UK Metal clad cable entry

[Craighrvy]

Hi all, level 3 qualified sparky here, just getting back into it after some time out.
So, what is considered best practice these days when installing a metal clad consumer unit.
Are all these Fancy Dan cable glands actually required or are they just another money spinner.
I've found if you have a lot of cable going in the top, using multiple 20mm knock outs looks crap.
Older style cu I used to just run some trunking across the top which looked good, then use grommets or bushes to go through.
Also the new fire rated meter tails glands are an absolute nightmare to prep, same as the twin and earth shaped ones as they are barely big enough to get the cable through even without the gland tightened up. Any trick to these or are standard glands considered acceptable alternatives.

Last question, I'm installing a consumer unit where meter tails are going up inside a cavity from the meter box - joy.
Replacing with 25mm, but do I need to have a gland going in the rear of the box, or is grommet strip deemed acceptable with some fire sealant or foam applied in the remaining gap. Any tips on good stuff to use

Cheers

 

[ChrisElectrical88]

Think with cables going in the top, it varies from job to job. Sometime trunking, sometime stuffing glands. Tails can come through the rear knockouts no problems, use grommet strip or some boards have plastic things pre fabricated to fit those holes.
Remeber changing a domestic mains board must be notified.

 

[Dustydazzler]

These jobbies are the nuts...

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QUIXX® membrane cable entries flame-retardant, EMT-F - Cable entries - WISKA - make power smile

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[westward10]

Cable entries do not need to be fire rated, the consumer unit isn't they just need to maintain the IP of the enclosure.

 

[Dustydazzler]

As above you just need to maintain the integrity of the consumer unit.
so if you make a hole in it then use the appropriate sized glad or grommet.
all these folk who gun expanding foam around the inside of the board are just making it a nightmare for the next bloke who has to work on it...

 

[MJPD29]

Hi all, level 3 qualified sparky here, just getting back into it after some time out.
So, what is considered best practice these days when installing a metal clad consumer unit.
Are all these Fancy Dan cable glands actually required or are they just another money spinner.
I've found if you have a lot of cable going in the top, using multiple 20mm knock outs looks crap.
Older style cu I used to just run some trunking across the top which looked good, then use grommets or bushes to go through.
Also the new fire rated meter tails glands are an absolute nightmare to prep, same as the twin and earth shaped ones as they are barely big enough to get the cable through even without the gland tightened up. Any trick to these or are standard glands considered acceptable alternatives.

Last question, I'm installing a consumer unit where meter tails are going up inside a cavity from the meter box - joy.
Replacing with 25mm, but do I need to have a gland going in the rear of the box, or is grommet strip deemed acceptable with some fire sealant or foam applied in the remaining gap. Any tips on good stuff to use

Cheers

Grommet strip is definitely acceptable in the rear of the consumer unit. No need to gland tails rear entry. Bit if intumescent silicone afterwards and jobs a goodun.

 

[davesparks]

Intumescent sealant is unnecessary and unhelpful to the next person trying to get a a cable in to the CU to use those spare ways you have left for them.

 

[MJPD29]

Intumescent sealant is unnecessary and unhelpful to the next person trying to get a a cable in to the CU to use those spare ways you have left for them.

Ok. Everyone's entitled to their opinion.

 

[davesparks]

Ok. Everyone's entitled to their opinion.

Yes they are, but when their opinion has no basis in the regulations what is its relevance?

 

[Dustydazzler]

It is pprobably wise to put some
poly filler around the hole in the wall that thr cables poke through, but not gunning mastic or expanding foam once the board is fitted isn’t necessary at all imo...

 

[Ian1981]

If the CU was fire rated then you would have to seal it, but it’s not , so there’s no need to use fire foam or sealant.
Contrary to belief, good practice doing it, is not good practice at all.

 

[Dustydazzler]

Fire rated is incorrect terminology

non combustible construction is the proper term

 

[Ian1981]

Fire rated is incorrect terminology

non combustible construction is the proper term

And that’s my point.
Its not fire rated hence it doesn’t have to be sealed, it is however to be made of a non combustible material or can be made of a combustible material, housed in a non combustible cabinet.