Solar and Battery on Two Phase Installation

Qyburn

Hi,
Just wondering if anyone had direct or indirect experience with solar and battery on a two phase electrical system. It's a village hall so actually the final circuits are two sets of single phase 240V. They'd be looking for battery backup during power cuts, that's a major requirement.

I don't suppose for a moment that anyone does a two phase solar inverter so I think probably it would need to be two separate systems. Just wondering if there's a cleverer way.

Heedtheadvice

Indirect comments!

Non that I know of that are common in 'domestic' circumstances.

There are three inverter phase types:

Single phase very common in domestic and small commercial systems; relatively cheap.

Three phase for high power requirements and a costly price to match.

Split phase where the requirements is often for dual voltage outputs such as 130 and 240v

Two phase inverters are not at all common. They do exist but are quite complex and very expensive. A rare choice these days.

Your hall is probably just getting a dual feed for historical or power needs. Are you certain that you are getting two of the standard three phases?

Being two phases of the basic three electrical phases you need to ensure that the regs to keep them physically separated are copied with considering the much higher voltage between the two phases.....just a passing mention!

The best way of dealing with either  dual feed or two phases is to use the two separate single phase systems  for cost, choice and familiarity

reasons.

I still refer to the two phase comments above and would suggest a competent electrical engineer is used to ensure a compliant system is produced if it actually is two phases.

A quick online search produces several results such as Midsummer Wholesale that give some info and there will be experienced installers too.

Ectophile

Sounds like you need two separate single phase systems.  It's going to be easier than finding someone who does two phase.

Qyburn

Thanks. I believe it is indeed two out of three phases, confirmed when the electrician was quoting for generator backup. That was not uncommon in NE Scotland and one local joinery business said they actually has two-phase machinery as they couldn't get three phase.  I think it must only differ on the LV side from "normal" supplies like ours. We're fed by two 11kV conductors, two split off from the three that cross the fields a few hundred yards away. But our transformer gives us single phase L and N at 240V.

If it was just solar then I'd be thinking maybe we could just put it onto one phase. But for backup, I'm not sure if all the essential circuits are on one.

CuparLad

A quick look inside the supply cupboard should confirm what you have:

https://www.ukpowernetworks.co.uk/help/whats-the-difference-between-a-single-phase-and-three-phase-electricity-supply

Qyburn

Thanks I should be in the hall at the start of the month and will have a look.

Heedtheadvice

.....but that link's info will not tell you if two fuses are two supplies of the same phase ....or two out of three phases. Both setups would have two fuses but radically different voltages between the live wires!

paul991

measure it

Qyburn

Should be possible if I can find a live terminal from each phase. But at the moment I'm going by the electrician who quoted for generator backup.

QrizB

Qyburn said:

Should be possible if I can find a live terminal from each phase. But at the moment I'm going by the electrician who quoted for generator backup.

It might even be self-evident from the DNO cut-out. Share a photo!

Qyburn

Will do next time I get a chance.