Shower not on RCD

[wiggles]

Thank you guys

You have all gone to a lot of trouble to help me understand the reasons why an RCD is desirable in this situation and I really appreciate it – that’s what I wanted, a better understanding.

Fitting another enclosure would be tricky due to space constraints where the CU is located. It’s alongside a combi boiler so there is no space to the left. The right hand side is very close to the wall and the top is close to the ceiling. There is plenty of space underneath but cable lengths may come into play. Reorganisation within the CU is probably the only realistic option. I will take some further photos this afternoon and see whay you guys think.

I'm disappointed that the electrician did not come up with a better solution when they had the extension built. Although the CU was not moved, the cutout was so it would have been a simple matter for him to install another smaller CU at the time with plenty of room for expansion or even replace the existing one.

 

[Paul Barker]

Probably the case that the builder did not listen to the electrician.

 

[wiggles]

Hi,

Here is a new picture I took this afternoon:

The shower circuit is the leftmost, next to the main isolator. Is this 6mm2 cable?

I note that for the two circuits that the spark installed, he has not even gone to the trouble of shrouding the CPC. I guess he also replaced the cooker cable as it shares the same CPC terminal as the shower (the kitchen was replaced at the same time) - it looks like the old cable was just cut short and left. I know this should be tied to the earth terminal but it looks like it's too short to be connected now.

It looks like the best course of action would be to swap the upstairs sockets MCB with the shower MCB (and move the matching neutrals). It looks straightforward so I’m tempted to do it myself - would this be modifiable or is it just updating existing circuits?

Thanks again for your help.[/img]

 

[Adam_151]

The problem is that a lot of people (myself included) would argue that its desireable to have upstairs sockets on RCD as well, and besides this time next year the 17th edition will have come in and all signs point to it requireing all general purpose sockets to be on RCD.

I personally would probably replace the CU in your situation, but thats not really recommended for a DIYer unless they happen to have the correct kit to test the installation

 

[Taylortwocities]

The next edition may (or may not) require all sockets to have an RCD
The next edition may (or may not) require all lights in bathrooms to have an RCD.
But regulations are not retrospective so you will not be obliged to do this as soon as a new regs book comes out.

Your concern is no RCD on a shower and I would say that is something you should do.

You are correct in your description.

Switch off main switch
Remove 6mm live cable from shower MCB. Remove its neutral from the neutral busbar (on the left).
Remove live cables from upstairs ring mcb (32A) and their associated neutrals (they will go to the neutral terminals under the RCD)
Swop over the two contact breakers so the 32A is at the left hand side next to the main switch. the shower one will be to the RHS of the RCD.
Put the shower live cble into the 40A MCB and its neutral in tthe neutral block under the RCD
Put the two live cabkles from the ring into the 32A mcb and the two neutrals into the neutral busbar next to the main switch.

You should swop over the earth cables of the two circuits so they correspond with their new MCB positions.

That should be it.

My one concern is that the RCD is rated at 60A. So you will have the downstairs ring (kitchen appliances) and the shower running through that. I dont remember if u posted what teh rating of the shower is?

 

[bernardgreen]

If you do work on the CU beware that there is a live terminal above the main swith that will still be LIVE when the main switch is OFF and is next to the terminal on the MCB that you will be working on if you move the shower cable.

 

[Taylortwocities]

Well spotted Bernard - cripes, no shrouds on the tails! The new crabtrees are so much better no live busbars anywhere.
Be very careful if/when you do the change over.
Is there an isolation switch between the meter and the consumer unit??
You'll have to remove the live busbar at the bottom of the MCBs to do it. Make sure its all done up again nice and tight.

 

[ColJack]

i count 6 circuits but only 5 neutrals terminals used.. please seperate out the neutrals..

I also see 2 earths from the 6mm²'s not sleeved..

can you get a photo of just the RCD and the 2 breakers off it, and a little to the right of them.. i want to see what they're mounted on.. din rail?

 

[Taylortwocities]

I think there are 6 neutrals on the non-rcd side. Two blacks are in one terminal 9probably lighting.

These old crbtree boards do have din rail but with exposed clamps for live busbar - like a lot did, at that time.

 

[ColJack]

what I'm thinking is that since the supply to the RCD is cable from the main busbar, and the busbar from the RCD is not integral to the CU ( like the square D plug in ones.. ), then it's easy enough to change the RCD and breakers for newer ones using a double wide RCD not a 4 wide as is installed..
this leaves 2 extra spaces to put new breakers in.. and allows for an uprated rcd

 

[wiggles]

Is this any clearer?

 

[wiggles]

If you do work on the CU beware that there is a live terminal above the main swith that will still be LIVE when the main switch is OFF and is next to the terminal on the MCB that you will be working on if you move the shower cable.

Good point. I won't proceed unless there is an isolator between the meter and the CU. I would be surprised if there is not one as the DNO had to move the incoming cable, cutout and meter when the extension was built.

 

[wiggles]

i count 6 circuits but only 5 neutrals terminals used.. please seperate out the neutrals..

I also see 2 earths from the 6mm²'s not sleeved..

Yes, they are the two additional circuits installed by the spark.

can you get a photo of just the RCD and the 2 breakers off it, and a little to the right of them.. i want to see what they're mounted on.. din rail?

Yes, I've added another photo.

The plot thickens...The first neuteral connection is the tail for the RCD, so there are actually only 4 terminals used for the 6 non-RCD connections.

 

[ColJack]

looked like the 3 small cables were: 1 in number 2 and 2 in number 3..
are all 3 in one terminal..?

are the breakers on a din rail?

 

[RF Lighting]

The old starbreaker CUs have a half din rail like the old hager range.

Also @ OP part of your main switch is broken off which is why the incomming shroud is missing.