Hi all just had a new combi fitted for my mum in the kitchen of her small 4 room bungalow which feeds the sink only in that room the pipes all copper then go into the ceiling which are then all plastic to the bathroom and then back into copper which feeds the hot to bath and WHB and the towel rail, the cold is supplied direct from the mains pressure water which comes in from the bathroom and supplies the bath WHB WC and combi all in copper. The mains water in is earthed and runs to the fuse board, the property seems to be earthed with a rod in the ground going into the a small block near the fuse board then into the board where the earth wire for the water goes, I have been told that the new gas now needs to be earthed which I understand but what about all the other pipe work does this need what they call cross bonding or not as some of it is in plastic or is it just the mains cold in to the bathroom that goes to the bath and WHB only that need cross bonding, sorry for the long thread but any advice would be great as want to ensure mum is safe.
does mums consumer unit have RCD protection on ALL circuits ??? And if so has an electrician tested that RCD /S work as should ( disconnection times etc), recently ?
Hi Terrymac, there is one RCD in the middle of the unit with all the wires going to the left hand side of this and marked up with cooker, kitchen ring and lounge/bed ring which only has 7 wall sockets and the kitchen only has 4 sockets plus the boiler, the lights come from the other side of the RCD if that's any help not sure if the RCD has been checked recently.
If you have a TT earth (rod), you should have RCD protection for your whole installation. You should then also have main protective bonding to the gas and water services, but not to each and every pipe. Cable size would need confirming too. Photos?
as lectr said above. my advice to you is to engage an electrician ,with a view to upgrading the cu. your mums board only has RCD protecting some circuits . he will also ensure earthing is up to spec and will do all testing .not a diy job I am afraid .
Hi Lectr/terrymac, I have added a few pictures as to what's there now there also seems to be another circuit breaker where the mains go into before going into the fuse board I did make a mistake in my other comments saying that the wires went to the right in fact they are to the right of the RCD if the lighting was moved to this side as well would that mean all the circuits are protected?.
the lighting circuit is not connected to the RCD on your cu, so if the RCD trips because of a fault on any of the circuits it protects ,the house lights would still stay on. on new cu 's there are 2 RCDs lights would be on one .I am looking at pics on phone and not the clearest , but it appears to me that a couple of the cpc's may not be connected properly and the main earth cable looks too small . as I said b4 ,get a spark in.
The plumbing sounds like a dog's breakfast, you cannot rely either on good electrical separation or continuity, so the only answer is to ensure supplementary bonding is in place, and the main bonding. The service point looks a mess with the old Chiltern Fault Voltage Operated earth leakage breaker, now no longer accepted, I assume this is just being used as a main switch as I see no main earth going in or out. This appears to be a rural supply being TT, I would advise that an Electrician takes a look at this and tidies it up and checks the bonding.
If, as you say in your post, the main earthing system is via an earth rod, known as TT, that CU was never compliant anyway!!! All circuits on a TT system should have 30mA RCD protection purely on safety grounds. The 'old' way pre 17th edition, was for lighting circuits to be on a 100mA time delay RCD but that has been superseded and ALL circuits, especially on a TT system, should have 30mA RCD protection. You could apply for PME earthing to see whether it is available and you could get your CU upgraded, which would be metal now. The main earth cable on a TT system only needs to be 6mm2 so ignore comments about undersizing. If you had your earthing upgraded to PME then it becomes an issue and needs to be a minimum of 16mm2. Cross bonding of boiler pipe work is no longer considered necessary as long as your main bonding is in place for your water and gas service pipework. A cursory glance of your CU shows no evidence of main bonding anyway so I would definitely get a good electrician in to advise you about the earthing arrangements as a whole.
From what I can see you have an old voltage trip there. These where outlawed years ago. You then have a splitload board! Which means the v trip should have been removed at the same time splitload was fitted. In which case the no rcd protected circuits are relying on an earth rod. This is not correct! Time to get an electrician in prnto
Looks to me like a type E Chilten RCD. Not sure of the tripping current though? Oh and there's nothing in the Regs. stating all circuits have to be on a 30mA RCD.
Hi, I had a related question regarding earthing if anyone can advise please. I'm planning to have my old 'rewirable fuse type' fuse box replaced with a new consumer unit with RCD protection. The quote I had from an electrician included £80 for supplementary bonding in the bathroom. From reading the 17th edition wiring regulations, it seems to me to suggest that if all circuits in the bathroom are protected by a RCD, then supplementary bonding is not required. I only have a lighting circuit in the bathroom, no electrical sockets. Would my interpretation be correct?
Perfectly correct. If main protective bonding is present to gas/water, and all bathroom circuits are on an RCD, no supplementary bonding is required.
i can't help but wonder if the CU was a DIY install. given the mess of cables. i'd be embarrassed to leave it like that...
That photo screams a DIY install by a shed selling an off the shelf fully loaded 16th edition board and they still require us to jump thru flaming hoops What a rats nest Get a spark in to sort out that mess, pay him for his job
dya think so, I would say so, thats DIY for a fact, no spark would leave a job like that, prob the OP did it and is now asking the questions
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