RCD / RCCB upgrade due to additional load or seprate cicut

[andydeano777]

I have a Crabtree consumer unit which has a 32amp MCB and 40amp RCCB, feeding a 32amp load over a 2m run of 6mm twin and earth.

I now need to add an additional load of a further 16Amps onto this circuit, however this additional load may not coincide with the 32amp load.

Do I :-

A: upgrade the MCB and RCCD to 50Amps each

B: add the additional load on it's own circuit with 16amp MCB and RCCD ?

thanks

 

[ban-all-sheds]

What are these loads? Are either constant? Are they each either 0 or max?

You say that the additional load may not coincide with the existing - that also means it may.

RCCB/RCCD?

Thinking that you could use 6mm² cable for a 50A load?

Thinking that you should have an additional pair of devices (MCB + RCD)?


I appreciate that you have come here to find things out, but really you cannot do work like this just by asking whatever random questions happen to occur to you. You've already shown that you have some dodgy misconceptions - what if you get something wrong because you have no idea your knowledge is wrong? What if you miss something because you simply have no idea it even exists, and just don't realise you don't know it?


I strongly advise C: get an electrician.

 

[andydeano777]

They are both either 0 or full

Correct both loads could coincide.

It's definitely a RCCB (that's what has already been fitted by an electrician).

There is currently a RCCB+MCB to protect the current circuit. Simply asking if it would be better for the additional load to be on a separate circuit.

sorry forgot if option A replace with 10mm.

So far option C has quoted £600

 

[sparkwright]

As asked, we need to know what these loads are - ie what appliances are going to be served.

Cookers, for example, can have diversity applied which can work in your favour.

Would also be useful to know how this existing board is currently fed. Would be useful to know the cable size of that.

Of course, the best advice would have to be get some more quotes
.

 

[andydeano777]

I got an Electrician in, in the end as advised.

The Fuse was upgraded by the electricity supplier to 100A but tails remained at 16mm2 as less than 30cm to the meter. 25mm from meter to current CU.

The electrician has fitted a 3way consumer unit fed with 6mm tails with a C32 MCB and an RCCB 40Amp 0.03A (same as the setup already installed).

The loads are two electric cars which pull a constant load right up till about 95% charged and then the load drops off.

All work completed in a couple of hours and improved better than the previous quote so paid £419

Just thought I'd comment incase anyone else comes across the same predicament in the future.

 

[ban-all-sheds]

Who installed the circuit and connections for the first electric car?

 

[stillp]

The electrician has fitted a 3way consumer unit fed with 6mm tails with a C32 MCB and an RCCB 40Amp 0.03A (same as the setup already installed)

What rating is the other MCB?

 

[andydeano777]

Who installed the circuit and connections for the first electric car?

It was an electrical subcontractor to British Gas / Chargemaster, it was a free install as part of having the car. Sponsored by the government.

 

[andydeano777]

The electrician has fitted a 3way consumer unit fed with 6mm tails with a C32 MCB and an RCCB 40Amp 0.03A (same as the setup already installed)

What rating is the other MCB?

The other MCB is a Crabtree C31 61/C32

The cable to the charge point is 6m in length, 2m inside behind plasterboard and 4 m outside, run in 6mm. The car uses 32Amps. He said they are extreme;y busy at the moment with all the new EV cars recently been sold.