When is supplementary bonding not required ? Tails not on rcd...

[tomodo]

Hi all, im installing a new consumer unit in a bungalow , customer wanted it moving from bathroom to hallway. The system is a tns system and the meter tails are around 7 meters long, now because of this i have installed a 80 amp switch fuse inside the meter box and the tails run from this up the cavity ( around a meter or so ) and over the top of the loft joists. Because this circuit is not on an rcd am i now required to install supplementary bonding? The cavity the tails run up is one of the bathroom walls but tails do not run over the top of bathroom. Thought about putting a 100ma time delayed rcd in aswell but dont think this would count as additional protection as its not 30ma and would struggle to fit in meter box .

Thanks

 

[Leesparkykent]

Hi all, im installing a new consumer unit in a bungalow , customer wanted it moving from bathroom to hallway. The system is a tns system and the meter tails are around 7 meters long, now because of this i have installed a 80 amp switch fuse inside the meter box and the tails run from this up the cavity ( around a meter or so ) and over the top of the loft joists. Because this circuit is not on an rcd am i now required to install supplementary bonding? The cavity the tails run up is one of the bathroom walls but tails do not run over the top of bathroom. Thought about putting a 100ma time delayed rcd in aswell but dont think this would count as additional protection as its not 30ma and would struggle to fit in meter box .

Thanks

I think you are over thinking it :santa_cheesy:

 

[tomodo]

Lol things do play on my mind alot

 

[Leesparkykent]

Lol things do play on my mind alot

The cables go up the cavity so are at a depth >50mm, are clipped to the top of the joists In the loft, don enter or pass through the bathroom so I don't see any reason for RCD protection unless the earthing arrangement is TT? Although the tails passing up the cavity isn't ideal some times you don't have much choice and have had to use the method myself in the past just advise the customer not to have the cavity filled with insulation.

 

[telectrix]

wot he just said. ^^^^^^. no need for RCD on the tails .

 

[Deleted member 26818]

Where is the meter box?

 

[7029 dave]

You are way over thinking this, why upfront 100ma rcd ?.No need what is the ZE?