Consumer unit help ?

[dek_d]

Hi All,

I would be grateful if someone with a little more electrics know how, would be kind enough to take 5 mins to assist me with a few questions.......
I have recently moved house and decided to add a spur socket to a room we have been decorating. In doing so I obviously went to the Cosnumer unit to see what I had in there. In looking at the unit and trying to identify the circuits, all of which were not labelled I noticed that the bus bar was not there. Each MCB is linked at the bottom or where the bus bar was on our old CU with little lengths if Red Cable from what I think was 2.5mm T&E? I'n no expert but it's the size i think it is? I don't know if it's problem, hence my asking the question and it's curiosity more than anything else....just like to have a little understanding of my CU. Why would the bus bar not be there and why are the MCB's connnected at the bottom in this manner?

Last one - When trying to locate the circuit to isolate the upstairs mains sockets, I have found that I have to isolate two MCB's? It would appear that there is a circuit for both upstairs and downstairs, but I have to switch both off in order to isolate any one of them. If I turn off what I think is downstairs, it does nothing until I isolate another and then they both go off? Please excuse my ignorance but my knowledge is a bit limited. Any ideas, would be greatly appreciated.

Thanks in advance!

 

[JohnD]

Possibly someone damaged the busbar, or cut it to the wrong size - for example if it is a split load CU, or maybe bought the CU used or incomplete at a reduced price. You can usually buy new Busbars. If you can lay your hands on a digital camera and put a pic up someone will recognise it. Can you see the brand?

If MCBs are connected to the main switch by cable, it ought to be a pretty big size, not just 2.5mm

As regards having to turn off two MCBs to isolate a ring, what has quite likely happened is this:

Each Ring circuit has two ends, which are meant to go back into the same 32A MCB. Perhaps the installer, or someone making a change, has accidently mixed up the red wires for the two rings, and put one ground-floor end, and one first-floor end, into each MCB. This is a dangerous mistake, both in terms of electric shock (if someone thinks the circuit is off) and fire due to overload, since the circuit can draw twice the intended current before both MCBs will trip.

Although these errors are not especially difficult to fix, if you are not experienced in electrical work, and there may be other aspects of poor workmanship in the installation, you are probably best off getting a reputable local electrician, who is a member of a self-certification scheme, to inspect, test and rectify the installation. Try to get recommendations from friends and neighbours, but when you phone the electricians, ask if they are a member of a self-certification scheme, and which one it is. If they are, they will proudly say so and show it on their business cards, and will be able to issue you with an Inspection Report, or a certificate for any work they do.

 

[dek_d]

Thanks for the reply!
The CU is Clipsal with different MCB's in. The 100a switch is Clipsal and there are Hager MCB's and some without an obvious name, just what looks like a "P" logo.
I think I can now see why the Bus bar is not there. The MCB's that i do not know the maunfacturer of looks like they do not accept a Bus bar fitting? I may be well off here with my thinking but I pulled one out and it has a different connection type from the 100a switch and hager MCB's.
Is it ok to leave the looped wiring or would it be wise to replace the unbranded MCB's for some more Hagers etc and then use a Bus Bar?
If you need a picture, I'll get them posted.
Thanks again.

 

[Adam_151]

It looks like it has been thrown together from loose bits that were laying around, and either the clipsil busbar wouldn't fit, or he never had that part to start with, too be honest, replacement of the cu is probably the best course of action tbh

 

[dek_d]

I think I'll go with your advice and get rid, they seem to be cheap enough and I think it's a good prompt to get it up to a split load at the change. Thanks for the reply.

 

[Adam_151]

Unfortunatly, generally replacement of a CU is not usually a job for any but the most competant of DIYers, because of the issues with isolating it, and also the testing of it* you have already found one problem that needs attention (the muddled rings) so ideally you need a sparky to do the job, you can keep costs down by sorting out the muddled rings before you get a sparkie in though, because he will have to fix that as part of it** (or stick all four legs in one breaker!)

*though you could argue that you are not making it anymore dangerous than it is already, though you will be breaking the law if you don't notify the work, though if it was me, I might be tempted to fix the muddled rings and replace the CU and be happy that I've improved things

** I'd say its a code one, and you'd be stretching the purpose of the deviations box on the EIC a bit too far if you put a code one thats directly connected to the work you did, in there, me thinks