GB2556229A

GB2556229A - Consumer unit fire protection apparatus

Info

Publication number: GB2556229A
Application number: GB1721123.6A
Authority: GB
Inventors: Perks John
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-09-01
Filing date: 2017-12-18
Publication date: 2018-05-23
Anticipated expiration: 2037-12-18
Also published as: GB2556229B; GB201714043D0; GB201721123D0

Abstract

A consumer unit fire protection apparatus (100) has a body defining a cable passage (122), the cable passage (122) having a first cable opening (118) and a second cable opening (120) for communication with a corresponding opening of a consumer unit (10) and a sealing material portion (104, 106) arranged to seal a fire within the consumer unit. The sealing material in one embodiment is a non-intumescent fire resistant material, such as a fire-resistant foam which is applied as a liquid and solidifies to form a tight seal. In a further embodiment the sealing material is a sheet of intumescent material within the cable passage, which expands on exposure to fire to seal the passage.

Description

(54) Title of the Invention: Consumer unit fire protection apparatus Abstract Title: Consumer unit fire protection apparatus (57) A consumer unit fire protection apparatus (100) has a body defining a cable passage (122), the cable passage (122) having a first cable opening (118) and a second cable opening (120) for communication with a corresponding opening of a consumer unit (10) and a sealing material portion (104, 106) arranged to seal a fire within the consumer unit. The sealing material in one embodiment is a non-intumescent fire resistant material, such as a fireresistant foam which is applied as a liquid and solidifies to form a tight seal. In a further embodiment the sealing material is a sheet of intumescent material within the cable passage, which expands on exposure to fire to seal the passage.

1/9

138

109

Fig. 1

2/9

118

Fig. 2

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122

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104 fig. 4

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118

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122

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114

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110

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200

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Fig. 14

Consumer unit fire protection apparatus

The present invention is concerned with a fire protection apparatus for an electrical consumer unit. More specifically, the present invention is concerned with an apparatus for the passage of electrical wires into a consumer unit, which apparatus is configured to seal the unit to reduce ingress of air, and reduce egress of flames in the event of a fire within the consumer unit.

Consumer units are well known in the art of domestic and commercial electrical installations. Consumer units are electrical distribution boards which receive a power supply and feed the supply to a plurality of subsidiary circuits in e.g. the home. Consumer units typically comprise a casing or housing containing a DIN rail onto which several circuit breakers, residual current devices or fuses are installed. At the time of writing, MCBs (miniature circuit breakers) have been surpassed by RCDs (residual current devices) which are designed to interrupt power to the subsidiary circuit in the event of a fault.

Until recently, consumer unit housings were constructed from a plastics material with one or more knock outs on the upper surface in use. These knock outs comprised typically circular portions of housing material surrounded by a frangible seam. They could therefore be removed or knocked out by the installer to enable electrical cables to be fed into the consumer unit housing.

Modern consumer unit housings are constructed from metal material, which offers greater resistance to fire. In improperly installed MCBs and RCDs, loose contacts can result in arcing. In the event that a spark initiates a fire within the unit, metal housings can contain the fire more effectively than their plastic predecessors.

The metal housings still feature knock-outs, but sealing must be provided to inhibit the ingress of air in a fire, and to contain the flames within the unit. Sealing is often achieved by using plastic gland components which fit into the holes left by the knock-outs. Each gland contains a rubber seal which seals around the cables.

There are several problems with this known approach.

Because many cables are often installed in any given consumer unit, several knock-outs must be used, requiring a plurality of glands. This is time consuming to install, and further the glands have a relatively high associated cost. Further, the glands are constructed from plastic and rubber materials which are not as resistant to fire as metal components.

It is an aim of the present invention to overcome, or at least mitigate, the aforementioned problems.

According to a first aspect of the invention there is provided a consumer unit fire protection apparatus comprising:

a body defining a cable passage, the cable passage having:

a first cable opening; and, a second cable opening for communication with a corresponding opening of a consumer unit;

at least one cable passing through the cable passage;

a non-intumescent fire resistant material portion sealing the passage, and surrounding the at least one cable a to inhibit ingress of air to thereby suppress fire within the consumer unit.

According to a second aspect of the invention there is provided a consumer unit fire protection apparatus comprising:

a body defining a cable passage, the cable passage having:

a first cable opening; and, a second cable opening for communication with a corresponding opening of a consumer unit; and, an intumescent material portion arranged to expand and to thereby constrict the opening in reaction to a fire within the consumer unit.

Advantageously, the present invention both provides passage for cables into the unit and reduces the risk of a fire increasing in size and spreading outside the consumer unit. Therefore the passage can be made larger than in the prior art, with less need for tight rubber seals / glands as in the event of a fire, the passage is closed by the sealing material.

According to the first aspect, the sealing material is a non-intumescent fire resistant foam or putty. The material is preferably one which can be applied into the passage in a liquid state and which subsequently solidifies. In this way, the material can be applied to surround the wires passing through the passage in use, and thereby form a tight seal around them.

According to the second aspect, the material may be an intumescent material which is applied in a first (unexpanded) condition proximate the passage. Upon exposure to heat (i.e. a fire), the intumescent material will expand to seal the passage and surround the wires.

An example apparatus according to the present invention will now be described with reference to the accompanying figures in which:

Figure 1 is a front view of a first apparatus according to the present invention assembled with a consumer unit;

Figure 2 is a top perspective view of the apparatus and consumer unit of Figure 1;

Figure 3 is a front view of the apparatus of Figure 1 with a component removed;

Figure 4 is a side view of the apparatus of Figure 1 with a component removed;

Figure 5 is a detail view of the apparatus of Figure 1 with electrical wires installed therein;

Figure 6 is a detail view similar to Figure 3 with a component removed;

Figure 7 is a plan view of a part of the apparatus of Figure 1;

Figure 8 is a rear view of a component of a second apparatus in accordance with the invention;

Figure 9 is a perspective view of a second apparatus in accordance with the present invention;

Figure 10 is an exploded perspective view of the apparatus of Figure 9;

Figure 11 is a plan view of the apparatus of Figure 9;

Figure 12 is a front view of the apparatus of Figure 9;

Figure 13 is a rear view the apparatus of Figure 9; and,

Figure 14 is a side view the apparatus of Figure 9.

An apparatus 100 according to the present invention is shown installed on the housing 12 of a consumer unit 10 in Figures 1 and 2.

The apparatus 100 comprises a body 102 and an intumescent material portion 104 (shown in Figures 4 and 7).

The body 102 comprises a mounting portion 108 and a conduit 109. The body 102 is constructed from a sheet metal material, which in this embodiment is stainless steel (but may be other types of metal such as coated mild steel or aluminium). The mounting portion 108 defines a first flange portion 110 and a second flange portion 112. The first flange portion 110 and second flange portion 112 are both rectangular and join along their long sides. The second flange portion 112 is perpendicular to the first, such that in profile the mounting portion defines an inverted L shape (Figure 4). A rectangular opening 114 is defined in the first flange portion 110 adjacent the second flange portion 112.

The first flange portion 110 defines a plurality of fastener openings therethrough for the insertion of male fasteners such as screws 116.

The conduit 109 of the body 102 projects from the first flange portion 110 in a direction opposite to the second flange portion 112. The conduit 109 is tubular in form defining a first opening 118, a second opening 120 and a cavity 122 therebetween.

The conduit 109 is quadrilateral in horizontal cross section, defining a first wall 124, second wall 126 opposite the first and two opposing sidewalls 128, 130. The first and second walls 124, 126 are quadrilateral in shape, and in this embodiment are trapezoidal such that the conduit 109 tapers outwardly from the first opening 118 to the second opening 120. The sidewalls 128, 130 are of constant width such that the walls 128, 130 are spaced apart by a fixed offset.

A pair of attachment flanges 132, 134 extend inwardly from the sidewalls 128, 130. Each flange 132, 134 carries three threaded attachment bosses 136. The first wall 124 is attachable to, and removable from, the rest ofthe body 102 by use of threaded mechanical fasteners 138 (Figure 1) which fasten the first wall 124 to the attachment flanges 132,134. Figures 3 and 4 show the body 102 with the first wall 124 removed.

The intumescent material portion 104 is shown in Figure 7 (in plan) and comprises a flat, rectangular layer of intumescent material. The material is, for example, Firetherm Intustrap (TM) manufactured by Firetherm (TM) in the UK. The portion 104 defines a slit 140 through its thickness. The intumescent portion 104 is adhered to the underside of the first flange portion 110 such that the slit 140 is coincident with the rectangular opening 114 (shown in hidden line in Figure 7).

In use, an opening is formed in the upper surface of the consumer unit housing 12. The opening may be formed by removal of existing knock-outs, or alternatively the present invention allows the user to shape a larger / more convenient opening which should be no larger than the opening 114 in the mounting portion 108.

The apparatus 100 is then attached to the consumer unit housing 12 such that the intumescent material portion 104 is sandwiched between the mounting portion 108 and the housing 12. As such, the intumescent material portion acts as a gasket between the apparatus 100 and the consumer unit housing 12. Because intumescent materials are generally flexible and compressible, they make good seals or gaskets. Mechanical fasteners 116 penetrate the mounting portion 108, intumescent material portion 104 and grip the housing 12 (these are preferably self-tapping screws).

Referring to Figure 7, cables 14 are passed from the first opening 118, through the conduit 109 to the second opening 120 where they are fed through the slit 140 in the intumescent material portion 104 into the consumer unit 10 where they can be connected to the MCBs or RCDs. After the cables have been fed, the front wall 124 is assembled as shown in Figures 1 and 2.

In the event of a fire in the consumer unit 10, the increased heat causes the intumescent material portion 104 to expand and further seal the apparatus 100 against ingress of air (and as such oxygen). This helps to supress the fire.

It will be noted that in addition to the intumescent material portion 104 there may be provided a further intumescent material portion 106 to act as a secondary / fallback barrier. The further intumescent material portion 106 is shown in Figure 8, in planar contact with, and attached to, the first wall 124. The further intumescent material portion 106 is homothetic with the first wall 124 and as such in this embodiment is trapezoidal. As such, the further intumescent material portion 106 covers one internal side of the conduit 106.

A second apparatus 200 according to the present invention is shown in Figures 9 to 14.

The apparatus 200 comprises a body 202 and a non-intumescent fire resistant foam portion 204 (shown in Figure 11).

The body 202 comprises a mounting portion 208, an external conduit portion 209a and an internal conduit portion 209b. The body 202 is constructed from a sheet metal material, which in this embodiment is stainless steel (but may be other types of metal such as coated mild steel or aluminium). The mounting portion 208 defines a first flange portion 210 and a second flange portion 212. The first flange portion 210 and second flange portion 212 are both rectangular and join along their long sides. The second flange portion 212 is perpendicular to the first, such that in profile the mounting portion defines an inverted L shape (Figure 14). A rectangular opening 214 is defined in the first flange portion 210 adjacent the second flange portion 212.

The first flange portion 210 defines a plurality of fastener openings therethrough for the insertion of male fasteners such as screws (not shown).

The external conduit portion 209a of the body 202 projects from the first flange portion 210 in a direction opposite to the second flange portion 212 and the internal conduit portion 209b. The external conduit portion 209a is tubular in form defining a first opening 218, a second opening 220 and a cavity 222 therebetween.

The external conduit portion 209a is quadrilateral in horizontal cross section, defining a first wall 224, second wall 226 opposite the first and two opposing sidewalls 228, 230. The first and second walls 224, 226 are quadrilateral in shape, and in this embodiment are trapezoidal such that the external conduit portion 209a tapers outwardly from the first opening 218 to the second opening 220. The sidewalls 228, 230 are of constant width such that the walls 228, 230 are spaced apart by a fixed offset.

A pair of attachment flanges 232, 234 extend inwardly from the sidewalls 228, 230. Each flange 232, 234 carries three threaded attachment bosses (not shown). The first wall 224 is attachable to, and removable from, the rest of the body 202 by use of threaded mechanical fasteners (not shown) which fasten the first wall 224 to the attachment flanges 232, 234. Figure 10 shows the body 202 with the first wall 224 removed.

The second conduit portion 209b of the body 202 projects from the first flange portion 210 in a direction opposite to the external conduit portion 2091. The internal conduit portion 209b is tubular in form defining a first opening 242, a second opening 244 and a cavity therebetween. The openings 242, 244 and cavity therebetween are elongate and rectangular in shape having a width W of 15mm (Fig. 14). The length / width ratio of the second conduit portion 209b, and more particularly the cavity is at least 10:1. As can be seen in Figure 14, the width Wb of the second conduit portion 209b is less than the width Wa first conduit portion 209a.

The non-intumescent material portion 204 is shown in Figure 11 (in plan) surrounds a plurality of wires 14. The material is, for example, a foam material which can be introduced into the body 202 after the wires 14 have been installed to surround the wires and form a seal.

In use, an opening is formed in the upper surface of the consumer unit housing (similar to the housing 12). The opening may be formed by removal of existing knock-outs, or alternatively the present invention allows the user to shape a larger / more convenient opening which should be no larger than the opening 214 in the mounting portion 208.

The apparatus 200 is then attached to the consumer unit housing. Mechanical fasteners penetrate the mounting portion 208 and grip the housing 12 (these are preferably self-tapping screws).

Referring to Figure 11, cables 14 are passed from the first opening 218, through the conduit 209 to the second opening 220 into the consumer unit 10 where they can be connected to the MCBs or RCDs. After the cables have been fed, the front wall 224 is assembled as shown in Figures 9 and 10.

In the event of a fire in the consumer unit 10, the material portion 204 seals the apparatus 200 against ingress of air (and as such oxygen). This helps to supress the fire.

Variations fall within the scope of the present invention.

The housings 102 and 202 are interchangeable (i.e. housing 102 could be used with non-intumescent material and housing 202 could be used with intumescent material).

A section of cable trunking or conduit may be attached to the first opening 118, 218 to carry the cables away from the apparatus.

Only one of the first and second intumescent material portions may be provided and the invention will be effective.

It is not essential that the body 102, 202 be trapezoidal in shape. It may be rectangular or any other shape.

The front wall may be attachable by other means which facilitate easy removal and attachment, such as snap fit, or quarter turn fasteners.

The slit 140 may be an open orifice such as a slot or larger rectangular opening.

Claims

1. A consumer unit fire protection apparatus comprising:

a body defining a cable passage, the cable passage having:

at least one cable passing through the cable passage;

2. A consumer unit fire protection apparatus according to claim 1, in which the body comprises an external portion defining a first part of the cable passage, and an internal portion defining a second part of the cable passage, in which the internal portion extends into a consumer unit in use, in which the non-intumescent fire resistant material portion is positioned at least partially in the internal portion.

3. A consumer unit fire protection apparatus according to claim 2, comprising an attachment portion between the internal and external portions.

4. A consumer unit fire protection apparatus according to claim 3, in which the attachment portion is a flange extending substantially perpendicularly to the passage.

5. A consumer unit fire protection apparatus according to claim 2 or 3, in which the passage is elongate, and in which the aspect ratio passage in the internal portion is at least 10:1.

6. A consumer unit fire protection apparatus comprising:

a body defining a cable passage, the cable passage having:

7. A consumer unit fire protection apparatus according to claim 6, in which the intumescent material portion covers at least part of the second cable opening.

8. A consumer unit fire protection apparatus according to claim 7, in which the intumescent material portion defines a cable opening for passage of one or more cables.

9. A consumer unit fire protection apparatus according to claim 8, in which the cable opening is a slit.

10. A consumer unit fire protection apparatus according to any of claims 6 to 9, in which the intumescent material acts as a gasket between the apparatus and a consumer unit in use.

11. A consumer unit fire protection apparatus according to any of claims 6 to 10, comprising a further intumescent material portion disposed on an interior surface of the cable passage.

12. A consumer unit fire protection apparatus according to any preceding claim, in which the body comprises a removable portion for access to the cable passage.

13. A consumer unit fire protection apparatus according to claim 12, in which the removable portion is a wall of the body.

14. A consumer unit fire protection apparatus according to any preceding claim, in which the body comprises a conduit portion defining the cable passage and a mounting portion for engagement with a consumer unit.

15. A consumer unit fire protection apparatus according to claim 14, in which mounting portion comprises a first flange for planar engagement with a corresponding surface of a consumer unit.

16. A consumer unit fire protection apparatus according to claim 15, in which the mounting portion comprises a second flange at an angle to the first flange to engage a corner of a consumer unit.

17. A consumer unit fire protection apparatus according to claim 15 or 16, in which the mounting portion surrounds the second cable opening.

18. A consumer unit fire protection apparatus according to any preceding claim, at least partially constructed from a metal material.

19. A consumer unit fire protection apparatus according to claim 18, constructed from sheet metal.

20. A consumer unit comprising an apparatus according to any preceding claim.

Intellectual

Property

Office

Application No: GB1721123.6 Examiner: Peter Thomas-Keefe