OpenEVSE & 3 Phase

I’ve invested in a large PV system at my son’s place - 3 Phase 30 kW max output.
My question is …
How to adapt an OpenEVSE Charging Station to run from 3 phase?


We have a 3 phase 40kW system. We charge a fork lift truck using just one phase same as we did before solar was fitted. Wouldn’t EVSE be the same. Isn’t a single phase system just a connection to one phase of the 3 phase mains. (In the UK)

Yes, but I think the implied question is, will the tariff meter charge for import on the phase with the charger if the other two phases are exporting? Obviously, if it is a Ferraris one, it won’t. If it’s an electronic one, it might or might not, depending (I suspect) on what the supplier has requested.

Obviously, the ‘better’ answer is a 3-phase charger that draws from each phase equally, and the ‘best’ is a 3-phase charger that’s balanced for minimum import on each phase independently. I suspect the first is probably available in continental Europe, the second sounds like a job for Robin. :grin:

[I couldn’t find the :tongue-in-cheek: emoticon.]

OpenEVSE is currently only available as single-phase. Although @chris1howell did mention at some point that a 3-phase version was in development?

There are plenty of 3-phase chargers available but I doubt they will have all the smart control and monitoring that the OpenEVSE has e.g.

22Kw 3-phase PodPoint:


1-phase and 3-phase EVSE are exactly the same on the controller side. You just need to replace the internal contactor/relay from 2 pole (L+N) to 4 pole (L1+L2+L3+N).

Yes your totally right, it will probable be a physical space issue to fit a 3-pole contactor relay inside an OpenEVSE.

@chris1howell do you know if any users have used 3-ph openEVSE? Might be worth search on OpenEVSE forums: Support : Support

So it’s contactor switching only, then? That would explain why I couldn’t see any power electronics in the pictures.

Yes if you search google images for 3-phase openevse you find lots of builds from Tesla and Zoe owners

The OP needs to tell which EV he owns, if the car does not have a built-in 3-phase charger there’s no way he can use all the available energy from the PV system to charge the car.

Yeah, lots of users have built 3 phase. cab123 is correct, the only difference is a 4 pole contactor. The selection of small 4-pole contactors is not very good in the US as 3-phase is only available in industrial settings.

Chris, do you mean physically small, or small as in low contact rating? e.g. 30 or 50 Amps.

Our new EmonEVSE unit supports three phase:

Glyn – Thx for the update – John (Banks)

I just found this 40A 4 Pole, and it’s really cheap.

I would highly recomend using a good quality contactor from a known brand. In my experience the unknown brand lower cost contactors fail after a short while therefore are a false economy. We used the following GC4040M5 from Schneider Electric contactor in the EmonEVSE. As a bare minimum it’s essential the unit is CE rated.

Chint is also CE. They seem to be widely stocked

They have a UK web site

Thought I would get one to try. Fits in the standard OpenEVSE box ok.

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