2 consumer units - confused!!

JohnW2 · 10 May 2015

kevindgas said:
I don't need to pay for the EICR as I can do it.

With the best will in the world, I would imagine that a prospective buyer would be even less likely to trust an EICR undertaken by you than one undertaken by some 'independent' electrician commissioned by the seller's side.

However, as I said, it's really not for the seller (or a family member) to be organising EICRs - if a prospective buyer wants one, they should organise and pay for it.

Kind Regards, John

EFLImpudence · 10 May 2015

63A MCB on a 64A cable (method C) is fine - near the limit complies.

The only thing I would comment on, although not 100% clear, is that the heating system seems not to be all on the same circuit.

JohnW2 · 10 May 2015

EFLImpudence said:
63A MCB on a 64A cable (method C) is fine - near the limit complies.

Indeed. Even "63A cable" would comply - there's no requirement to exceed the requirements of the regs.

The conclusion that it is 'fine' obviously assumes that the whole run of the 10mm² cable is, indeed, 'Method C', and that no other de-rating factors apply.

Kind Regards, John

kevindgas · 10 May 2015

EFLImpudence said:
63A MCB on a 64A cable (method C) is fine - near the limit complies.

The only thing I would comment on, although not 100% clear, is that the heating system seems not to be all on the same circuit.

correct the boiler is dual powered and has a high 32A input for the heat element (10mm T&E) and a low 5A for controls (2.5 T&E) and is clearly marked as having 2 power sources

Adam_151 · 10 May 2015

If this is a domestic consumer unit, then is it suitable for a 63A breaker?. I've not yet come across one made for a CU. I have however seen plenty of 63A breakers from the same manufacturers commercial/industrial type A/B boards fitted to consumer units. E.g. Wylex PSB breaker used in a consumer unit otherwise populated with NSBs

JohnW2 · 10 May 2015

Adam_151 said:
If this is a domestic consumer unit, then is it suitable for a 63A breaker?. I've not yet come across one made for a CU. I have however seen plenty of 63A breakers from the same manufacturers commercial/industrial type A/B boards fitted to consumer units. E.g. Wylex PSB breaker used in a consumer unit otherwise populated with NSBs

A glance at the TLC site seems to indicate that Hager and Contactum both do them for their 'domestic CUs'.

Kind Regards, John

EFLImpudence · 10 May 2015

Yes, readily available.

kevindgas · 10 May 2015

the 63A is in the main house CU supplied from a 100A isolator switch with 2 6A lighting circuits on the same busbar separate RCD 30Ma has the 2 socket circuits and a cooker circuit in the same box
this feeds CU 2 in the extension

the 2nd has a 100A iso and 2 x 63A 30Ma RCD's supplying the MCB's

kevindgas · 10 May 2015

CU1 is a Hager and CU2 is a British General Nexus CU MCB's have been changed to suitable sizes but otherwise as supplied from BG Nexus

kevindgas · 10 May 2015

JohnW2 said:
kevindgas said:

I don't need to pay for the EICR as I can do it.

Click to expand...

With the best will in the world, I would imagine that a prospective buyer would be even less likely to trust an EICR undertaken by you than one undertaken by some 'independent' electrician commissioned by the seller's side.

However, as I said, it's really not for the seller (or a family member) to be organising EICRs - if a prospective buyer wants one, they should organise and pay for it.

Kind Regards, John

the issue is that each time Father in law gets a buyer some jumped up little prick builder comes looking for faults (that don't exist) puts the fear in the buyer who then backs out! happened 5 times so far but only twice has the elecs been questioned.
I want to be able to say with certainty it complies and get it endorsed by my local inspector (it will also count as my annual inspection

)

EFLImpudence · 10 May 2015

Just some things you haven't stated:

kevindgas said:
a smoke alarm circuit with 4 smoke alarms and 1 heat

6A ?

a outdoor power circuit 4mm radial supplying a double outside box and a shed (3rd consumer unit in shed) with 20A MCB to double socket(2.5T&E) and 6A MCB to a light (1.5T&E)

32A ?

An electric boiler 6KW max (running underfloor wet heating)

Is cable and OPD satisfactory?

If these things are alright then I would say it is over-engineered.

kevindgas · 11 May 2015

EFLImpudence said:
Just some things you haven't stated:

kevindgas said:

a smoke alarm circuit with 4 smoke alarms and 1 heat

Click to expand...

6A ?
Yes

a outdoor power circuit 4mm radial supplying a double outside box and a shed (3rd consumer unit in shed) with 20A MCB to double socket(2.5T&E) and 6A MCB to a light (1.5T&E)

Click to expand...

32A ?
Yes and 4MM SWA from extension to Shed.

An electric boiler 6KW max (running underfloor wet heating)

Click to expand...

Is cable and OPD satisfactory?
yes 10mm and 2.5mm as required by manufacturer (santon premier heat)

If these things are alright then I would say it is over-engineered.

better that than under!

securespark · 11 May 2015

Do you get discrimination?

Between 2nd CU and shed and 1st CU and 2nd CU?

kevindgas · 11 May 2015

Explain please? Not sure what youre asking?

ban-all-sheds · 12 May 2015

kevindgas said:
we built the extension and it is all but completed and signed off by Building Control

So how much of the electrical installation was associated with the extension?

Who did it?

Was the doing of it done in the way, and/or by the sort of person, that Building Control were promised it would be done when Building Regulations approval was initially sought?

Are you trying sell the house with an unfinished extension, or a finished one? If the latter then the completion certificate will include the electrics.

kevindgas said:
the issue is that each time Father in law gets a buyer some jumped up little p***k builder comes looking for faults (that don't exist) puts the fear in the buyer who then backs out! happened 5 times so far but only twice has the elecs been questioned.

How come so many potential buyers have been getting builders to come and look at the place?

I want to be able to say with certainty it complies and get it endorsed by my local inspector

If you did it, and you are not sure that it complies, then you should not have done it. There is no provision on an EIC for saying "having asked on the internet when carrying out the Design, Construction, Inspection & Testing, hereby CERTIFY that the said work for which I have been responsible is to the best of the knowledge and belief of people on the internet in accordance with BS 7671..."

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2 consumer units - confused!!

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