Testing RCD on shower circuit

[robskiing]

test at the CU. it's easier. switch off all MCBs on the RCD you are testing. clip to earth bar, probe to L on load side of RCD. ( mft set to RCDauto ). switch on RCD, press test button on MFT. reset RCD each time it trips. read off and record trip times. enter the higher of each on schedule of test results. press test button on RCD to confirm operation. ramp test if required. done.

Yes it is a live test just follow the above instructions easier than any manual

 

[malcolmsanford]

It is a live test, you test it live with your probes, as Tel highlighted one probe croc clipped to the earth bar and with the other probe on the load side of the RCD. Is the RCD fed from a re-wirable fuse?

 

[jamminuk]

From what i can remember it looks like it was fed directly from the meter tails, 1 set goes to the main fuse board another set go into a separate RCD then onto the shower pull switch. Also whe i was taking the switch down i had a small shock off of the earth wire, is this normal? i performed an IR test between live and earth and it came back ok, not sure why there would be any current/voltage in the earth wire. I noticed something on here about earth leakage but this is a completely separate circuit for the shower, nothing to get leakage from, confused.com

Regards

Ben

 

[robskiing]

If you can get back to that job take a picture of the rcd unit showing the meter and cut out is there an earth wire from the incoming supply up to you rcd unit

 

[malcolmsanford]

If your getting a tingle of the earth, it could mean that the CPC is not connected somewhere or the neutral is loose somewhere.

Also if the RCD is fed direct of the tails then you don't seem to have any overload protection.

 

[jamminuk]

Asked the guy to take a picture and email it to me

 

[telectrix]

as you describe it, there should be a MCB alongside the RCD ( 40A? ). if not, then as malcolm says, no overload protection for the shower cable = FIRE.

 

[IQ Electrical]

as you describe it, there should be a MCB alongside the RCD ( 40A? ). if not, then as malcolm says, no overload protection for the shower cable = FIRE.

Is a shower not a fixed load?

 

[malcolmsanford]

Is a shower not a fixed load?

It is mate, but I still don't like personally going down that road of not having overload protection. I know 433.3.1 (ii) but I still like to have that safeguard, old habits I assume.

 

[IQ Electrical]

It is mate, but I still don't like personally going down that road of not having overload protection. I know 433.3.1 (ii) but I still like to have that safeguard, old habits I assume.

I agree, I'm stirring the pot

 

[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?