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PV configuration for 3 growatt spf 5000 es

Billybob16

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Sep 27, 2021
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I'm trying to decide what would be the best PV configuration for my 3 spf5000es inverters.
I currently have 16 Aptos 440W VOC 49.9V Imp 10.47A configured 8/s in to 2 of 3 spf5000es inverters with 6 lifepo4 battery's.

I'm adding 12 solarever 445 Watt VOC 49.05 V Imp 10.89A. I'm needing a little advice if the below configuration would be the best way to go. I will have 3 arays, 1 to each inverter.

Solarever 8s1p 392 VOC 21.78 Imp
Aptos 8s1p Solarever 399.2 VOC 21.63 ImpA
Aptos 8s1p Solarever 399.2 VOC 21.63 Imp

My panels are 320 feet from my inverters connected with 3 pair of 8 gage stranded coper wire. I realize I will have some loss (aprox 3%) with that run but I think it should handle the add current from the paralled panel. Im trying to make best use of all the panels. If I series 10 solarever I'm over VOC (490.50) so I'm thinking 8s1p. What do you you all think?

I read in o e post that 330 Volt 18A is a sweet spot for this Inverter.

I have been running this system for a year now with the Aptos 8s x2 with only a few glitches that require reset of inverters. Inverters are tied to AC, set SBU, It's like they loose bms com and drain battery's before switching to AC. That has happened 2x now. I just updated inverters to see if it would help.
..
 
You have 16 panels and adding 12(28)
You are suggesting 3x8(24) - does it mean you retire 4 panels?
If you live in a place with warm weather all year - you can probably get away with 9S1P.

Either way with your distance between the panels and Inverter - I wouldn't parallel any and keep the voltage as high as possible (8 or 9S1P).

What batteries are you using?
 
I'm hoping to not retire any, I should have stated 9s1p for the solarever aray producing 441.05V that would use all the panels. Or I could not parallel any, run 3x9 and retire one or 9s1p 9s 9s.

I was thinking if it is true that the sweet spot for the inverters is around 330V 18 A that a 8s1p would be better.

I have 48 volt batteries, 5 EG4 lifepower and 7 EG4 LL V2. I'm still working out how to use the BMS com under LI control. I was told by SS to run the master lifepower in to com of master LL V2 then run master LL to growatt inverter setting 36 com to 54.
Jury is out on that.

Thanks for your reply
 
I'm hoping to not retire any, I should have stated 9s1p for the solarever aray producing 441.05V that would use all the panels. Or I could not parallel any, run 3x9 and retire one or 9s1p 9s 9s.

I was thinking if it is true that the sweet spot for the inverters is around 330V 18 A that a 8s1p would be better.

I have 48 volt batteries, 5 EG4 lifepower and 7 EG4 LL V2. I'm still working out how to use the BMS com under LI control. I was told by SS to run the master lifepower in to com of master LL V2 then run master LL to growatt inverter setting 36 com to 54.
Jury is out on that.

Thanks for your reply

With the 300ft+ to the panels you are not in a position to find that 'sweetspot'.
Better if you keep the voltage as high as the conditions allow you (9/8s).
Some users would go with 8 for the reason of not getting to close to the mppt max as it could damage it. Again depending on your weather.

About the batteries generally you are not meant to mix battery types.

Please give more information on the batteries issue, you mentioned it happened two times in what time period?
Can you take a photo of how you wired them

I have 0 exp with these EG4 and lucky for you they could give you support for that.
 
After more research and checking inverter distance from aray, correction it is only 130 ft. #8wire. Also looking at inverter specifications it says mppt range is 130v to 430v. I'm not familiar with this limitation and assume you want to stay under that 430v. What happens if over that limit for a short time?

I'm not sure if max VOC would ever be seen, calculating it with 9/s Aptos 49.9VOC and -29c coefficient at 20 degrees comes to 407.9V which would work just fine then parallel one panel, so 3x9s one aray would have 4th panel paralleled. (they say to use lowest expected temp when calculating, I dont understand why as voltage goes up with higher temp)

Anyone know what's the correct way to figure this to maximize output safely? I'm still trying to figure this out.

Why would I not want to parallel a panel?

Regarding the batteries. The EG4 batteries are rack mounted 6 per rack x2 racks 48V 30KW per rack. The racks have a buss bar in them. The racks are wired to a home made inclosed inverter distribution buss bar using 4/0 welding cable then #2 to 150 amp fuse to each inverter. The racks are not grounded and maybe they need to be. I have seen a few others on here that have had the problem described above.
 
After more research and checking inverter distance from aray, correction it is only 130 ft. #8wire. Also looking at inverter specifications it says mppt range is 130v to 430v. I'm not familiar with this limitation and assume you want to stay under that 430v. What happens if over that limit for a short time?

Operating Voltage is different to Voltage Open Circuit.
Look at your panels specifications but im sure you would be within the range. It could come as limitation for max Watt input but again with upto 20amps (2P) you wont face any problems.
Educate yourself with a short video on how MPPT works if you want to understand better.
 
After more research and checking inverter distance from aray, correction it is only 130 ft. #8wire. Also looking at inverter specifications it says mppt range is 130v to 430v. I'm not familiar with this limitation and assume you want to stay under that 430v. What happens if over that limit for a short time?

Operating Voltage is different to Voltage Open Circuit.
Look at your panels specifications but im sure you would be within the range. It could come as limitation for max Watt input but again with upto 20amps (2P) you wont face any problems.
Educate yourself with a short video on how MPPT works if you want to understand
 
I'm not sure if max VOC would ever be seen, calculating it with 9/s Aptos 49.9VOC and -29c coefficient at 20 degrees comes to 407.9V which would work just fine (they say to use lowest expected temp when calculating, I dont understand why as voltage goes up with higher temp)

Anyone know what's the correct way to figure this to maximize output safely? I'm still trying to figure this out.

Why would I not want to parallel a panel?

Im not too sure i understand what you say "then parallel one panel, so 3x9s one aray would have 4th panel paralleled."

Anyway if you wanted to use all panels you could do:
9s1p (1% loss with your existing cable)
9s1p (1% loss with your existing cable)
5s2p (use 10awg for 3% loss or 8awg for 2%)

If your distance was 300-320 feet like you previously mentioned - it would have required a much thicker cable for the 2p.
 
Okay I think I have this worked out. My statement of PV voltage goes up with temp was incorrect, it goes down. Knowing that helps with configuration. VOC is no load VMP is loaded which is when mppt will be maximizing, 9s vmp is well bellow the 430V max mppt spec.

So I have 28 panels total. 3x9s =27 leaving one panel that will be paralled to on of 3 arrays. The wire is 8 gage.
9s @ 49.9 = 449.10 VOC, 369.00 VMP
So arrays are 9s, 9s, 9s1p

I think that should be fine, don't you?
 
At 430v VMP, the VOC might be too high.
VOC is a hard limit. If you go over it, it's time to replace equipment.
 
Okay I think I have this worked out. My statement of PV voltage goes up with temp was incorrect, it goes down. Knowing that helps with configuration. VOC is no load VMP is loaded which is when mppt will be maximizing, 9s vmp is well bellow the 430V max mppt spec.

So I have 28 panels total. 3x9s =27 leaving one panel that will be paralled to on of 3 arrays. The wire is 8 gage.
9s @ 49.9 = 449.10 VOC, 369.00 VMP
So arrays are 9s, 9s, 9s1p

I think that should be fine, don't you?

Now i understand our miss communication..
From what i know 9s = 9s1p are the same thing. Total 9 panels.
From i gather you believe its 10 panels?
 
9s
At 430v VMP, the VOC might be too high.
VOC is a hard limit. If you go over it, it's time to replace equipment.
The 430V number is spf5000es inverter max mppt voltage. I'm assuming you use panel VMP spec to see if you are in range. The 9 panels VMP equal 369V well under the 430V spec. VOC equal 449.10 V still under 450V max VOC spec.

Should be okay don't you think?
 
9s

The 430V number is spf5000es inverter max mppt voltage. I'm assuming you use panel VMP spec to see if you are in range. The 9 panels VMP equal 369V well under the 430V spec. VOC equal 449.10 V still under 450V max VOC spec.

Should be okay don't you think?
No, that's right at the limit.
Without any headroom.
The first time the panels are under 77f or 25c , you will ruin your SCC's.
 
You can still do:
8s1p
8s1p
6s2p upgraded cable.

Its probably the only way you can use all of them..
 
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