Solar quotes for our house

[Newcastle George]

Terry, I measured the grid voltage at the meterbox of the house at the front of the block which is approx 10 metres from the grid lines. At a guess I would say that the grid voltage is being dragged down by the number of air conditioners in the area working at full strength due to the outside temp being 41* in the shade. The solar output current is currently 22A.

George

[jon_d]

pretty good considering that panels derate in heat

[T1 Terry]

pretty good considering that panels derate in heat

Ummm.... one array is 10 panels @ 32.5v Vmp (STC) = 325v, the other array is 12 panels so a Vmp (STC) = 390v. To drop to 200v means the panels in one array derated its Vmp to around 60% output on a 41*C day and the other array to around 50% I wouldn't be in a rush to buy that brand panels if the heat affects them like that. Can you imagine the outcry if RV panels dropped from their 17v Vmp to 8.5v?

T1 Terry

[jon_d]

George said the AC volts is 200V, not the panel voltage.


I was commenting on these two points

1. The inverter has a max output of 5.5kW and 23.9a
2. The solar output current is currently 22A.

Which I have just realised are unrelated. oops.

[Newcastle George]

At 10:22am when I posted the panel outputs were: East 12 panels - 340.2V 7.5A, West 10 panels - 303.5V 4.9A.

George

[T1 Terry]

I have just noticed that the ACV output from the panels is 200V so on checking the grid voltage found it to be 198.5V so due to the low grid voltage and therefore low solar output volts the watts produced by the solar are drastically reduced.

George

I just read that as voltage output from the panels as it was different to the grid voltage.

[Newcastle George]

I have just measured the grid voltage again at the front house meterbox - 218V at 5:27pm. Terry, I did say AC voltage, not DC voltage.

George.

[supersparky]

George , at a guess I would say that a transformer local to you had dropped an input hv fuse and the measurements you are getting is just your supply phase voltage across a three phase transformer. Probably caused by, as you say, everyone running their airco. It's a bit hard to explain without being able to measure all three phases at the same time. We used to find it quite common after an electrical storm. I am surpised that your inverter did not shutdown due to the low grid voltage.

[Newcastle George]

Dave, our oven did shut down and I am now having trouble restarting it, Dinner was cooked on the BBQ.

George

[supersparky]

George , at a guess I would say that a transformer local to you had dropped an input hv fuse and the measurements you are getting is just your supply phase voltage across a three phase transformer. Probably caused by, as you say, everyone running their airco. Either that or it was just about overloaded ready to melt.It's a bit hard to explain without being able to measure all three phases at the same time. We used to find it quite common after an electrical storm. I am surpised that your inverter did not shutdown due to the low grid voltage. You are lucky your supplier didnt drop supply off to your area for a while. That is what Energex has started doing up on the gold coast and in Brisvegas.
Just found another way to double post while trying to edit. Sorry.