Ok just installed one of these new contactum consumers metal type ok must admit decent board question it has knock out at top and bottom for stuffing glands etc and also rear knock outs now the old board was a rewirable Wylex type so cables had to come into new consumer from rear knock out question do you have to seal around the cables as the consumer is mounted on timber
 
The minimum required is the ip2x and ip4x holes, however i would use fire-rated sealant as you must 'reasonably seal' to prevent fire from escaping.

I would just for good practice especially as its on the wooden board.
 
Intumiscent sealant - the 4 hour stuff. Thats plenty of time. Evostick, siroflex do a tube too.. Even wickes!
 
There is no specific reg for sealing the entry's but was reading IET wiring matters on amendment 3 and it says it is important for the installer to seal all openings into the enclosure or cabinet for cables, conduits, trunking or ducting that remain after the installation of cables. The intent of the sealing is to ensure that, as far as is reasonably practicable, any fire is contained within the enclosure or cabinet and the escape of flames to the surroundings of the cabinet or enclosure or into conduits trunking or ducting is minimised, as intended by Regulation 421.1.201. Good workmanship and proper materials must be used, and account must be taken of the manufacturer’s relevant instructions, if any.

Consumer units - IET Electrical

If I did choose to seal the holes I would probably use pyro mate.

Pyro Mate Silicone
 
Last edited by a moderator:
I've seen that document before on similar threads. It uses terms, like good workmanship and 'contain.....escape of flames.......as intended by regulation 421.1.201', which actually makes no mention of sealing cable entries. I'm no expert on what product is suitable to do such a job (intumescent), its compatibility with pvc cables. I've only installed Wylex 3rd A, and they have no recommendations on the subject. Are we in danger of taking this thing too far? How would we then, in the case of the mcb's, rcd's etc (which are still made of plastic), use 'good workmanship' to seal these gaps, when a fire takes hold in a 3rd amendment CU? If the lid of a 3rd amendment CU is not air tight, why should 'we', be responsible for sealing cable entries. Surely, this is the manufactures responsibility, in their design not ours?
 
Sealing the holes when the cu is mounted on wood won't help much. Fire will pass through the thin sheet steel as if it wasn't there. Being non combustible is not the same thing as being fire proof.
 
I've seen that document before on similar threads. It uses terms, like good workmanship and 'contain.....escape of flames.......as intended by regulation 421.1.201', which actually makes no mention of sealing cable entries. I'm no expert on what product is suitable to do such a job (intumescent), its compatibility with pvc cables. I've only installed Wylex 3rd A, and they have no recommendations on the subject. Are we in danger of taking this thing too far? How would we then, in the case of the mcb's, rcd's etc (which are still made of plastic), use 'good workmanship' to seal these gaps, when a fire takes hold in a 3rd amendment CU? If the lid of a 3rd amendment CU is not air tight, why should 'we', be responsible for sealing cable entries. Surely, this is the manufactures responsibility, in their design not ours?

Agreed, we probably won't find out until people start having their scam assessments after jan 2016. If people start getting tugged for not sealing......
 
...Better get some tick-sheets printed,for different cable types entering DB,and their compatibility with differing intumescent sealants...

...I'm guessing,that will prove as useful,as this forums "spell-check",on the word "intumescent"...Oxford 1 - Yankees 0 :49:
 
Ok just installed one of these new contactum consumers metal type ok must admit decent board question it has knock out at top and bottom for stuffing glands etc and also rear knock outs now the old board was a rewirable Wylex type so cables had to come into new consumer from rear knock out question do you have to seal around the cables as the consumer is mounted on timber

This doesn't become dangerous until January 1st 2016, so still safe to fit as normal for the present. :D
 
Just got the latest Guidance note 1, Selection & Erection. Looked up 421.1.201 in the hope it might provide some practicable advise on the subject. Just repeats pretty much is what said in BS7671. Does say however, Guidance note 4 gives further information about the requirements. Me smells a rat Fawlty, they want me to buy another book! Anyone got the latest GN 4?
 
Just got the latest Guidance note 1, Selection & Erection. Looked up 421.1.201 in the hope it might provide some practicable advise on the subject. Just repeats pretty much is what said in BS7671. Does say however, Guidance note 4 gives further information about the requirements. Me smells a rat Fawlty, they want me to buy another book! Anyone got the latest GN 4?
I have all of the Guidance Notes.

However I don't have them on me at present, so you might have to wait a couple of days unless someone else has it handy!
 
GN4 on Consumer units.

3.8 Enclosures
Where enclosures are constructed on site, reference must be made to the appropriate product standard for the necessary resistance to heat and fire. In the absence of such a standard, maximum likely temperatures of the enclosure must be determined and enclosures selected that are well able to withstand these temperatures.

BS 476 Fire tests on building materials and structures (Part 4 – Non-combustibility test for materials, Part 12 – Method of test for ignitability of products by direct flame impingement) provides type tests for materials.

Where equipment is installed in an enclosure or enclosed space, e.g. ballasts or other controlgear within a ceiling, adequate arrangements must exist for safely dissipating heat generated.

3.8.1 Consumer units and similar assemblies in domestic premises
Regulation 421.1.201, which was added to BS 7671:2008 by Amendment No. 3 (2015), requires consumer units and similar switchgear assemblies installed in domestic (household) premises to comply with BS EN 61439-3 and to either:

(a) have their enclosure manufactured from non-combustible material or
(b) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.

An example of a non-combustible material, according to Note 1 to Regulation 421.1.201, is ferrous metal, such as steel.

The implementation date for Regulation 421.1.201 is 1 January 2016 (six months after Amendment No. 3 comes into effect); see Note 2 to the regulation. However, this does not preclude compliance with the regulation prior to that date.

Where option (b) above is used, it is important that the cabinet or enclosure is suitably selected and erected to meet the requirements of Regulation 132.12. These relate to adequacy of space for initial installation and later replacement individual items equipment, and accessibility of the equipment for operation, inspection, testing, fault detection, maintenance and repair.

The intent of Regulation 421.1.201 is, as far as is reasonably practicable, to contain any fire within the non-combustible enclosure or cabinet and to minimise the emission of flames to the surroundings or into conduits trunking or ducting. Consequently. both of the following are necessary, irrespective of which of options (a) or (b) is adopted.
The non-combustible enclosure or cabinet must provide a complete envelope (e.g. base, cover, door and any components such as hinges, screws and catches) as necessary to maintain fire containment. All blanks, circuit-breakers and other devices must be contained within the non-combustible enclosure or cabinet. The installer must seal all openings into the non-combustible enclosure or cabinet for cables, conduits, trunking or ducting that remain after the installation of cables. Good workmanship and proper materials must be used and account must be taken of the manufacturer's relevant instructions, if any.

The phase 'similar switchgear assemblies' in Regulation 421.1.201 means assemblies used for the same fundamental application as a consumer unit. An example could be a three-phase distribution board intended to be operated by ordinary persons.

Regulation 421.1.201 is intended to apply consumer units and similar switchgear assemblies to BS EN 61439-3 inside all domestic (household) premises, including their integral / attached garages and outbuildings and those in close proximity.

3.9 Terminations
Regulation 526.5 is the general requirement for the enclosure of terminations and joints of live conductors and PEN (combined protective and neutral) conductors. A further important requirement is to provide an enclosure which will protect the joint or connection against the environment.

Poor terminations and connections are cited as a frequent cause of fire, and close attention is required by the designer, the installer and the person responsible for the inspection and testing to all aspects of the subject.

For this reason, Regulation 526.5 requires that all terminations and joints at whatever voltage, including ELV, shall be made within a suitable enclosure. Because there is always a risk of overheating and consequent fire at a joint or termination, these must be enclosed and the enclosure where not incorporated in suitable equipment or accessory must meet the specified fire resistance requirements. This applies equally to LV and ELV connections, to luminaires and to similar equipment. The relatively high currents of ELV equipment mean particular care has to be taken with joints and terminations. When compression joints are used, crimping tool, lug and cable must be compatible.

Other matters which should be considered under this heading are:
(a) dirty or misaligned equipment contacts which may give rise to local heating, and
(b) loose or inadequate cable supports which may place mechanical stresses on connections, causing overheating.

One method, which could be considered when inspecting electrical installations for signs of overheating, is the use of thermal imaging. This is not required by BS 7671 and would therefore be in addition to the inspections and tests stated in Part 6 of BS 7671.

The use of thermographic surveying is discussed in Guidance Note 3: Inspection & Testing.
 

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Green 2 Go Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses Heating 2 Go Electrician Workwear Supplier
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Advert

YOUR Unread Posts

Daily, weekly or monthly email

Thread starter

Joined
Location
Wirral
Business Name
Farm electrics

Thread Information

Title
Metal consumer
Prefix
N/A
Forum
Periodic Inspection Reporting & Certification
Start date
Last reply date
Replies
16

Advert

Thread statistics

Created
Farmelectrics,
Last reply from
Midwest,
Replies
16
Views
2,800

Advert

Back
Top