Pv EICR code

[Borderssparky]

Hi

We have just won a job to provide eicrs to a group of new build properties owned by a local housing association. (5 years old)

Each property is fitted with solis mini 1500 4g invertor in the loft for the pv installation.

Every single property appears to have a split load board. Hager Type A rcds and a 16amp mcb supplying the invertor.

Does anyone have an opinion on which code should be used here?

It's not a high integrity board, meaning no spare way to move the pv circuit.

 

[westward10]

So it is using a shared RCD?

 

[bill01803]

Going to be C2

 

[littlespark]

Morning, fellow Borderer.

Yes C2, unless it’s a bi directional rcd which I don’t think Hager does.

Are you tasked with the remedials as you go, or just report and see what they say?

Might be a case of taking the PV out the main board, splitting the tails and putting in a separate enclosure.

 

[Borderssparky]

Thanks for the replies.

It's a shared rcd yes. We havnt got the remedial works as yet. We start on Monday but a couple of the guys have popped their head in to houses throughout.

I think it's unlikely they rds will be bidirectional, the board will be at least 5 years old if the houses are.

C2 seems the right call.

How did they get away with this 5 years ago?

 

[littlespark]

5 years, you would hope there is an isolator to help with splitting tails.

Also think invertors in an attic are no go nowadays for fire risk, maybe a smoke detector up there?

Speaking of smokes…. Have they got the extra one needed in living rooms now? I know not strictly part of bs7671, but maybe worth a mention.


There are a ton of non compliant PV installs out there… from the early days when some company springs up with good marketing, throws them in with scant regard for regs and then disappears. Non sheathed t&e going into the PV meter is the usual one.

 

[UNG]

Yes C2, unless it’s a bi directional rcd which I don’t think Hager does.

It wouldn't make any difference if the RCD is bi directional as it is a split load board it would not meet the disconnection time for the other circuits associated with the RCD feeding the PV because of the invertor back feed and the shutdown time which would mean the disconnection time is exceeded, so it is a C2 no if's or buts

 

[littlespark]

Yeah. Spot on.

That’s what I get for posting first thing BC (before coffee)

 

[richy3333]

And there's also the issue of the consumer unit being rated at 100A but the 'theorhetical' total current could be more 100A+P.V. - assumed 16A?

 

[newfutile]

That's always confused me a bit, if your drawing 100 amps from the grid and the sun comes out at 16 amps,then you will only draw 84 amps.
If your still drawing 100 amps still you are really using 116 amps and the Consumer Unit was never big enough in the first place

 

[brianmoooore]

It will all depend on how the devices are arranged on the busbar. Different sections might have anything between 0 and 116A flowing through them.

 

[littlespark]

Highly theoretical of course…

If the PV is on the busbar as in this case, the 16A would be used up by the next closest circuit physically, and anything else taken out the 100A grid power.

The problem may arise where the PV is connected into its own CU, where the tails have been split…. So the full 116A would flow through the general board mainswitch, and the tails from the Henley block where it was connected.
16 from PV, 100 from grid

 

[baldelectrician]

I have noticed this on recent new builds around here

With Hager you can buy a bit of bus bar and a neutral bar / link and make the consumer unit configurable, this will allow a bidirectional RCBO such as ADC920G - 20A

RCBO 1M 1P+N 6kA C-20A 30mA A • ADC920R | Hager

Find products, Bidirectional RCBO 1M 1P+N 6kA C-20A 30mA type A and more on Hager United Kingdom

hager.com