GB2443723A

GB2443723A - A switchgear cabinet and a cooling device

Info

Publication number: GB2443723A
Application number: GB0721634A
Authority: GB
Inventors: Andreas Muller
Original assignee: Rittal GmbH and Co KG
Current assignee: Rittal GmbH and Co KG
Priority date: 2006-11-03
Filing date: 2007-11-05
Publication date: 2008-05-14
Anticipated expiration: 2027-11-05
Also published as: GB0721634D0; GB2443723B; DE102006051904A1

Abstract

A switchgear cabinet 10 has a cooling device 12 which forms a closed internal cooling circuit not in direct fluid communication with an associated external cooling circuit. The cooling device 12 is mounted in or on a side face 16 of the switchgear cabinet and is connected to the cabinet's interior by means of an air inlet 18 and an exhaust opening 20. The cooling device includes a receiving chamber 22 in which at least one internal heat exchanger 24 is accommodated. The receiving chamber has a fan arrangement 28a, 28b to circulate cooling air in the interior of the cabinet. The internal heat exchanger 24 transfers the heat removed from the air flow from the interior space of the switchgear cabinet to a closed internal cooling circuit (30, fig 2), on which cooling circuit there is disposed at least one heat transferring unit (32, fig 2) which removes heat from the internal cooling circuit 30 and transfers it to an external cooling circuit 34.The external cooling circuit is therefore not in fluid communication with the internal circuit, allowing the circuits to be disconnected from each other.

Description

AN ASSEMBLY INCLUDING A SWITCHGEAR

CABINET AND A COOLING DEVICE

The invention relates to an assembly including at least one cabinet, such as a switchgear cabinet, and a cooling device, wherein the cabinet includes a closed interior space, in which electric components can be accommodated. The cooling device is mounted in the region of a side face of the cabinet that is situated at right-angles relative to the front side and extends at least over a part of the height of the switchgear cabinet. The cooling device is connected to the interior space so as to conduct air by means of at least one air inlet and one exhaust opening. The cooling device includes a receiving chamber or compartment, in which at least one internal heat exchanger is accommodated, wherein the receiving chamber is divided at least in regions into two or more part-receMng chambers or compartments that are disposed vertically one above the other and in at least one of the part-receiving chambers there is accommodated a fan arrangement. In this case, the internal heat exchanger removes heat from the air flow from the intenor space of the switchgear cabinet.

DE 10 2004 008 460 B4 makes known a device arrangement of this kind, where the internal heat exchanger is connected to a flow line and a return line, by means of which a cooling medium is conveyed. The flow line and the return line, in this case, are directly connected to an external re-cooling system. An external re-cooling system of this type is disposed outside the switchgear cabinet. There is a direct fluid connection between the internal heat exchanger and the external re-cooling system which means that faults in the external re-cooling system also have a direct effect on the internal heat exchanger. For example, a leak in the external re-cooling system can result in the flow and return line, and consequently the entire cooling circuit, being emptied.

In addition, connecting the switchgear cabinet to the external re-cooling system is extremely costly, especially as the entire cooling circuit can only be filled with water once the flow and return lines have been connected. The cooling water pressure in the external re-cooling system, in this case, has to be adapted to the pressure requirements of the flow and the return line and of the internal heat exchanger. An adjustment of the temperature of the cooling air, which emerges into the interior of the switchgear cabinet, can only be effected in an unsatisfactory manner in the case of the said known device arrangement, especially as the refrigerating capacity depends directly on the external re-cooling system and its adjustment possibilities.

It is the object of the invention to create an assembly of the aforementioned type, where the operational reliability is increased.

This object of the invention is achieved through an assembly in accordance with the features of claim 1. Advantageous further developments are described respectively in the sub claims.

Accordingly, the internal heat exchanger transfers the heat removed from the air flow out of the interior space of the switchgear cabinet to a dosed internal cooling circuit that is associated with the cooling device. At least one heat transfer unit is disposed in the said internal cooling circuit, the said heat transfer unit removing heat from the internal cooling circuit and transferring it to an external cooling circuit.

The external cooling circuit, in this case, can also be an open cooling circuit, where, on the one hand, cool cooling fluid is supplied to the heat transferring unit and, on the other hand, in the heat transferring unit heated cooling fluid is conducted away by the heat transferring unit.

Consequently, two separate cooling circuits are provided according to the invention, between which there is no fluid connection. A fault in the external cooling circuit, consequently, has no direct effect on the filling level of the internal cooling circuit. The internal cooling circuit is closed and can be filled with the cooling medium when being produced.

A fluid cooling medium flows in the internal cooling circuit, the said fluid cooling medium removing heat from the internal heat exchanger and delivering it to the heat transferring unit. In this case, the fluid cooling medium flowing in the internal cooling circuit can be water. The internal heat exchanger is then in the form of an air/water heat exchanger that is designed as a lamellar heat exchanger.

The internal cooling circuit can define a return line and a flow line between the internal heat exchanger and the heat transferring unit. In this case, the internal heat exchanger can be supplied by the heat transferring unit with cooled cooling water via the return line, whereas the cooling water heated in the internal heat exchanger can be conducted away by means of the flow line in its turn to the heat transferring unit.

In order to detect the temperature of the cooling fluid in the internal cooling circuit, at least one temperature sensor can be disposed in the internal cooling circuit. More especially, the temperature of the cooling fluid in the return line and/or in the flow line can be detected by a temperature sensor being disposed in each return line or respectively in each flow line.

In order to convey the internal cooling medium in the internal cooling circuit, an internal pump device can be disposed in the internal cooling circuit.

In this case, the discharge of the internal pump device can be controlled in dependence on the temperature of the cooling fluid or respectively in dependence on the return and/or flow temperature. For this purpose, the temperature sensors can be connected to an electric control unit, which, in its turn, is connected to the pump device.

A control valve device can be disposed in a tine connection between the return line and the flow tine in order to bring the cooling medium in the return line and the cooling medium in the flow line together depending on the valve position and consequently to influence the flow or respectively return temperature in the internal cooling circuit. This means that the temperature of the cooling air is also directly influenced. In this case, the control valve device can be controlled in dependence on the return and/or flow temperature. For this purpose, the temperature sensors can be connected to an electric control unit, which, in its turn, is connected to the control valve device, which is electrically actuatable.

A fluid cooling medium can also flow in the external cooling circuit, the heat transferring unit being in the form of a plate heat exchanger in order to guarantee a particularly good heat transfer from the internal to the external cooling circuit. In this case, the fluid cooling medium flowing in the external cooling circuit can be water.

An external cooling unit can be disposed in the external cooling circuit, the said external cooling unit cooling down the heated water supplied to it by the heat-transfer unit. In this case, the external cooling unit can be in the form of a re-cooler, a water cooler or a cooling tower.

The part-receiving chambers formed in the cooling device can be closed by means of a cover on their side facing the cabinet, the cover forming the air inlet and the exhaust opening.

Each of the part-receiving chambers or compartments as separate structural units, can include an internal heat exchanger unit and at least one fan unit. This means that in a vertical arrangement as in the case of the part-receiving chambers, particularly effective heat transfer and consequently particularly effective cooling is possible.

In addition, the individual part-receMng chambers can each have their own internal cooling circuit. This makes it possible for a predetermined cooling air temperature to be set on the pump device or on the control valve device in each vertical arrangement of the part-receiving chambers.

Consequently, depending on the cooling requirement in the cabinet, the necessary cooling air temperature can be made available each time.

A respective heat transfer unit can be disposed in each internal cooling circuit, the said heat transfer unit removing heat from the internal cooling circuits and transferring it to the external cooling circuit. The heat incurred with this arrangement can be conducted away in a particularly good manner.

As an alternative to this, all or one part of the part-receiving chambers can also include a common internal heat exchanger. The expense and time spent on parts and construction is reduced by one heat transferring unit being used to dissipate the heat of several internal cooing circuits.

According to an advantageous development, the cooling device can be installed between two cabinets, it being possible in a selective manner to move the part-receiving chambers so that they are connected to the interior space of one or both cabinets so as to conduct air by means of air inlets and exhaust openings. This means that with a particularly space-saving arrangement, the simultaneous cooling of two cabinets is achieved.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: -Figure 1 is a perspective view from one side and above of a specific embodiment of an assembly according to the invention comprising a cooling device mounted on the side wall of a cabinet for electrical products; Figure 2 is a basic circuit diagram of the design of a cooling module of the cooling device shown in Figure 1; Figure 3 is a schematic side representation of another specific embodiment of a cooling device mounted on the side wall of a cabinet; Figure 4 is a top view and a section according to the line lV-lV in Figure 3 of the cooling device installed between two cabinets; Figure 5 is a basic circuit diagram of the cooling device shown in Figures 3 and 4, and Figure 6 is a basic circuit diagram of yet another specific embodiment of a cooling device.

Figure 1 shows a cooling device 12 with a rack. The cooling device 12 is mounted on a side face 16 of a cabinet 10 for electrical devices such as a switchgear cabinet that is situated normal relative to the front side 14 and extends over the entire height of the switchgear cabinet. The cabinet 10 includes a closed interior space, in which electric components (not shown) can be accommodated.

The rack of the cooling device 12 is assembled from twelve frame profiles 13a, 13b and 13c. The horizontal frame profiles 13a and 13b form a bottom and a top frame, in the corner regions of which the four vertical frame profiles 13c with identical cross-sections, are welded. The receiving compartment or chamber 22 surrounded by the rack is divided into three part-receiving compartments 26a, 26b, 26c by means of horizontal compartment bases 15. The part-receiving compartments 26a, 26b and 26c can be covered on both sides on the broad sides of the rack by means of lateral covers 52. The covers 52 each have an air inlet 18 and an exhaust opening 20. The front and rear narrow sides and the roof side of the rack are covered by suitable screens. The compartment bases 15 are secured to the vertical frame profiles 1 3c and each serve to receive a cooling module 21. In this case, each cooling module 21 is made up of two structural, units -one heat exchanger unit 23 and a fan unit 28.

The heat exchanger unit 23 has a heat exchanger housing 27, into which is inserted an internal air/water heat exchanger 24, which removes heat from the air flow from the interior space of the cabinet 10. The heat exchanger housing 27 has two outlet openings 29, which can be disposed in alignment with the exhaust opening 20 of the covers 52.

The fan unit 28 has a fan housing 31, which receives two fans 28a and 28b. The fan housing 31 is connected by means of its open sides to the air inlets 18 of the covers 52 so as to conduct air.

To mount the cooling module 21, the heat exchanger unit 23 is inserted into the associated part-receiving compartment 26a, 26b or 26c through the open front side of the rack between the two vertical frame profiles 1 3c on the compartment bottom 15 until the heat exchanger housing 27 contacts a stop member 53 on the covers 52 and the insertion movement is stopped. In the same way, the fan unit 28 is inserted into the part-receiving compartment 26a from the rear side of the rack on the compartment base 15, which serves as a sliding guide. The stop member 53 once again stops the insertion movement.

The fans 28a and 28b convey the air out of the interior of the switchgear cabinet 10 through the air inlet 18. The warm air flows through the internal heat exchanger 24, is cooled there and leaves the part-receiving chamber 26a through the exhaust opening 20 in the direction of the interior space of the cabinet 10.

Figure 2 is a schematic circuit diagram of the design of a cooling module 21, as can be used in a cooling device 12 as in Figure 1. The internal heat exchanger 24 is in the form of an air/water heat exchanger designed as a fin/lamellar heat exchanger and is connected to a closed internal cooling circuit 30 that is associated with the cooling device 12 or respectively the cooling module 21. The internal heat exchanger 24 transfers the heat removed from the air flow out of the interior space of the cabinet 10 to the internal cooling circuit 30. Cooling water flows in the internal cooling circuit 30, which cooling water receives heat from the internal heat exchanger 24. A heat transferring unit 32 is disposed in the inner cooling circuit 30, the said heat transferring unit, in its turn, removing heat from the internal cooling circuit and transferring it to an external cooling circuit 34 (not connected in Figure 1).

Each of the part-receiving compartment 26a, 26b and 26c shown in Figure 1, as separate structural units, can include an internal heat exchanger unit 24 and at least one fan unit 28a, 28b and also an internal cooling circuit 30.

A heat transferring unit 32 can be disposed in each of the internal cooling circuits 30, the said heat transferring unit removing heat from the respective internal cooling circuit 30 and transferring it to the external cooling circuit 34.

The internal cooling circuit 30 includes a return line 36 and a flow line 38 respectively between the internal heat exchanger 24 and the heat transferring unit 32. The internal heat exchanger 24 is supplied with cooled cooling water by the heat transferring unit 32 in the direction of the arrow A via the return line 36. The cooling water heated in the internal heat exchanger 24 is conducted away in the direction of the arrow B to the heat transferring unit 32 via the flow line 38.

An electrically operated internal pump device 44 is disposed in the internal cooling circuit 30 for conveying the cooling water. Temperature sensors 40 or respectively 42 are disposed respectively in the return line 36 and the flow line 38 for detecting the return and flow temperature of the cooling water. The discharge of the internal pump device 44 can be controlled in dependence on the return and/or the flow temperature of the cooling water. For this purpose, there is provided a control device (not shown), which is connected in a suitable manner, on the one hand, to the temperature sensors 40 and 42 and, on the other hand, to the pump device 44. If the discharge of the pump device 44 is increased within predetermined limits, that-is-to-say the flow speed of the cooling water is increased, more heat can be conducted out of the internal heat exchanger 24.

In the specific embodiment in Figure 2 the external cooling circuit 34 is not connected. Furthermore, the flow line and the return line of the heat transferring unit 32 have drip-free joinable and separable quick-release couplings 35a and 35b, by means of which the external cooling circuit 34 can be connected. A fluid cooling medium, for example water, normally flows in the external cooling circuit 34 to be connected.

The heat transfer unit 32 is in the form of a plate heat exchanger so as to achieve good heat transfer from cooling fluid to cooling fluid in the two separate cooling circuits 30 and 34.

Figure 3 is a schematic representation of another specific embodiment of a cooling device 12 that is mounted on the side waIl 16 of a switchgear cabinet 10. Similar to the specific embodiment in Figure 1, the receiving compartment 22 for the cooling device 12 is divided into three part-receiving chambers 26a, 26b and 26c that are disposed vertically one above the other.

In the direction of the vertical extension of the cooling device 12, an internal air/water heat exchanger 24 designed in the form of a fin/lamellar heat exchanger is disposed in the receiving chamber 22 and extends vertically I0 through the part-receMng compartment 26a, 26b and 26c. The result of this is that the air flows created in the three part-receiving compartment 26a, 26b and 26c are cooled by means of the one internal heat exchanger 24. The fans 28a and 28b disposed in each part-receiving compartment 26a, 26b and 26c convey the air out of the interior of the switchgear cabinet 10 through the air inlets 18. The warm air flows in each part-receiving chamber 26a, 26b and 26c through the one heat exchanger 24, is cooled there and leaves the respective part-receiving chamber 26a, 26b, 26c through the respective exhaust opening 20 in the direction of the interior space of the cabinet 10.

The heat exchanger 24 is connected to a closed internal cooling circuit (not shown in Figure 3), which is associated with the cooling device 12 and conveys cooling water. The internal heat exchanger 24 transfers the heat removed from the air flow out of the interior space of the cabinet 10 to the said internal cooling circuit. A heat exchanger 32 that is in the form of a plate heat exchanger is disposed in the inner cooling circuit, the said plate heat exchanger being disposed in the spectfic embodiment in Figure 3 on the bottom region of the cooling device 12 at the lower end of the internal heat exchanger 24. The heat transfer unit 32 extends vertically relative to the internal heat exchanger.

The heat transfer unit 32 removes heat from the internal cooling circuit and transfers the said heat to an external cooling circuit (not shown in Figure 3).

Figure 4 is a section on the line lV-lV of Figure 3 viewed from above of the cooling device 12 that is installed between two switchgear cabinets 10 and 11. The cabinets 10 and 11 are conventionally designed and include a rack that is clad with wall elements and a door at the front. The cooling deJice 12 replaces the wall element on the sides of the switchgear cabinet that face each other. I'

The fans 28a and 28b convey the air out of the interior of the switchgear cabinets 10 and 11 through the air inlets 18 mounted on both sides of the cooling device 12. The warm air flows through the internal heat exchanger 24, is cooled there and leaves the part-receiving chamber 26a shown in Figure 4 through the exhaust openings 20 mounted on both sides of the cooling device 12 in the direction of the respective internal chambers of the switchgear cabinets 10 and 11.

The internal air/water heat exchanger 24 is divided into two in its longitudinal extension, each part 24a and 24b being fully functional in its own right, in order, for example, to maintain operation in the event of servicing if one of the heat exchangers 24a or 24b fails. The heat transfer unit 32 connected to the internal cooling circuit is disposed underneath the internal heat exchanger 24 on the right-hand side of the cooling device 12 as shown in Figure 4.

The cooling device 12 illustrated in Figure 4 can also be used on its own with just one cabinet 10. The side of the cooling device remote from the cabinet 10 is then closed by a side wall.

Figure 5 is a schematic circuit diagram of the cooling device 12 shown in Figures 3 and 4. The internal heat exchanger 24 is in the form of a fin/lamellar heat exchanger and is connected to a closed internal cooling circuit 30 that is associated with the cooling device 12.

The internal heat exchanger 24 transfers the heat removed from the air flow out of the interior space of the cabinet 10 to the internal cooling circuit 30.

Cooling water flows in the internal cooling circuit 30, the said cooling water receiving heat from the internal heat exchanger 24. A heat transfer unit 32 is disposed in the inner cooling circuit 30, the said heat transfer unit 32 removing, in its turn, heat from the internal cooling circuit 30 and transferring it to an external cooling circuit 34.

An electrically operated internal pump device 44 is disposed in the internal cooling circuit 30 for conveying the cooling water. Temperature sensors 40 or respectively 42 are disposed respectively in the return line 36 and the flow line 38 for detecting the return or flow temperature of the cooling water. The discharge of the internal pump device 44 can be controlled in dependence on the return and/or flow temperature of the cooling water.

The pump device can be formed by two pump units (not shown) that are disposed in parallel line branches, the second pump unit maintaining the conveying operation if the first pump unit fails.

A fluid cooling medium, for example water, normally flows in the external cooling circuit 34. The heat transfer unit 32 is in the form of a plate heat exchanger in order to achieve a good heat transfer of cooling fluid to cooling fluid in the two separate cooling circuits 30 and 34.

A cooling unit 50 is disposed in the external cooling circuit 34, the said cooling unit cooling the heated water supplied to it by the heat transferring unit 32 in the external cooling circuit 32. The cooling unit 50, in this case, can be in the form of a re-cooler, water cooler or cooling tower also with a pump incorporated therein (not shown) for conveying the coolant in the external cooling circuit.

As an alternative to this, the external cooling circuit 34 can also be open, that-is-to-say not in the form of a closed cooling circuit but, for example, in the form of a cooling circuit supplied with fresh water.

Figure 5 illustrates the external cooling circuit 34 divided visually into two parts by a vertically extending, broken line 58. The part of the external cooling circuit 34 located to the left of the broken line 58 is accommodated within the switchgear cabinet 10, whereas the part of the external cooling circuit 34 located to the right of the broken line is disposed outside the switchgear cabinet 10 in the outer chamber 60. More especially, the cooling unit 50 is also disposed in the outer chamber 60.

Figure 6 is a schematic circuit diagram of yet another specific embodiment of a cooling device 12. The specific embodiment in Figure 6 differs from the specific embodiment in Figure 5 only decisively in that a control valve device 48 is disposed in a horizontal line connection 46 between the return line 36 and the flow line 38. The remaining components correspond extensively to the components described by way of Figure 5 and have the same references.

Temperature sensors 40 or respectively 42 are disposed respectively in the return line 36 and the flow line 38 for detecting the return or respectively flow temperature of the cooling water. The control valve device 48 is electrically actuatable and can be controlled in dependence on the return and/or flow temperature of the cooling water. For this purpose, there is provided a control device (not shown) which is connected in a suitable manner, on the one hand, to the temperature sensors 40 and 42 and, on the other hand, to the pump device 44.

Claims

1. An assembly including at least one cabinet (10, 11) such as a switchgear cabinet, and a cooling device (12), wherein the cabinet (10, 11) includes a closed interior space, in which electrical components can be accommodated, wherein the cooling device (12) is mounted in the region of a side face (16) of the cabinet (10, 11) that is situated or extends vertically or transversely relative to the front side (14) and extends at least over a part of the height of the switchgear cabinet and is connected to the interior space so as to conduct air by means of at least one air inlet (18) and at least one exhaust opening (20), wherein the cooling device (12) includes a receiving chamber (22), in which at least one internal heat exchanger (24) is accommodated, wherein the receiving chamber or compartment (22) is divided at least in regions into two or more part-receiving chambers or compartments (26a, 26b, 26c) that are disposed vertically one above the other and in at least one of the part-receiving chambers or compartments (26a, 26b, 26c) there is disposed a fan arrangement (28a, 28b), and wherein the internal heat exchanger (24) removes heat from the air flow from the interior space of the cabinet (10, 11), charactensed in that the internal heat exchanger (24) transfers the heat, removed from the air flow from the interior space of the cabinet (10, 11), to a closed internal cooling circuit (30) that is associated with the cooling device (12), on which cooling circuit there is disposed at least one heat transfer unit (32), which removes heat from the internal cooling circuit (30) and transfers it to an external cooling circuit (34).

2. An assembly according to claim 1, charactensed in that a fluid cooling medium flows in the internal cooling circuit (30), the said fluid cooling medium receiving heat from the internal heat exchanger (24) and emitting it to the heat transferring unit (32).

3. An assembly according to claim 1 or 2, characterised in that the flUid cooling medium flowing in the internal cooling circuit (30) is water and the internal heat exchanger (24) is in the form of an air/water heat exchanger that is designed as a lamellar heat exchanger.

4. An assembly according to one of claims I to 3, characterised in that the internal cooling circuit (30) between the internal heat exchanger (24) and the heat transferring unit (32) defines a return line (36) and a flow line (38) respectively; wherein the internal heat exchanger (24) is supplied with coated cooling water (arrow A) from the heat transferring unit (32) via the return line (36) and the cooling water (arrow B) heated in the internal heat exchanger (24) is conducted away to the heat transferring unit (32) via the flow line (38).

5. An assembly according to one of claims I to 4, characterised in that at least one temperature sensor (40, 42) is disposed in the internal cooling circuit (30)10 detect the temperature of the cooling fluid.

6. An assembly according to claim 4, characterised in that a temperature sensor (40, 42) is disposed respectively in the return line (36) and/or the flow tine (38) to detect the return or respectively the flow temperature.

7. An assembly according to one of claims 1 to 6, charactensed in that an internal pump device (44) is disposed in the internal cooling circuit (30) for conveying the internal cooling medium.

8. An assembly according to one of claims 5 to 7, characterised in that the discharge of the internal pump device (44) is controllable in dependence on the temperature of the cooling fluid or respectively in dependence on the return and/or flow temperature.

9. An assembly according to one of claims 1 to 8, characterised in that a control valve device (48) is disposed in a line connection (46) between the return line (36) and the flow line (38), the said control valve device being controllable in dependence on the return and/or flow temperature.

10. An assembly according to one of claims I to 9, characterised in that a fluid cooling medium flows in the external cooling circuit and the heat transferring unit is in the form of a plate heat exchanger.

11.An assembly according to one of claims 1 to 10, characterised in that the fluid cooling medium flowing in the external cooling circuit (34) is water, and in that a cooling unit (50) is disposed in the external cooling circuit (34), the said cooling unit cooling down the heated water supplied to it by the heat transferring unit (32).

12.An assembly according to one of claims I to 11, characterised in that the part-receiving chambers (26a, 26b, 26c) are closed on their side facing the cabinet by means of a cover (52), and in that the cover (52) forms the air inlet (18) and the exhaust opening (20).

13. An assembly according to one of claims I to 12, characterised in that the part-receiving chambers (26a, 26b, 26c), as separate components, each include an internal heat exchanger unit (24) and at least one fan unit (28a, 28b).

14.An assembly according to one of claims I to 13, characterised in that the part-receiving chambers (26a, 26b, 26c) each include an internal cooling circuit (30).

15. An assembly according to one of claims I to 13, charactensed in that the part-receiving chambers (26a, 26b, 26c) include a common internal heat exchanger (24).

16. An assembly according to claim 14 or 15, charactensed in that a heat transfer unit (32) is disposed in each internal cooling circuit (30), the said heat transfer unit removing heat from the internal cooling circuits (30) and transferring it to the external cooling circuit (34).

17. An assembly according to one of claims 1 to 16, characterised in that the cooling device (12) is installed between two cabinets (10, 11), and in that the part-receiving chambers (26a, 26b, 26c) can be moved in a selective manner into connection with the interior space of one or both cabinets (10, 11) so as to conduct air via air inlets (18) and exhaust openings (20).

18. An assembly including at least one cabinet or like electrical component housing substantially as herein described with reference to any of the embodiments of Fig. I and 2 or modified in Figs. 3 and 4 or in Fig. 5 as possibly modified by Fig. 6.