New consumer unit

I would like to upgrade my consumer unit so that I have a few more fuseways and RCD protection on some circuits. The main electricity company fuse is a 60 amp one, and the current CU is rated at 60A. A quick perusal of the Screwfix catalogue does not reveal anything suitable rated at less than 80A. Am I OK in using an 80A CU without having the whole supply upgraded?

Thinking about this I presume that the fuse is there partly to protect the CU, so having an underrated fuse is OK in that the fuse will blow before the CU bursts into flames, please tell me if this is faulty logic.

I have a fair bit of DIY experience in wiring in new sockets and lighting circuits - is replacing the CU a suitable DIY task, would you say? The wiring doesn't look like rocket science to me, but is there post-installation testing which should be done (in which case I'll just call in a pro).

Many thanks,

Martin

Reply to
Martin Pentreath
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Did exactly the same myself last year, i.e. replaced two CUs of dubious antiquity with two shiny new units fitted with MCBs, one supplied via RCD and the other not. Life was made easy by the presence of a Henley block thus allowing safe-ish disconnection of meter tails.

BOL Richard

Reply to
Richard Savage

| > I would like to upgrade my consumer unit so that I have a few more | > fuseways and RCD protection on some circuits. | | > I have a fair bit of DIY experience in wiring in new sockets and | > lighting circuits - is replacing the CU a suitable DIY task, would you | > say? The wiring doesn't look like rocket science to me, but is there | > post-installation testing which should be done (in which case I'll | > just call in a pro). | >

| | The main question to ask yourself is, how are you planning to isolate | the supply cables into the CU while you swap things over? | |There is no reason however why you shouldn't do | the swapping-out yourself and then ask someone with the appropriate | knowledge and test kit to check it out when you have finished.

As I'm slowly (far too slowly) rewiring my house I'm running both the original horrid consumer unit and the new shiny RCD protected one that I've installed myself. The main problem I had with the installation was isolating the tails coming from the meter so I could split them with a Henley block. In the end I decided to be naughty and cut the 'seal' that was attached by the electricity company to the mains fuse, this itself was fine, but when it came to pulling out the fuse itself, I'd say it was the second most hairy thing I've done involving electricity, the first being putting the thing back in!

Wiring the whole lot in was fine and dandy, just cutting off the electricity in the first place that caused problems...

Seri

Reply to
Seri

That was tricky on a recent CU swapout I did for my daughter. Everthing was easy except when I pulled the main fuse the holder came away from the rotten chipboard it was mounted on.. not only that but the cable into the fuse had horrible rubber insulation that all disintegrated.. Downstream of the fuse the wiring was modernish.. Anyway I carried on and connected everthing up with this slightly dangerous setup... then phoned the elec company who took 3 weeks to get round to sending the right bloke who could sort it out.

Reply to
BillV

Standard practice here, assuming that you intend the new unit to completely replace the old one eventually, is to run the old unit from a spare way in the new one - you might want to move the "heavy" circuits to the new unit first, but it's surprising how little current you really use most of the time.

It helps if you've turned off anything downstream first - if there's no current being drawn then there's no risk of big sparks :-)

All you have to contend with then is the huge inviting live terminal, minimally shrouded, from which you have just pulled the fuse...

=:-O

Hwyl!

M.

Reply to
Martin Angove

Remove the fuse from the fuse holder, (2 screws on mine), then re-insert the empty fuse holder and all live parts should be safely out of halms way once again. [Having said that I was quite scared when I first removed mine - I'm sure it's just the fear of the unknown!]

Reply to
Mike Hall

It is also a good idea to fit a mains isolating switch if you have the space. This will save having to remove the board's fuse in the future if you need to isolate the consumer unit etc.

I did this when I installed two new CUs. Removed the board's fuse Fed the wires from the meter to the isolating switch Wires from the isolating switch to a Henley block Wires from the Henley block go to the CUs

I can now work on any of the consumer units by simply switching off at the mains switch, removing the wires to the relevant CU, and switching back on again. Saves having to remove the wires from the Henley unit live as I did in the past :-)

Roger

Reply to
romic

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