Isolator breaker resistance

AlanH said:

8.2A per panel. Yesterday it wouldn’t have been even half that with the weather we had. Today is a better day and it is reading fine. I haven’t had an issue previously. Its because I have been trying to implement a breaker.

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Bud Martin said:

Is this the correct user manual for it?

Growatt

Startup Voltage is 150VDC for the unit to start running but you have 3s for the panel which is about 120V.
Max PV input current is clipped at 22A and you have 3s6p with Isc of 9.37A 8.22imp per panel, so no way you will see 40A at the input of the controller.
You also say the controller works fine if you bypass the breakers, so how much charging current, PV input Voltage are shown on the contrller display.
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Bud Martin said:

"Panels are 3 in series with 6 parallel" so 18 panels total, 250W x 18 panels = 4500W of panels.
3s string is 8.2A, so 6 strings in parallel = 8.2A x 6 = 49.2A
The unit will only utilizing 22A max. current.
So What is the charging current you are seeing and how much power it is reporting?
You should put more panels in series to get it above startup Voltage and less parallel for less current to utilize more panel power.

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Bud Martin said:

"Panels are 3 in series with 6 parallel" so 18 panels total, 250W x 18 panels = 4500W of panels.
3s string is 8.2A, so 6 strings in parallel = 8.2A x 6 = 49.2A
The unit will only utilizing 22A max. current.
So What is the charging current you are seeing and how much power it is reporting?
You should put more panels in series to get it above startup Voltage and less parallel for less current to utilize more panel power.

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AlanH said:

“3s string is 8.2A, so 6 strings in parallel = 8.2A x 6 = 49.2A”

Well this is what I said.

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AlanH said:

Currently 100vdc and the controller is reading it.


So you think this has something to do with the low voltage reading between the breaker and the controller?

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Bud Martin said:

Well, but the SCC can only handle 22A of panel current, so how much power are you seeing from your setup without the breakers in place?

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Bud Martin said:

Is the 100V reading when you bypass the circuit breakers?

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AlanH said:

Bud, at first I thought the sheet you posted was the same as in my manual. It isn’t. Here is mine.. Why there is a difference I have no idea. With 22A on your sheet, I thought I was going out of my mind considering my series and parallel.

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timselectric said:

I don't see any PV amperage on your sheet.
Just charging amperage on the battery side.

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740GLE said:

So much half information and quasi answers.

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timselectric said:

Still just battery charging current.
I wonder why PV current limit isn't on the same page.

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Bud Martin said:

i do not see the PV input max current either, only the output current that Solar charger can supply to the batteries, is your case, 80A.
Can you give the link so I can download the user manual that match your controller? Thanks! may be also provide the picture of the sticker on the side of the unit too.
Max Voc is only 145V, wow.
BTW, I still like to know how much power your controller is reporting when breakers are bypassed, 3000W or so?

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Bud Martin said:

i do not see the PV input max current either, only the output current that Solar charger can supply to the batteries, is your case, 80A.
Can you give the link so I can download the user manual that match your controller? Thanks! may be also provide the picture of the sticker on the side of the unit too.
Max Voc is only 145V, wow.
BTW, I still like to know how much power your controller is reporting when breakers are bypassed, 3000W or so?

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Bud Martin said:

Thanks for the manual and the picture of the sticker.
If I read the manual correctly, your unit can have up to 80A of PV input current and use 6 gauge wires (as you told me earlier).
But the main problem we are trying to find out is why you have >100Vdc on the input side of the breaker but only 25 ~35VDC on the output side of the breaker going too the controller, I am not sure what is really going on there.
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