a few questions

[soulman]

hi, could you guys answer me a few questions please.

firstly should main bonding always be done regardless of earthing arrangements.


secondly should supplementary bonding in a bathroom be connected together and then to an earth terminal

thirdly a property with tt system no rcd protection old 3036 board, requires a shower does not want to upgrade board :

1.can you come out of the top of 32 amp fuse to a shower unit encloser with rcd, would this require a mcb or just the rcd as you have overcurrent protection from the fuseway.
2. could the meter tails be split via a henleys block then fed to a shower unit. and i presume this would have to incorporate a mcb as well as rcd protection.
3. would you use 63a 30ma rcd or could a 40a 30ma rcd b used in both cases

thanks for any replies. please note this is for homework only i do not intend to do any job. second yr 2330 just trying to get my head around a few things cheers

 

[pevvers]

firstly should main bonding always be done regardless of earthing arrangements.

Yes! Apart from IT installations, but that's a whole other kettle of fish...

secondly should supplementary bonding in a bathroom be connected together and then to an earth terminal

No need for supp bonding in a bathroom if all circuits are protected by RCD, and main bonding in place on incoming services to building. If not, the supp bond all metalwork together, but not back to main earth terminal.

thirdly a property with tt system no rcd protection old 3036 board, requires a shower does not want to upgrade board :

1.can you come out of the top of 32 amp fuse to a shower unit encloser with rcd, would this require a mcb or just the rcd as you have overcurrent protection from the fuseway.
2. could the meter tails be split via a henleys block then fed to a shower unit. and i presume this would have to incorporate a mcb as well as rcd protection.
3. would you use 63a 30ma rcd or could a 40a 30ma rcd b used in both cases

All are dependant on whether the system has adequate bonding and can handle the extra load, see 131.8. Size of RCD depends on power of shower, as does whether it'll be cable to run off a 30A BS3036, or whether you'll have to split the tails.

Personally, I wouldn't do any work on a TT system that didn't have a front end RCD. I would actually issue an electrical danger notification, as this is an accident waiting to happen as those fuses aren't ever gonna blow in the event of an earth fault.... Very dangerous.

 

[Guest123]

I'm totally with pevvers on the no RCD on a TT issue.

You need to stongly advise them to upgrade the CU and explain to them very apparent danger that exists.

I too would not do any work on this property unless they went ahead with the upgrade.