Does this RCD pic look right?

Rabbitsnose · Posted: Fri Apr 20, 2007 8:54 pm Post Subject: Does this RCD pic look right?

Just moved into a new house and looking at the electrics. Not sure about this bit. There's an electric shower (not the heating type), with the cable going to this RCD :pic here: http://www3.webng.com/alanw/rcd1.jpg
The wires at the top come from the shower and the ones at the bottom go to the consumer unit, but I'm not sure about those earth wires being joined like that. Does it look right to you experts?

sparkyspike · Posted: Fri Apr 20, 2007 8:59 pm Post Subject:

It's ok for a connector like that to be used. If I were to be picky, I would say that the earth sheath should completely cover the wire, and that there shouldn't be a gap at the top of the unit where the cable goes through.

PS What caused you to go looking inside the enclosure in the first place?

Rabbitsnose · Posted: Fri Apr 20, 2007 9:13 pm Post Subject:

Thanks for that Sparky. I was just having a look out of paranoia about mixing water and electricity. we've literally just moved in and no-one's had a shower yet so i wanted to check. I suppose another way would be to get the mother-in-law to go first...

ricicle · Posted: Fri Apr 20, 2007 9:16 pm Post Subject:

That RCD is under-rated @ 25A for all the modern day showers.It also seems to look like 2.5mm² cable which only has a maximum rating of 27A which is still way under for a decent shower.Do you know what size the shower is in Kw?

EDIT:Could be 4mm² but still under for modern showers and the RCD is still a concern.

__________________
Empty barrels make the most noise.

Rabbitsnose · Posted: Fri Apr 20, 2007 9:34 pm Post Subject:

Thanks for that Ricicle. The last owner left the manual and according to that the shower takes 140 watts. Doesn't seem much to me but maybe that's because it's not a heating shower.

JohnD · Posted: Fri Apr 20, 2007 10:02 pm Post Subject:

is it a power shower with an electric pump but no electric heater?

lookinn · Posted: Fri Apr 20, 2007 10:18 pm Post Subject:

Rabbitsnose said it was only a power shower no heater. Don't try to confuse him with undersize cable issues which it is not.

Lectrician · Posted: Sat Apr 21, 2007 5:55 am Post Subject:

I would like to have seen TRS glands top and bottom of that enclosure, or atleast clips to support the cable and prevent tugging.

The OP stated in his first post it had no heater elements. The cable size is fine.

HOWEVER - there should be some fusing DOWN somewhere! I would expect to see a fused connection unit near the shower with a 3 or 5 amp fuse in. Where does the feed to the RCD come from? An MCB in the consumer unit? What rating?

Rabbitsnose · Posted: Sat Apr 21, 2007 8:49 am Post Subject:

Thanks to all for the posts. Just to be clear, it's a power shower but doesn't heat the water. Lectrician, the bottom wires go to the consumer unit and into an MCB of 16 amps. Maybe this should be smaller?

JohnD · Posted: Sat Apr 21, 2007 9:09 am Post Subject:

I agree with Lectrician.

There ought to be an isolator near the shower (but outside the bathroom unless we want to get into zones). This would typically be a DP switch or an FCU (which is a Fused Connection Unit, and yours should incorporate a switch). If it has an FCU, you can put a 3A or 5A fuse in it. This is the easiest and cheapest way to fuse it down. Changing the MCB would be more work and is changing the circuit characteristics so not strictly speaking a DIY job.

Get some cable clips to support the cable where it goes into the enclosure so that the wires cannot be tugged out of the terminals (yes, glands would be better)

As it is just a shower pump the cable size and the RCD rating are fine.

Rabbitsnose · Posted: Sat Apr 21, 2007 10:13 am Post Subject:

Many thanks for that JohnD. Very clear. In fact, now you've said that about the FCU I've traced the top wires from the picture back and they do indeed go to a fused unit with red light and a switch. The fuse in there is 3 amps. From this unit the wires go on to the shower. Unfortunately this FCU is in the bathroom. It's on the wall farthest from the shower and bath so you can't reach it while you're having a shower but still maybe this is not correct. However, I think I'm getting into a different subject now so maybe this is for another thread. Thanks for everyone's help.

ricicle · Posted: Sat Apr 21, 2007 11:35 am Post Subject:

Yeah, sorry I didn't see the "not the heating type" in the original post

__________________
Empty barrels make the most noise.

JohnD · Posted: Sat Apr 21, 2007 2:17 pm Post Subject:

A switch may be permitted in the bathroom, depends how far from the bath and shower it is. Have a look at page vii

click here

Rabbitsnose · Posted: Sun Apr 22, 2007 4:56 pm Post Subject:

Thanks for the link JohnD. Reading that it looks like I'll need to get the switch moved. Thanks again.