Shower job

[88daveb]

Im recently out my time and I've got a job to change a fuse board to a consumer unit, everything seems ok, but im skeptical about the shower, its got its own feed from the fuseboard at 30A.

I was told by the owner that he has rigged some sockets off the shower feed via a junction box.

How do i go about testing the shower feed, IR and earth loop for the shower feed.

im i safe to just apply the IR test at the consumer unit and not damage the shower, or do i need to disconnect the shower from the cc, which could prove to be knocking through a wall to get to the junction box.

its a 10kW shower if thats any help

 

[Lurch]

Well the shower feed should be feeding the shower and nothing else so I wouldn't worry too much as it's failed anyway. Test what you can and note down the faults. Test it as radial circuit as normal, forget for a moment the fact that there is a shower and also some sockets on it.

You are not expected to get to every junction box and inspect every accessory.

10kW sounds a bit high for a 30A MCB. What size is the cable and how far is the run?

 

[jimleen]

10kW sounds a bit high for a 30A MCB. What size is the cable and how far is the run?

Definitely. Chance's are it's a new or newish shower. And equally likely, even though the fuse is stated at 30A, somebody's probably bumped up the fusewire! So 6mm cable as well.

Regards

 

[88daveb]

the cable is 6mm and you can tell it was install newish compared to the other cct's. From tracing the cct it seems about 25 - 30M in cable. All the cct's in the house are radial's anyway, to be honest, the house could do with a complete re-wire but the owner doesn't have the funds.

One more question, As the lighting cct is a nightmare: For testing lighting cct's, can i just short out the dimmer switches, apparently they get damaged on an IR test?

 

[Lurch]

the cable is 6mm and you can tell it was install newish compared to the other cct's. From tracing the cct it seems about 25 - 30M in cable. All the cct's in the house are radial's anyway, to be honest, the house could do with a complete re-wire but the owner doesn't have the funds.

I would say the best course of action to remedy that would be to use the 6mm to feed the sockets and run a new 10mm in for the shower as it is undersized.

One more question, As the lighting cct is a nightmare: For testing lighting cct's, can i just short out the dimmer switches, apparently they get damaged on an IR test?

Remove from the circuit under test is the usual best option, shorting them out may or may not suffice.

 

[choccy]

a bit concerned reading all these questions deing asked from electrician doing this work. lurch is correct with the shower circuit and also testing is an art in its self and by the sounds of it you could get in trouble. i would recomend a proper rewire with ring mains and also dedicated circuits excetra.

the job sound a bish bash bosh, good luckWet Fishbad day explode

 

[ianmacd]

i would recomend a proper rewire with ring mains

Right let's have another ring/radial debate. Joke.

As for dimmers, they *should* be replaced by switches for the testing. A not so thorough way is to test at 250v across L&N and state it as a limitation of testing.

 

[Lurch]

Right let's have another ring/radial debate.

Yeah, my first thoughts as well! Don;t mention it again, think it might go unnoticed.

 

[ianmacd]

test at 250v across L&N

That could have been better worded as I meant bridging L&N and measture between them and CPC.

 

[88daveb]

Im a bit inexperienced, only out my time by months now. I havent touched many domestic electrical installations. I've only worked with industrial electrics and i just wanted to clear some issues up.

Cheers lads.