Only Offgrid!! New 12K Growatt System Questions

markansas said:

now from what i see is that they dont want you to go over 150volt dc input of the panels. growatt made two versions of this one rated at 150v dc and one at 250v dc.. check and see what you have please and lets go from there.. if you have the 250v dc input you might be able to redo your strands. if i am using the right words.. warning warning do not go over the voltage recommended..
mine

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He has the 150V version, one of the early ones.

Zwy said:

That answers that question doesn't it? No more than 3500w per input with a total of 7000w.

If I had ordered the GW 12Kw, I would have to add another SCC for my panels. With the LV6548 in tandem, I can have PV input of 4000w per input for a total of 16Kw of PV input. With my 530w panels, I can only go 4S per input as VOC is 49.65 and it gets very cold here. If I ever do a 2nd array, I think I'll put the 530's on a seperate SCC and run 385w panels with a VOC around 40. That would get me closer to the 4000w limit and still stay under 250V PV max voltage.

The newer versions of the GW 12Kw are 250V max PV input, not the 145V Ian has on his website. Sig Solar has the right specs. https://shop.signaturesolar.us/products/12kw-48w-240vac-120a-off-grid-inverter-by-growatt

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The problem is that many are stating over panelling does not hurt the inveters or scc. I have 4 scc plus two inverters and was told that both have no issues with being over paneled.

kromc5 said:

The problem is that many are stating over panelling does not hurt the inveters or scc. I have 4 scc plus two inverters and was told that both have no issues with being over paneled.

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And weren't you over sold panels by Sig Solar with the understanding from them it could be overpaneled?

MrM1 said:

And weren't you over sold panels by Sig Solar with the understanding from them it could be overpaneled?

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That is correct as there was no danger of overpaneling the inveters or charge controllers and that voltage was only concern. This was also again stated on the call today as well. They kept questioning about surges from the grid but I'm not connected. I have data showing its never gone over 140v and I sent data on the day the caps went out and it was showing 138.8v. I now have to come up with a way pull the 125 foot buried cable and add more.

Solar Newbee said:

Question on another note on the Growatt 12K Inverter. In wiring up this inverter to a breaker panel/sub panel for AC power, from the AC output when wiring for 240 volt, do you wire H1, H2, and the N/ground or not to the terminal in the sub panel/breaker panel? I looked at the user manual, and it show just the H1 and H2 to get 240 volt. For 120 volt it is either H1 or H2 with just the N/ground to a sub panel for 120 volt. Can someone clarify this for me. Thanks

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What did you end up doing?
Did you connect ground from both main panel and subpanel together to the AC input of Growatt and AC output neutrals as well?
The ground belongs to the AC input group while neutral belongs to AC output group.

@kromc5

I wired up the Ground, L1, L2 and Neutral from the AC OUTPUT to a panel in a shed to provide AC power in that shed.

alvirtuoso said:

What did you end up doing?
Did you connect ground from both main panel and subpanel together to the AC input of Growatt and AC output neutrals as well?
The ground belongs to the AC input group while neutral belongs to AC output group.
View attachment 80165
@kromc5

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I'm only connected to the main, and I used output h1/h2 and neutral is required also.

Solar Newbee said:

I wired up the Ground, L1, L2 and Neutral from the AC OUTPUT to a panel in a shed to provide AC power in that shed.

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Thank you for the response!
Did you have your panel in shed both wired to ground and neutral from inverter terminals or just the neutral?

This is referring to the panels question. I have a Growatt 12K 250 volt inverter. I run five panels in series All Summer Long with no problems. Equaling 10 360 watt panels on one array. Also had 12,360 watt panels running in a series of four. Did not have any problems until approximately till I got down till below 40°. These are 72 cell panels. I would say if you're running 60 cell panels five the series probably would be fine.

Going going back on the panel situation. I think that 250 volt is actually only capable of a maximum of 245 volts. I only seen a maximum of 251 volt when it was shutting down my controllers. I also had a situation with my app ever 200 volts unit 80 amps shutting down when the voltage was only reaching 196. I had to reconfigure that array to three in series instead of four. Must be these maximum voltage is have to be below that threshold. I think they suggest staying 20% below maximum voltage.

Bigblockcutlass123 said:

Going going back on the panel situation. I think that 250 volt is actually only capable of a maximum of 245 volts. I only seen a maximum of 251 volt when it was shutting down my controllers. I also had a situation with my app ever 200 volts unit 80 amps shutting down when the voltage was only reaching 196. I had to reconfigure that array to three in series instead of four. Must be these maximum voltage is have to be below that threshold. I think they suggest staying 20% below maximum voltage.

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What is the VOC max of each panel?

What is the operating voltage of each panel?

I believe the Growatt 250v (either in the stand alone charge controller or built into the 12kw inverter) is designed for 250v voc and an operating voltage between 60-245vdc and 3500w input per pv input according to the specifications.

Growatt has a told us not to exceed these amounts. See the last column (right) for the SC48120-MPV

You will never come close to 3500 watts with 4000 watts of panels unless you live at the equator. My open circuit volts calculates to 240 volts for 5 panels in series, but when it gets cold, the problem happens. It worked till mid November then overvoltage. 251 volts is the most I seen. I am Running 4200 watts of panels. The best output I seen is 3100 watts peak. Still below 3500 watts.

Bigblockcutlass123 said:

You will never come close to 3500 watts with 4000 watts of panels unless you live at the equator. My open circuit volts calculates to 240 volts for 5 panels in series, but when it gets cold, the problem happens. It worked till mid November then overvoltage. 251 volts is the most I seen. I am Running 4200 watts of panels. The best output I seen is 3100 watts peak. Still below 3500 watts.

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I had the 150v 12k over paneled with 3s which would hit around 132v. They ran this way for a good while. But then main 160v capacitors failed and was told it was due to over panelling or being to close the rated voltage. Growatt was very adamant about not over paneling and voc. I would not run a 5s and have voc that close to the maximum. The growatt inverter will not warn of any error, the growatt sccs will let you know when they are within 10v of maximum.

kromc5 said:

I had the 150v 12k over paneled with 3s which would hit around 132v. They ran this way for a good while. But then main 160v capacitors failed and was told it was due to over panelling or being to close the rated voltage. Growatt was very adamant about not over paneling and voc. I would not run a 5s and have voc that close to the maximum. The growatt inverter will not warn of any error, the growatt sccs will let you know when they are within 10v of maximum.

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From the horse, thru the horses mouth. YMMV

alvirtuoso said:

Thank you for the response!
Did you have your panel in shed both wired to ground and neutral from inverter terminals or just the neutral?

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I grounded the solar panel inside to the combiner box, and then from the combiner box to a rebar into the ground. I have a 300A surge protection from midnite solar wired into the combiner box. hope that helps.

I'm green as they come. I just put together my first battery for my 12k growatt.
16 - 304amp/hr cells, Daly smart 250amp BMS
I also collected an eco-worthy kit. I am using the 8-100 watt pannels, and the combiner box the kit came with. I provided pictures.
I have a 12k generator with 50 amp output that I will use to supplement charge when needed.
I am in an RV after house fire. I need 50amp for RV.
I ordered 2 outdoor 50 amp receptacles. One to plug in RV, and one to plug in generator for supplimental charge when needed.
I'm using 2 gauge welding cable to attach battery to inverter, and have a 250 amp breaker to run inline there.
In addition to 50 amp feed to RV I want 25 amp circuit inside the shed, as well as an additional 25 amp outdoor recepticle for power tools, etc. Maybe, the gfi for outdoor should have two 25 amp circuits, in case two power tools being used at once.
I would like to order a pannel off of Amazon, and anything else I may be forgetting. I am not sure what to order. A 200 Amp pannel. But there won't be many circuits.
Any suggestions for my solar shed would be greatly appreciated