Solar Installation / Consumer Unit

[DurhamSparky]

Been asked to improve the installation of a domestic property prior to solar been installer (rent a roof scheme).

any way box needs replacing but seen as this impending installation is going to be installed, what requirements does the customers CU require.. is it just a spare way or does any thing else need to be fitted..

im trying to maximise the job and save the customer hassle when the "free" solar monkeys descend on her door!!

I have seen a box by wylex that's designed as a PV CU but i think its just a unessential waste of money!


steve

 

[moggy1968]

I would fit a split load 17th edition CU fitting the solar on it's own non RCD way. If an RCD is required for other reasons under 7671 then you have the option to use an RCBO on that unprotected way.
The solar must not be on an RCD shared by any other circuits.

 

[infinity]

your probably find a team will install a 2 way ccu anyway to keep the two installations seperate to prevent any come back on any faults with the rest of the property!

 

[DurhamSparky]

cheers lads..

i will indeed fit a 16A mcb on the Unprotected Way of the DB and am running to a FCU (etched SOLAR) for them to connect into rather than disturb my nice neat box...!

just forward thinking!!

 

[moggy1968]

you could split the tails into a henley block and fit a little shower unit or garage board with a 16a breaker next to your new CU if you want to keep it seperate.

 

[yellowvanman]

If it was done as part of the install then this CU change could be charged at 5% VAT as well - giving the customer some more saving!

 

[DurhamSparky]

dont charge VAT... so 5% cheaper still....!

 

[poheZ]

yes but you have already paid the VAT on materials

 

[valet]

My 2.5 kw system picked at 3499w. I have found that's fronius 30 ig plus is actualy 3600w max from panels. System In hot climate of oz and carib.

 

[GaryM]

cheers lads..

i will indeed fit a 16A mcb on the Unprotected Way of the DB and am running to a FCU (etched SOLAR) for them to connect into rather than disturb my nice neat box...!

just forward thinking!!

Your FCU will be rated at 13A maximum.
If you want to forward plan then you would be better off running radial protected by a 16A MCB to a 20A rotary isolator, using 6mm2 conductors as some inverter manufacturers insist on 6mm2 for certain inverters.

 

[GaryM]

I would fit a split load 17th edition CU fitting the solar on it's own non RCD way.

It's the manufacturers that are primarily guilty of referring to a consumer unit with 2 RCD's as a '17th edition consumer unit' but there really is no such thing.
A standard non RCD consumer unit can be compliant if you load it with RCBO's, as can a split load consumer unit where half of the circuits would be protected by the RCD and the other half by RCBO's. So, by design, these are also '17th edition consumer units' if you like.

What you're referring to is a high integrity twin (or split) RCD consumer unit.

 

[moggy1968]

sorry, your correct, got my terminology mixed up, I meant a high integrity unit (it was late!)
Had an argument in my suppliers the other day along these lines. Initially he didn't understand what I meant when I asked for a high integrity unit and gave me a standard split load board (twin RCD), then he said they weren't 17th edition compliant as they didn't have an RCD on the unprotected ways. I suggested he look in the regs book as not all circuits actually need RCDs

 

[yellowvanman]

I suggested he look in the regs book as not all circuits actually need RCDs

They are only shopkeepers!

 

[GaryM]

when I asked for a high integrity unit and gave me a standard split load board (twin RCD), then he said they weren't 17th edition compliant as they didn't have an RCD on the unprotected ways.

You should have asked why they stock RCBO's then!

 

[moggy1968]

it did occur to me, but figured I had given him a hard enough time!!

 

[moggy1968]

They are only shopkeepers!

had the same argument with one of the electricians on those multiple installs we were working on together Kev. He insisted that under 17th ed everything had to be on an RCD and refused to listen when I tried to explain he couldn't put the PV on a shared RCD. NOt sure if you met him, he didn't stay long!!