low voltage input connectors, the power supply is preferably mounted over the larger low voltage input connector.

The two alternative low voltage connection paths may be formed as simple electrical alternatives, i.e. both low voltage equipment connectors can be connected to the same points on the equipment control board and the two low voltage connectors on the power supply can be connected to the same nodes on the power supply. Only one pair of connectors is used at one time.

As mentioned above, preferably the small format low voltage input connector and output connector are plug and socket connectors as these can be manufactured smaller and provide for easier connection during equipment assembly if the power supply is to be supplied in the internal mounting configuration. Also as discussed above, the large format input connector and output connector are preferably screw-type connectors such as chocolate block connectors or set-screw type connectors.

The power supply typically comprises a PCB with some circuitry and components mounted thereon. Inside the equipment, this can simply be mounted to the equipment housing in some fashion (e.g. by adhesive, clips or screws). However if the power supply (i.e. the PCB) is to be mountable externally, it needs to be housed in a housing so as to protect the electrical circuits and components. The power supply therefore needs to be removably attached to the equipment (e.g. by clips or screws). The power then needs be mounted in the external housing. In preferred embodiments, the power supply is mounted on a base plate and the base plate is removably attachable to the equipment for internal mounting. This arrangement allows the power supply to be removably attachable to the equipment for internal mounting. For the external configuration, the base plate acts as part of the housing.

It is then not necessary to mount the power supply to the housing, but simply to fix a housing cover member onto the base plate to form a complete housing. The base plate takes up space inside the equipment, but it also acts as a support tray to hold the power supply firmly in place and to make it easier to handle the power supply without handling the components thereof when removing it from the equipment.

The invention applies to many types of equipment which may be used with either a separated or non-separated power supply. However, in preferred embodiments of the invention the equipment is domestic ventilation equipment. Such ventilation equipment can be mounted in different locations within a building. For example, the same fan may be used in a kitchen or in a bathroom. The regulations for these locations vary. For example, it may be necessary to use a separated power supply for a bathroom installation, but the same fan unit could be installed in a kitchen with the power supply mounted internally of the fan unit.

In some embodiments, the invention may be used in positive input ventilation (PIV) equipment or in heat exchange systems which draw air in from outside. In other embodiments, the equipment may be an extractor fan for the purpose of venting air f.rom a space (e.g. one room or the whole house). In some preferred embodiments the equipment is an extractor fan suitable for installation in a bathroom or similar.

As mentioned above, the same fan may also be suitable for installation in other places such as a kitchen.

The invention also extends to a kit comprising equipment as described above and an external housing in which the power supply can be mounted for the external mounting configuration. Preferably the kit comprises equipment as discussed aboye with power supply on a base plate and an external housing part designed to be mated with the base plate so as to enclose the power supply for the external mounting configuration.

Preferred embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which: Figure 1 shows an exploded view of a domestic extractor fan with a removable power supply in the internally mounted position; Figure 2 shows an exploded view similar to Figure 1 but with the power supply removed from the main fan body: Figure 3 shows an exploded view of the removable power supply of Figures 1 and 2 with a power supply housing part; Figure 4 is a plan view of a power supply tray and PGB; and Figures 5 and 6 are plan views of a main body part of a fan respectively with and without the removable power supply mounted.

An exploded view of a domestic extractor fan 100 is shown in Figure 1. The fan includes a front housing part 110 with a grille 120 which opens and closes away from the housing part 110 to control the air intake of the fan and a main fan body 130 including the impeller 140, motor (not shown) and control circuits (not shown).

The fan 100 also includes a power supply 135 which converts a high voltage electricity supply such as a domestic mains supply at e.g. 240 V to a low voltage supply for the fan motor and controls. The power supply 135 is removable in that it can be mounted inside the fan 100 or it can be mounted separately from the fan 100 to comply with building and/or wiring regulations.

In Figure 1 the power supply 135 is mounted in the internal configuration. The power supply 135 is mounted to the main fan body 130 by fixing means, e.g. screws 175 (shown in Figure 2).

Figure 2 is similar to Figure 1 but shows the power supply 135 removed from the fan main body 130.

The power supply 135 comprises a printed circuit board 170 mounted to a base plate 150 in the form of a tray by fixing means, e.g. screws 177. The power supply comprises a high voltage input connector 160. When the fan is installed, the installer connects the buildings mains electricity supply to the high voltage input connector 160. A cable clamp 200 is associated with the connector 160. The connector 160 has live, neutral, earth and switch live connections.

The power supply 135 also comprises a two low voltage output connectors 162, 164. These two connectors are alternatives for connecting the low voltage output of the power supply 135 to the electronics in the fan main body 130. The two connectors are a small format low voltage output connector 162 and a large format output connector 164.

The small format connector 162 is socket into which a corresponding plug (not shown) can be fitted. To connect the electrical connection via the small format connector 162, a small cable (not shown) with an appropriate plug is plugged into the small format connector 162. The other end of the cable can either be connected to the fan electronics by another plug/socket connection or it can be directly soldered to the control PCB depending on which is more convenient with regard to the available space and the assembly process. With the power supply mounted inside the fan main body 130, the distance between the control PCB and the power supply is known from the fan design and thus the cable can be made of the appropriate length during manufacture and the connection to the power supply can be simply made or unmade by connecting or disconnecting the connector 162.

The large format connector 164 is a chocolate block type connector in which bared wires are inserted into the connector 164 and held in place via set screws which * screw down onto the bared wires to make and hold the electrical connection. Such connections are awkward to make and unmake as they require tools and involve * baring wires. However, when the power supply is to be mounted externally of the fan, e.g. due to the installation location of the fan and the corresponding wiring regulations, the distance of the power supply from the fan is not known until the time of installation. Therefore the connection cable between the power supply and the fan will have to be cut to length during installation. Therefore a simpler plug/socket type connection is not appropriate. A cable clamp 202 is associated with the large format low voltage output connector 164.

As the cable connecting the power supply 135 to the fan has to be cut to length during installation, a large format chocolate block type connector 166 is also provided on the fan main body 135. This connector allows the installer to make electrical connections during the installation process. The connector 166 connects the input power to the fan's control circuits in parallel with the cable connection from the small format connector 162, but only one connection is used at any given time, i.e. they are alternatives, one for internal mounting and one for external mounting.

The low voltage input connector 166 on the fan is positioned such that it lies underneath the power supply 135 when the power supply 135 is mounted internally.

This provides a space saving as the connector 166 is not required in this configuration, the low voltage power connection being made via small format connector 162 instead.

A cable clamp 204 is associated with low voltage input connector 166. The cable clamp 204 is positioned such that, in the external power supply configuration, the low voltage cable supplying power to the fan can enter the fan at the same point as the high voltage mains cable would enter for the internal power supply configuration, thus making good use of space and minimising the required number of cable entry points for the fan.

For the internal mounting configuration, screws 175 pass through holes 174 (shown in Figure 4) in the base plate 150 and attach to mounting points 176 on the fan main body (shown in Figure 2).

For the external mounting configuration, a power supply housing part 190 is provided to attach to base plate 150 so as to completely surround and house the power supply PCB 170. The housing part 190 contains air vents 194. The housing is mounted to the base plate 150 by releasable fixing means, e.g. screws 179 which pass through holes 192 in the housing part 190 and locate and fix in the mounting points 180 on the base plate 150. Four screws are used in this embodiment, as shown in Figure 3.

Figure 4 is a plan view of the base plate 150 and PCB 170 showing the various connectors 160, 162 and 164 on the power supply 135.

Figures 5 and 6 are plan views of the fan main body 130. Figure 5 shows the power supply 135 mounted to the main body 130 and Figure 6 shows the main body 130 with the power supply 135 removed, revealing the large format low voltage input connector 166 which lies beneath the power supply 135 in the internal mounting configuration.

The fan 100 is typically supplied with the power supply 135 in the internally mounted configuration and with the small format low voltage output connector 162 electrically connected via a cable to the control circuits of the fan. If the fan is to be installed with the power supply in an internally mounted configuration then the only connection required by the installer is the high voltage mains connection to the high voltage input connector 160. This makes the fan easy and quick to install.

If the fan is to be installed with the power supply in an externally mounted configuration, e.g. because of building or wiring regulations, or simply due to a preference of the end user or the installer, then the internal low voltage power cable is disconnected (unplugged) from the small low voltage output connector 162.

There are no bare wires on the disconnected cable, so the cable can simply lie inside the fan main body when it is not in use. The base plate 150 is then removed from the fan main body 130 by removing the releasable fixing means 175 and lifting out the base plate/tray 150 together with the PCB 170 mounted therein. Once the external mounting position of the power supply has been selected, the high voltage mains supply is connected to connector 160 in the same way as for the internal mounting configuration. To connect the power supply to the fan, a suitable length of cable is cut to connect the power supply 135 to the fan 100. One end of the cable is connected to the large format, chocolate-block type low voltage output connector 164 on the power supply 135 and the other end of the cable is connected to the large format, chocolate-block type low voltage input connector in the fan main body 130 which was revealed when the power supply 135 was removed from the main body 130.

The fan is provided as a kit of parts with the main fan 100 (main body, front housing, grille etc.), the removable power supply 135 (provided pre-connected in -10-the internal configuration), the external mounting housing part 190 and all relevant fixing means, 175, 179.

The removable power supply 135 thus provides great flexibility to the installer at the same time as making for a highly efficient installation process. For the internal mounting configuration only a single connection is required, but if an external mounting configuration is required, the removability allows the same fan unit to be used. The installer therefore does not need to know the details of the installation beforehand as a single fan unit is capable of installation in both scenarios.

Claims (1)

1. <claim-text>Claims 1. Equipment with a power supply designed to be mountable internally or externally, the power supply converting a high input voltage to a low output voltage for the equipment.</claim-text> <claim-text>2. Equipment as claimed in claim 1, wherein the power supply comprises a high voltage input connector and a low voltage output connector and wherein the equipment comprises a low voltage input connector.</claim-text> <claim-text>3. Equipment as claimed in claim 2, wherein the power supply comprises two low voltage output connectors, and wherein one of the low voltage output connectors is a smaller connector format than the other low voltage output connector.</claim-text> <claim-text>4. Equipment as claimed in claim 3, wherein the small format low voltage output connector is a plug or socket connector.</claim-text> <claim-text>5. Equipment as claimed in claim 3 or 4, wherein the equipment comprises two low voltage input connectors and wherein one low voltage input connector is a smaller connector format than the other low voltage input connector.</claim-text> <claim-text>6. Equipment as claimed in claim 5, wherein the large format input connector and output connector are screw-type connectors.</claim-text> <claim-text>7. Equipment as claimed in any preceding claim, wherein the equipment comprises a low voltage input connector and wherein when the power supply is mounted internally, it is mounted over the low voltage input connector.</claim-text> <claim-text>5. Equipment as claimed in any preceding claim, wherein the power supply is mounted on a base plate and wherein the base plate is removably attachable to the equipment for internal mounting.</claim-text> <claim-text>9. Equipment as claimed in any preceding claim, wherein the equipment is domestic ventilation equipment. -12-</claim-text> <claim-text>10. Equipment as claimed in any preceding claim, wherein the equipment is an extractor fan suitable for installation in a bathroom or similar.</claim-text> <claim-text>11. A kit comprising equipment as claimed in any preceding claim and an external housing in which the power supply can be mounted for the external mounting configuration.</claim-text> <claim-text>12. A kit comprising equipment as claimed in claim 8, 9 or 10 and an external housing part designed to be mated with the base plate so as to enclose the power supply for the external mounting configuration.</claim-text>