@Backbone Energy

I have a medium-size unit in an estate where the supply is still 3-phase from when it was a big, older JHB property long ago. I had an old 5kw Axpert for my essentials fed by Phase 1, with the other circuits (geysers, AC, underfloor heaters, oven, erc) feeding of a mixture of Phases 1 to 3.

Now I am replacing the Axpert with a 5kw Sunsynk, and would like to supplement my non essential load on the grid side with my excess PV. But given I have 3 phase supply and some of the non essential heavy draw items are on other phases, does this mean I can only supplement non essentials that are on Phase 1 which feeds my inverter?

Also, does that mean the CT coil should be place of the Phase 1 grid feed to my DB, with no CTs on Phase 2 and 3?

Ideally it would have been nice to be able to supplement all my non essentials, but if I understand correctly, that means I’d have to move everything onto Phase 1. Not sure if that would be possible/ advisable, considering things like load balancing, and the rating of my Phases? (see pics)

I typically have an essential load of between 500w - 3000w, depending on what I switch on. Non essentials not on the inverter load include things like 2x4000w geysers, 3000w water pump, 2x4000w underfloor heating, 2500w oven, 3x1000w AC units. Obviously not normally on all at the same time, but theoretically possible.

Could I consider moving everything onto 1 phase only?

Hi there and welcome.

Yes you will only be able to supplement the phase connected to the inverter. Ct on the same phase supplying the inverter.

I would think that you will need permission from the estate to do any changes?

If you have prepaid the meter will have to be changed and the supply side will have to be rewired to single phase.

Thanks @Jacques Ester much appreciated 👍

I don’t have prepaid and fortunately I have full title over the property, so wouldn’t need estate permission. 

 

Ok. Then you can get an electrician to rewire and split your db for essential and non essential. This will allow you to install a single phase inverter or you can keep the db as 3 phase let them split between essential and non essential and install a 3 phase inverter.