3 Phase Solar Installation

[carlyai]

Anyone installed 3 phase solar?

I'm still tossing up whether to do this myself as a project or get an installer.

I would like to contact people who I could get advice off.

I know there are people on the Electrical Forum who always help, but would be good to contact others on this forum who have DIYed it. Thanks.

[KhunLA]

Had 1 phase installed, so really can't help much, but would recommend, if looking to sell back to PEA/MEA, in the future, then make sure you use one of 'their approved' inverters.   The 3 phase Deye 10 & 12kW hybrid, I think, is on their list, so maybe consider.

 

One of the updated lists of approved inverters 

 

[tuk75]

Maybe this from Deye can give some ideas

[carlyai]

If you were installing 3 phase solar, would you go for 1 x 3 phase inverter, or 3 x 1 phase inverters.

I do have 2   3 phase water heaters but I don't have any 3   phase motors, so was thinking the phase difference would not be important.

[lom]

3 hours ago, carlyai said:

If you were installing 3 phase solar, would you go for 1 x 3 phase inverter, or 3 x 1 phase inverters.

That is a tricky question. I have a single 3-phase 12KW Deye inverter and there are times I wish I had bought three 1-phase inverters instead but I don't have the space for 3.. I do sometimes have a high load on one phase causing the inverter to trip (reset , restart after 30 seconds) if I run it completely off-grid. So I have instead to run it with grid-assist. You will probably not be affected by that if your water heater is 3-phase. It is also better for redundancy to have three 1-phase inverters instead of one 3-phase inverter.

If one of three 1-hase inverters breaks down then you still have the other two phases powered by solar..

[Crossy]

14 minutes ago, lom said:

If one of three 1-hase inverters breaks down then you still have the other two phases powered by solar..

 

This would be my thinking too.

 

We are only single-phase but are running 3 x Deye 5kW hybrids. Water heaters are on the grid side of the inverters so I can run them purely on-grid or via the grid-tie (zero-export) inverter function. Just open one breaker and everything except the heaters is off-grid.

 

[Pogust]

A bit late reply I'm afraid but didn't look in here earlier. I installed 12 kw of panels and a SRNE hybrid 3 phase inverter 3 months ago. Together with 42 kwh of batteries. I have all 3 phase in 3 houses.

Tried different setups. First with totally off grid and a ATS to connect to grid if needed. That wasn't so good as it is a manual switch and generate a short cut off that cause problems to some electronics like routers.

So set it up with inverter direct connecting to grid instead and switch when over the 4 kw each phase allows. Now I don't see the switch over any more. When I have 2 kw storage water heaters it seldom triggers the switch. Happened at Christmas when plenty of cooking, and sometimes when using welders but that's only short time. For the last months the PEA bill was about 90 bht.

So I don't really see a need for 3 inverters unless heavy long time use. A few hours of connecting to PEA for backup gets a lot cheaper than 2 extra inverters. And the less complexity in the system, the safer it is....

 

Just my thoughts about it...