Consumer unit as recommended by governing body

[dlt27]

Hi all, I phoned my governing body yesteday to ask the dreaded question about TT system with metal consumer unit. His reply was that a tails gland should be used with clamp for tails in board and a 100mA rcd as main switch to protect tails feeding 30mA rcd's. He also said a fire resistant material should be used in plastic trunking above board to stop fire escaping past holes where cables enter the board and setting the trunking on fire. I said I thought as long as ip ratings for horizontal and vertical edges were met there wasn't a requirement for the board to be fire rated. His reply was that anywhere air could get in or fire could escape from should be sealed else there is no point fitting a metal board.
We both finally agreed that I could fit a 100mA rcd in plastic enlosure before board as it woudn't be classed as switch gear (wylex also recommed this practice on there youtube video even though I disagree and think it should be classed as switchgear).
I understand eveything he said, but where do you stop with extra expense for materias, labour etc
I just wondered how far the rest of you go and what practices you would recommend in this situation. Thanks in advance.

 

[Octopus]

The confusing situation continues. The Muppets at the IET and the LFB must be really happy about the stupidity of the regs they have come up with.

 

[NDG Elecs]

Out of interest which scam are you with? I thought the 'guidance' was now fairly well established myself. Though I wouldn't have said that six months ago. And I would class a separate RCD/ISO/etc as similiar switchgear myself, I can't see how it wouldn't be. Ask your tech guy at the scam to email you with what they said....it would be interesting to see if they back tracked a little.

 

[dlt27]

What estalished guidance exactly are you talking about or what do you recommend? Thanks. The organisation is NAPIT.

 

[NDG Elecs]

I'm with NAPIT too. One of their tech guys didn't instill confidence in me when I rang once! There are articles in the IET Wiring Matters, guidance from the schemes, there is also a twenty minute video on you tube which has various 'big wigs' from IET/scams/manufacturers discussing the requirements.

 

[mattg4321]

Hi all, I phoned my governing body yesteday to ask the dreaded question about TT system with metal consumer unit. His reply was that a tails gland should be used with clamp for tails in board and a 100mA rcd as main switch to protect tails feeding 30mA rcd's. He also said a fire resistant material should be used in plastic trunking above board to stop fire escaping past holes where cables enter the board and setting the trunking on fire. I said I thought as long as ip ratings for horizontal and vertical edges were met there wasn't a requirement for the board to be fire rated. His reply was that anywhere air could get in or fire could escape from should be sealed else there is no point fitting a metal board.
We both finally agreed that I could fit a 100mA rcd in plastic enlosure before board as it woudn't be classed as switch gear (wylex also recommed this practice on there youtube video even though I disagree and think it should be classed as switchgear).
I understand eveything he said, but where do you stop with extra expense for materias, labour etc
I just wondered how far the rest of you go and what practices you would recommend in this situation. Thanks in advance.

Good luck making it air tight. What an absolute load of tosh.

 

[dlt27]

Can anybody recommend exactly what they do.. Also i keep hearing about these tails glands that cost a lot of money . What is wrong with putting tails in trunking and using gromett strip in the knockout to taketails though?

 

[soulman]

I had a similar problem, as I do a lot of work on TT earthing systems. I have spoken to wylex direct about their video. They told me to ignore it as you cannot use the plastic REC2 enclosure. The video was first produced as an idea before the reg came into force apparently. I was told by Hager technical that a 100ma main switch was not necessary as the risk was low. I asked could I have that emailed to me, he said no! It is up to you to make a decision, based on risk assessment. I personally think that wylex's video was spot on.
But now on TT systems, I use a dual rcd board, replace the main switch with 100ma Stype. I install 2 battons either side of the board, screw a sheet of plasterboard to the battons. I take some of the rear knock outs off & fit the board, I cut a small section out of the rear of the plasterboard & bring the tails in. Where possible I bring the circuits through the rear as well. Once all the conductors are terminated, i fill any gaps with intumescent silicone.

Cheers

 

[TJ Anderson]

Soulman, why bother putting S Type downstream of the tails entering metal enclosure? Are you not still bringing non rcd protected tails into a metal enclosure with an EFLI too high to provide satisfactory disconnection time due to high impedance from TT earthing arrangement.

 

[HappyHippyDad]

Can anybody recommend exactly what they do.. Also i keep hearing about these tails glands that cost a lot of money . What is wrong with putting tails in trunking and using gromett strip in the knockout to taketails though?

The answer is 'no' I'm afraid dlt. I think you're asking for a generic, accepted way of meeting the demands of amd 3 with regard to a TT install. Unfortunately, everyone (schemes, IET, electricians etc) seems to have their own views although there is a 'degree' of clarity in this video from the IET at one of the elex shows https://m.youtube.com/watch?v=nJvLT7uwO58 I can't remember at what point they mention glands/grommets, but somewhere they do clearly say a normal grommet is OK for your cables unless entering from the top (or TT then use gland for tails and main earth).

I have just fitted a metal board (dual RCD) on a TT. I choose to use one of the fancy wiska glands as at £6 (from wilts), I didn't think it was 'too' expensive. I think its highly unlikely the tails are just going to decide to come out of the main switch if screwed in at the correct torque, however I do like the fact that giving them some support (i.e the gland) when they enter the board does decrease any movement inside the board if the tails are disturbed from outside. Hagar make a board with tails clips above the main switch if you wanted to be extra cautious. Personally I would be happy to use a normal 40mm stuffing gland next time for the tails and main earth to enter, unless they are entering from the top in which case I would stick with the wiska gland as I could be certain that the IP4X rating is met.

I fitted a time delayed RCD as the main switch as otherwise you are solely reliant on the 2 RCD,s for your fault protection. There isn't a regulation to do this, just seems to be good practise. Personally, I would prefer to fit the time delayed RCD in one of these REC2S | Wylex 2 Way Isolator Switch, 100A NH | Wylex but I thought my scheme would frown on this as its plastic and clearly switchgear.

Soulman, why bother putting S Type downstream of the tails entering metal enclosure? Are you not still bringing non rcd protected tails into a metal enclosure with an EFLI too high to provide satisfactory disconnection time due to high impedance from TT earthing arrangement.

You are, but I think the point is that the flexible cables from the bottom of the main switch to each RCD have some fault protection and also its offering back up fault protection should the RCD's fail. I'd still much rather put the tails in one of those REC switches though!

 

[Pete999]

Hi all, I phoned my governing body yesteday to ask the dreaded question about TT system with metal consumer unit. His reply was that a tails gland should be used with clamp for tails in board and a 100mA rcd as main switch to protect tails feeding 30mA rcd's. He also said a fire resistant material should be used in plastic trunking above board to stop fire escaping past holes where cables enter the board and setting the trunking on fire. I said I thought as long as ip ratings for horizontal and vertical edges were met there wasn't a requirement for the board to be fire rated. His reply was that anywhere air could get in or fire could escape from should be sealed else there is no point fitting a metal board.
We both finally agreed that I could fit a 100mA rcd in plastic enlosure before board as it woudn't be classed as switch gear (wylex also recommed this practice on there youtube video even though I disagree and think it should be classed as switchgear).
I understand eveything he said, but where do you stop with extra expense for materias, labour etc
I just wondered how far the rest of you go and what practices you would recommend in this situation. Thanks in advance.

Governing body, do you mean scam, sorry scheme say like NICEIC and the likes

 

[Leesparkykent]

Hi all, I phoned my governing body yesteday to ask the dreaded question about TT system with metal consumer unit. His reply was that a tails gland should be used with clamp for tails in board and a 100mA rcd as main switch to protect tails feeding 30mA rcd's. He also said a fire resistant material should be used in plastic trunking above board to stop fire escaping past holes where cables enter the board and setting the trunking on fire. I said I thought as long as ip ratings for horizontal and vertical edges were met there wasn't a requirement for the board to be fire rated. His reply was that anywhere air could get in or fire could escape from should be sealed else there is no point fitting a metal board.
We both finally agreed that I could fit a 100mA rcd in plastic enlosure before board as it woudn't be classed as switch gear (wylex also recommed this practice on there youtube video even though I disagree and think it should be classed as switchgear).
I understand eveything he said, but where do you stop with extra expense for materias, labour etc
I just wondered how far the rest of you go and what practices you would recommend in this situation. Thanks in advance.

http://www.hager.co.uk/news-exhibit...2008/latest-news/mythbreakers-story/56586.htm

 

[HappyHippyDad]

Hager - Mythbreakers story

Lee, Hagar seems to be your choice of units so I hope you don't mind me asking... I can't quite see the difference between the design 10 and 30? Is it just that the 30 comes with the accessories (grommet strip, tail clamp etc)?

Also, costwise they seem quite steep compared to wylex which is what I use at present. What sort of price are you paying for a dual RCD 10 way?

PS.. Sorry dlt for going off track on your thread.

 

[Andy78]

Lee, Hagar seems to be your choice of units so I hope you don't mind me asking... I can't quite see the difference between the design 10 and 30? Is it just that the 30 comes with the accessories (grommet strip, tail clamp etc)?

Also, costwise they seem quite steep compared to wylex which is what I use at present. What sort of price are you paying for a dual RCD 10 way?

PS.. Sorry dlt for going off track on your thread.

Comparison here
Hager - Comparison Table of the Design Range

The design 30 also has a lockable lid clasp

I'm paying just under a ton (inc VAT) for a 5+5 design 10 with breakers

 

[GEOFF S]

Hi

This may help
Hager - Mythbreakers videos

Cheers