Guidance for plug in solar for Electricians

I doubt if most people will bother asking.  Why would they?

If they are type approved, the new "balcony" solar inverters are intended to be plugged into any convenient socket on any socket circuit, whatever type of RCD is protecting it.

So the only question you should need to ask is "is your new solar system type approved for use in the UK?"

I can't believe a type ac rcd will be considered safe with solar connected.

Alan B said:

I can't believe a type ac rcd will be considered safe with solar connected

Perhaps a better query will become "Just how dangerous is that, in reality?", given the number that are likely to be installed on circuits without such additional shock protections?

We are in a bit of a cleft stick, between a rock and a hard place, on the need to decarbonise much faster than we currently are. This years heat wave is nothing special. Some hard and awkward choices were needed.

We'll probably have the same discussions next year for battery storage with these and similar units.

The more awkward discussion is between electrician and customer who actually asked for their circuits to be checked for whom the reduction in electric bills is critical (poverty), and spending all the savings on an upgrade is the last thing they want.

The only questions are

1) is it actually dangerous enough to worry ?

and

2) considered dangerous by who exactly ?

Given that missing an RCD altogether is perhaps a C3, depending where, then I cannot see an AC RCD that may or may not work being that much of a big thing,

RCDs go for years without firing in anger, and some go years without being tested either, and most will go to landfill having never been called upon to save a life. The assumption is that the lives saved by the ones that do pays for the waste of resources that are all the others.

Here we have to offset against excess deaths from climate change and there is rather more to play for - arguably in that context some increase in risk and some more accidents are a necessary sacrifice, as opposed to a more usual  knee-jerk  'one death is too many, do nothing' 

Also its plug-in solar, and nothing to do with fixed wiring any more than any other appliance,  so while an electrician may advise that these 2 sockets are on different circuits, the sort of thing that may be worth considering if multiple systems are installed, in many ways the problem of some dangerous product and 'is this wise' is out of scope.

I did note in another thread that the govt tender is out for the plug in battery consultation, so legislation for that is probably a bit under a year away and will no doubt be equally contentious, though by then plenty will already be installed before the deadline no doubt.

incidentally the no of plug in solar kits now approved for plug in connection has gone up a bit, but is not exactly many.

https://connect-direct.energynetworks.org/device-databases/search-gen?device_type_id=14

Mike. 

Alan B said:

The likes of Martin Lewis is recommending people should ask an electrician to check their installation before plugging a solar system in.

I am not clear why plugging in an 800 W negative load would be any more dangerous that plugging in a 3 kW positive one.

Alan B said:

I can't believe a type ac rcd will be considered safe with solar connected.

Is it any more dangerous than plugging in yet another gadget with a switch mode power supply? Our homes are now full of such gadgets, yet, from personal experience, a faulty appliance will still trip a type AC RCD.

I quickly checked the mini consumer unit that my rooftop solar is connected to. It's got a type AC RCD too. Things were different back then.

If you are giving professional advice it better be good and you should have appropriate  Professional Indemnity Insurance.

Does the socket comply with BS 1363?

Without it being a plug in solar inverter, it could be any appliance,  does the intended socket comply with 411.3.3? 

Does the socket meets the requirements of 531.3.1 to 531.3.4.2 and 531.3.6?

Where there is an upstream RCD of the RCD for the socket is it of a correct type and will selectivity be achieved in accordance with Regulation 536.4.1.4?

If the intended socket is on a heavily loaded circuit would the additional supply negate the overload protection for the supply cable, see the requirements of Regulations 551.7.1?

When tested is the polarity of the socket correct?

When tested is the socket earthed?

Does the RCD trip in the correct tripping time?

Provide your advice in writing and keep a copy for a 100 years just in case as society is very litegous.

Hope this helps?

JP

(grins..)

Isn't that the same advice as would be given for plugging in a TV?

Doesn't a negative load reverse time? Like an anti-ageing cream. If you apply to much you get ..[insert facetious consequence here] ? 

You have to hope that he negative load (aka supply) actually does collapse to zero load, as soon as the DNO supply stops providing a reference synchronisation signal, etc etc.

consumer : anti-sumer : pro-sumer

Or at least any garden appliance like a hot tub.

but yes.

An outdoor TV perhaps ? 

 All those things like is there no RCD, are L-N wired reverse polarity, is it off earth etc. are all issues that if undiscovered do increase risk. However, worrying about this purely in the context of one special type of appliance is not really helpful, except for it's one unique synchronous generation aspect. That is  the only way that things are different to any other domestic outdoor box with some electronics inside.

In reality, I don't think the folk fitting them will be that worried about the 'seek advice' part, or indeed the registration part. If Germany, land of "where are your papers" for everything, can only manage about a 50% registration, I fully expect both solar and battery  systems with all the wrong paperwork for the UK to spring up unannounced like mushrooms! They will of course bring with them new and exciting faults and compatibility issues until  the situation all settles down into something that folk treat as normal.

regards,

Mike.