Testing RCD on shower circuit

[malcolmsanford]

Northern T........................ I was going to then bang on about RCD are additional protection, this that and the other lol

Plus I hate to be honest just seeing RCD protection, especially in domestic

 

[telectrix]

but 434.2 applies. the cable size is reduced from the tails size ( 16mm?) to the 6mm or 10mm of the shower circuit, so IMO that 6mm ( or 10mm ) should be protected with a suitable overload device. also, if the tails are henley blocked before the main CU, then any fault current is on the DNO fuse.

 

[malcolmsanford]

but 434.2 applies. the cable size is reduced from the tails size ( 16mm?) to the 6mm or 10mm of the shower circuit, so IMO that 6mm ( or 10mm ) should be protected with a suitable overload device. also, if the tails are henley blocked before the main CU, then any fault current is on the DNO fuse.

It's that IQ mate .....................always stirring things like you can't export a PME earth:devilish:

 

[IQ Electrical]

Meeeeeeee?

 

[jamminuk]

export pme earth? also what about the shock from the earth i got?

 

[telectrix]

cpc not earthed. broken connection somewhere. do a R1+R2.

 

[IQ Electrical]

export pme earth? also what about the shock from the earth i got?

Malcolm meant things like 'you CAN export a PME earth' many believe you can't, without actually understanding the requirements.

 

[jamminuk]

what is meant by exporting PME earth though?

 

[telectrix]

IMO "export " is a bad term. to export something means moving it from 1 place to another, when you are not doing that, you are extending it.

 

[jamminuk]

if you do a like for like swap are you obliged to perform tests? obviously for your own piece of mind

 

[telectrix]

2 questions there mate.

1. exporting earth is where you have an installation ( typically a house ) with a TN earthing system.then you want to put power in a garage, shed whatever. the remote building can either have a TT system, independent of the house, or you can " export " the house earthing to the remote building.

2. on a like for like replacement of an accessory, you don't need to do any certification, but it would do no harem to complete a MEWIC.

 

[jamminuk]

Thanks that's good to know, but now you've got me MEWIC? haha

 

[telectrix]

minor electrical works installation certificate or MWC when not in c&g la,la land.

 

[sparkyeis]

Test between live neutral and earth on the terminals at the shower 1/2 rated, x1 full cycle and x5 full cycle record highest values from x1 and x5.

 

[Des 56]

Its not yet clear if it is an Rcd

 

[telectrix]

it was before the thread diverged into exporting earths.

 

[Des 56]

I just looked through the thread and other than an insulation resistance test,nothoing else
Forget the Rcd for a moment, have you done an earth loop test ?

 

[jamminuk]

No i didn't, just IR test as i thought something must have been touching, the earth was completely bare with no sheathing as it disappeared up into the ceiling. Also instead of the switch plate being earthed the 2 cpcs were joint together with a connector block which i thought was weird, so i was in the process of removing the connector block when i got a zap. I'd turned off the main switch believing i'd isolated it, didn't realise it was being fed from a separate rcd, which was still on. Anyway after i'd connected it all up and the shower was working i was pushing the unusualy long cpc back into the box when it went BANG!