Domestic 3ph consumer unit questions.

[Barking Mat]

One for the electricians amongst us....please.

So, I'm renovating an old house, it will have three bedrooms, and all the normal stuff, i.e. lighting, hot water tank, washing machine, etc... No electric heating.

I have 3 phase coming in, to the middle room of the house, where the counter is, but tommorow I want to move the fuse box to the back shed, behind the middle room. I have a three tier consumer unit, so I can split each phase to balance the phases, each phase protected by an RCD before it gets to the MCBs.

I have the schematics for balancing the phases, and understand the rest from there.

From the meter/counter I'm probably going ten to fifteen meters to the new consumer unit.

2.2 kW hot water tank, washing machine, tumble drier, electric oven ?kW, maybe a dishwasher one day?
Lighting, plugs and normal stuff. The workshop will be on a different feed from the counter, so this is purely the house.

What size cable from the meter to the consumer unit? 5g6 or 5g10? Or bigger? Surely not?

 

[dobbslc]

I'd say a minimum of 16mm probably 25mm, do you know what size the main fuse / cut out is?

 

[Luke]

Don't size the cable for the loads on it, size it for the protection before it.

If not, the cable isn't protected.

 

[Barking Mat]

I think I've got 25mm coming in from the transformer, hundreds of meters down the road.

@Luke, good point, 2x 40amp RCDs and one 63 amp RCD.

I'll go pick the brains at the electricians trade counter. Thanks

 

[Paulbarrett]

Or get a spark in!

 

[steviec_lj]

Personally, I’d match it with 25mm if I was doing it myself.

Although, as you’re messing with the service head, it’s probably best to get a spark in..

 

[knighty]

any idea what size the main fuses are ?


you might as well drop the 3 phase and just pick one to run to the new fuse box?

cheaper now, and cheaper later when there's less standing charge for whoever buys the house / lives there

 

[Barking Mat]

No, if I take a single spur on 220v I'll have to increase the contract of however many kilowatts I have coming in.
If I split the phases I can have all appliances running at the same time, hopefully.

Basically at the moment if you put the oven on and tumbledrier at the same time it trips out, if I split them on one each phase I think that should work.

5g16 x 15 meters = 130 euros.

Get a sparkie in? Where's the fun in that?

Thanks, more to come.

 

[knighty]

oops sorry didn't realise you're in france!

63 amps is 15kw

which at 15m you're ok with 10mm (according to the online calculators)

but I'd go 16mm like you say above, better to have a bit of head room

 

[brightspark]

I think I've got 25mm coming in from the transformer, hundreds of meters down the road.

@Luke, good point, 2x 40amp RCDs and one 63 amp RCD.

I'll go pick the brains at the electricians trade counter. Thanks

most are brain dead and only flog what u ask for

 

[dobbslc]

If you're in France then just make it up as you go along! It's OK .
Don't blindly follow eu rules like us mugs!
red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red yellow blue red etc

 

[brightspark]

would that be brown black grey and blue cant see the problem working with it all the time apart from some electricians cant get it out of there head the black is a live and not the neutral

 

[dobbslc]

Ok on new stuff but try tracing a blue neutral cable through a 6" length of trunking full of blue lives!

 

[brightspark]

Ok on new stuff but try tracing a blue neutral cable through a 6" length of trunking full of blue lives!

I have a cable tracer transmitter and receiver find them no probs it even traces cables 6 inch away from the probe through ceilings and under floorboards . dead cable tracer . https://www.test-meter.co.uk/socket...MI8ebAjOfB2AIVA8-yCh2jSAWSEAQYAiABEgKkqfD_BwE

 

[knighty]

I have a cable tracer transmitter and receiver find them no probs it even traces cables 6 inch away from the probe through ceilings and under floorboards . dead cable tracer . https://www.test-meter.co.uk/socket...MI8ebAjOfB2AIVA8-yCh2jSAWSEAQYAiABEgKkqfD_BwE

I've never seen one of those before.... you clip the clips onto one end of a cable, and then the detector can pick it out at the other end ?

 

[brightspark]

I've never seen one of those before.... you clip the clips onto one end of a cable, and then the detector can pick it out at the other end ?

one lead on the earth and other on conductor live or neutral and will pick the cable up anywhere along its length in a bunch back to source or up to where the break is or an individual fuse in a bank if ones broken .not used often but its good when your stuck

 

[GW8IZR]

I use mine most for chasing trailer electrics, very handy tool

 

[Westfield-builder]

most are brain dead and only flog what u ask for

Or what they have in stock and want rid of !