Wiring an 11.2kW Electric Shower

[Miguel Sasso]

Hi everyone

Was hoping somebody could tell me whether the way in which I have wired my 11.2kW electric shower is appropriate or not. I did the wiring myself about 3 years ago - Would probably get a professional in these days, but was a skint student at the time!

I had an electrician in yesterday and he commented that it was not suitable because of the type of RCCD used. He then went on to tell me that I would be as well getting a new consumer unit, fitted with RCBO's (my current consumer unit uses MCB's which are of a different type to the ones commonly sold these days). Between parts (=A390) and labour (=A3150) i would rather not do this...

The wiring goes like this:

- Consumer Unit (100A) fitted with 45A MCB - Tails - 63A, 30mA RCCB - 16mm2 T&E - 50A Pull Switch - 16mm2 T&E to shower

He told me that I should not be using a 63A RCCB for the shower (too high). My thinking when I installed the shower was that this would be ok as I have the 45A MCB for overcurrent/short-circuit protection and the 30mA RCCB for current leakage. I thought that the 63A rating purely relates to the maximum allowable current which can be passed through the RCCB.

Can anybody confirm whether this is ok from the point of view of:

1 - Safety 2 - Wiring regs (forgetting the fact i shouldn't be doing the wiring in the first place)

Many thanks, Miguel

[dom]

That's certainly my understanding!

Screwfix in fact advertise a 63A rcd for exactly that purpose:

screwfix would probably tell you nails make good fuses)

[cynic]

You seem to have had the misfortune to have commissioned a wanker to look at your installation. If he is trying it on like this he will rip you off elsewhere during the job.

[Andrew Gabriel]

Yes. Get rid of the electrician. He's either clueless or dishonest.

45A MCB is a bit on the low side, but if it's worked to date, and doesn't get too hot with a long shower, then you've got away with it.

Inspect all the connections to check for any signs of heating. Could also retighten terminal screws (with power off, needless to say).

[Lurch]

Also worth checking everything after some complete retard has been poking around in it anyway. Nothing wrong with MCB's and you don;t

*need* RCBO's to have a compliant installation.

[ARWadsworth]

Was hoping somebody could tell me whether the way in which I have wired my 11.2kW electric shower is appropriate or not. I did the wiring myself about 3 years ago - Would probably get a professional in these days, but was a skint student at the time!

I had an electrician in yesterday and he commented that it was not suitable because of the type of RCCD used. He then went on to tell me that I would be as well getting a new consumer unit, fitted with RCBO's (my current consumer unit uses MCB's which are of a different type to the ones commonly sold these days). Between parts (£90) and labour (£150) i would rather not do this...

The wiring goes like this:

- Consumer Unit (100A) fitted with 45A MCB - Tails - 63A, 30mA RCCB - 16mm2 T&E - 50A Pull Switch - 16mm2 T&E to shower

He told me that I should not be using a 63A RCCB for the shower (too high). My thinking when I installed the shower was that this would be ok as I have the 45A MCB for overcurrent/short-circuit protection and the 30mA RCCB for current leakage. I thought that the 63A rating purely relates to the maximum allowable current which can be passed through the RCCB.

Can anybody confirm whether this is ok from the point of view of:

1 - Safety 2 - Wiring regs (forgetting the fact i shouldn't be doing the wiring in the first place)

Many thanks, Miguel

Did you not intend to say "I wired the shower up just before Part P came into force"?

Your electrician sounds dodgy your wiring sounds fine.

If the other electrics in the bathroom are not RCD protected then they and the shower should be supplementary bonded.

Cheers

Adam

[Miguel Sasso]

He was quite convincing and I was beginning to doubt myself for a while. Yes, you are right, I did the wiring just before part P came into effect :)

I will take the advice above onboard and recheck all the terminals.

Funny, I could only source a 40A on a particular website and he said that would be fine!

Many thanks to everyone that replied. I have found this newsgroup to be invaluable in the past and it has proved itself again.

Miguel