rough cost of replacing consumer unit, suggestions for extras?

I need to have me 1960s fuse box replaced by a modern CU. The meter is modern with modern tails. I think this is not a DIY job for me. I don't have part-P and I imagine there are lots of regs to be aware of.

I want separate RCDs on the five circuits (ring up, ring down, lights up, lights down, cooker) and slots for 2 more circuits to be added later. Transformer for doorbell.

I want a big DP (non-RCD) switch to isolate the whole CU.

1) How much should I expect to pay for this?

2) Does anyone have suggestions of what extras to include when I am doing this? Things you wish had been done when your CU was installed but weren't?

thanks (and sorry if this is OT),

Robert

Reply to
RobertL
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I had mine replace last year with a twelve way split load CU. Total cost

400 pounds. Only thing I wish I had thought about was to have a separate circuit for a mains powered smoke detector. Other than that, because I had done all the wiring prior to installation I have yet to find anything that I wish I had had done at the same time.

Andrew

Reply to
Andrew May

Separate RCDs will be RCBOs. These are quite expensive. Not considered a good idea to use RCDs on lighting circuits, and not necessary for a cooker. Might want another non-RCD circuit for things like fridge/freezer/central heating.

Get a CU with about 25% spare ways, and fill them with spare breakers rather than blanking plates. You may find you can't get matching breakers in the future, and they aren't very expensive.

Reply to
Andrew Gabriel

Very good points all, thank you.

Robert

Reply to
RobertL

I did mine the other wee.. ..I mean year and it cost me =A370 for a split load CU. The rest was just my time which I guess was an afternoon.

Reply to
adder1969

,

I would look into the question of MCB's and failing bulbs. I suspect that's because my CU - self replaced - is a cheap one and it may be that better quality MCB's are less prone to dropping out when bulbs fail, but it is a generally known problem and will either be answered here by someone who knows an answer, or you will need to search back posts.

RCD's and the lighting circuit are not generally recommended - however I have seen on these pages that the 17th Ed of the regs will encourage the use of a higher rated general RCD for the whole house. At least that is my understanding / memory of what has been said. Again one hopes that someone with better knowledge will happen by to give chapter and verse.

Rob

Reply to
robgraham

But required for a cooker if the cooker switch also contains a 13A socket.

Andrew

Reply to
Andrew May

,

I have what I hope is a decent quality CU (Crabtree Starbreaker) and the breakers do trip on every bulb failure.

SteveW

Reply to
Steve Walker

That's a very good reason not to use a combined switch/socket.

(Strictly, it's only _required_ if the socket is likely to be used to feed an outdoor appliance, but I personally regard RCD's as mandatory for all sockets in which portable appliances might be routinely used, and with that one being the classic kettle socket, particularly so.)

Reply to
Andrew Gabriel

It's not down to the quality of the CU, but is rather more related to the fault impedance and MCB tripping characteristics. I fit 6A type C MCBs for lighting circuits -- they may be slightly less prone to such tripping than type B, but are certainly not completely immune. Another option would be to use 5A BS1361 HRC cartridge fuse carriers for lighting circuits. However, most of the homes I know are rapidly decreasing their use of filament lamps, and that solves the problem too.

It's too new for any practical experience yet. Part P may still explicitly cite 16th edition anyway (certainly the first version did).

Reply to
Andrew Gabriel

I find it surprising that cookers are exempted as they are one area of major electrical exposure where heat, fluids, etc have a deleterious effect on insulation. The only way often enough that you are going to find that degradation is via an RCD and that is going to trip well before the insulation fails so much that the cooker becomes dangerous.

It may well be inconvenient to have the rcd go every time you switch the oven on for example, but it is an indication of a fault which requires to be rectified.

All the more justification in my opinion for the whole house RCD !

Rob

Reply to
robgraham

A colleague of mine had his CU replaced a few years ago, and the sparks installed a battery-backed emergency light (like an emergency exit light) in the same cupboard, so that you'd at least have some light to work by if something went wrong at night.

- Ian

Reply to
Ian Chard

That's if the battery still works by the time it's needed. ;-)

Reply to
Dave Plowman (News)
17th Ed of the regs will encourage CD for the whole house?????

Srely not:- if something trips out an RCD at night I dont want all the house lights going off!

[g]

Reply to
George (dicegeorge)

The point is that if the insulation does fail, a cooker is still extremely unlikely to become dangerous even without an RCD. Electrocution risk is mainly from portable appliances, even more so those used outdoors. Fixed and stationary appliances don't represent a significant risk.

No -- many of the insulating materials are hygroscopic (absorb moisture). After a period of no use, the leakage can be high and this is not considered a fault. The PAT test guidelines explicitly say you should allow such an appliance to heat up to drive off the moisture if it leaks cold. Of course, you can't get it to heat up if it trips an RCD the instant you switch it on.

You want the whole house to go out due to a non-fault in your oven?

Reply to
Andrew Gabriel

I've got a number I picked up from work when they were swapped out due to battery age. They were 5 years old when I got them, and that was 5 years ago, and I still get the full 3 hours.

Reply to
Andrew Gabriel

You could, I suppose, have the lights on a separate RCD to the rest of the circuits.

Reply to
Frank Erskine

The way things were pointing at an IET seminar prior to the release of the 17th were for a significant increase in RCD/RCBO protection requirements (It might be a good idea to buy shares in Hager and MICC manufacturers). All domestic sockets, (upstairs and down - the presenters in Birmingham were anguishing about relying on labelling for sockets intended to be dedicated to such as fridges under worktops), All circuits in bathrooms (which includes the light but if main equipotential bonding present supplementary bonding may be omitted). I recently came across a Hager 6A type B RCBO which would solve the bathroom light protection problem. Zone 3 disappears from bathrooms and 230volt RCD protected sockets.allowed if more than 3metres from edge of zone 1. The disconnection times for socket outlet circuits are reduced to 0.2 seconds which will make life difficult for a type S RCD in a split board serving a freezer socket on TT supply, Cables in partitions with metal components require to be inside earthed metal (Conduit or MICC), My copy came yesterday so I am still reading and digesting ready for a

16/17th crossover test hopefully next week if I can complete my read- through. Ho-Hum
Reply to
cynic

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember robgraham saying something like:

Agreed on that.

Not imo; better to fit an RCBO to the cooker supply and keep the lighting on non-RCD circuits. Why risk a broken leg in the dark when all the lights go out because of a faulty appliance, as would be the case with a whole-house RCD?

Reply to
Grimly Curmudgeon

Hi, Local electrician just finished mine this afternoon. I paid =A3420 plus =A337 for the supply company to come and fit a switch between their supply and the cu or maybe just reseal the supply he opened. This is for a 14 way cu with rcd on the garage and power circuits as suggested. He did insulation tests and other tests on the wiring some of which was from the sixties. And checked lights and switches for earth presence....relabeled everything and explained as he went along. The price without the circuit tests would have been =A3375. Another man quoted me =A3350 but I felt he was not such a good communicator and I wanted to understand more of what was happening. It took him about 1 2/3 days but he admitted he might have done it in a longish day. I was pleased he did not rush it. Good luck David

Reply to
gilli

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