Need some PV hookup advice

randyb509

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Dec 28, 2021
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6
PV hookup advice pls
PV specs are
220watts ....ISC 5.65A ....VOC 52.3...IPmax 5.17A......VPmax 42.7V ....max system volt 600 ..
GROWatt 24v 3000w
Max voc 145 ..
I have 6 of those solar panels the voc gets to high for the growatt max voc I was told to wire my PV in series parallel that will give me 880watts and the voc 104.6 2 panels in each string to total 4 panels..am I missing something? The watts will be low I have 4 trojan batteries 150AH each I want to wire 4 of those in series parallel...any advice would be very appreciated pls
 

randyb509

New Member
Joined
Dec 28, 2021
Messages
6
PV hookup advice pls
PV specs are
220watts ....ISC 5.65A ....VOC 52.3...IPmax 5.17A......VPmax 42.7V ....max system volt 600 ..
GROWatt 24v 3000w
Max voc 145 ..
I have 6 of those solar panels the voc gets to high for the growatt max voc I was told to wire my PV in series parallel that will give me 880watts and the voc 104.6 2 panels in each string to total 4 panels..am I missing something? The watts will be low I have 4 trojan batteries 150AH each I want to wire 4 of those in series parallel...any advice would be very appreciated pls
Can the max voc on the growatt be a little higher ? Or is the max voc145 it?
 

Rednecktek

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6 of those panels will be a 2s/3p setup as to not fry the controller in the Growatt. You'll need fuses for each string and some sort of combiner but that's not a huge deal and it looks like you've already got that planned.

You can use all 6 panels, it's good for 1440w and your panels can only provide 1320 at peak perfect conditions.

You'll want a 150a fuse on each of those battery banks, the little 60a breaker will pop every time you try to put more than about 1400 watts of load on there. Go for a 150a-175a breaker for your disconnect there.

Your inline fuses for the panels are waay over spec, use 10a fuses in there. You could put a 30a breaker as a disconnect between your fused panel strings and the AIO if you want a handy disconnect and a little more peace of mind.

Remember that those batteries are only good to a 50% discharge, so your battery banks as wired are good for 24v @ 150Ah or 3600Wh.

Other than the few small things it looks like you've got a solid plan there. :)
 

OffGridInTheCity

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>randyb509 said:
>Can the max voc on the growatt be a little higher ? Or is the max voc145 it?
You don't want to exceed the max voltage 'at all' as this can damage the internal equipment. You can typically risk over-wattage (higher amps) a bit as the unit can just shunt this like it does as you reach a full charge on the battery... but over-voltage is a no no per what I've consistently read.
 

randyb509

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Dec 28, 2021
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6 of those panels will be a 2s/3p setup as to not fry the controller in the Growatt. You'll need fuses for each string and some sort of combiner but that's not a huge deal and it looks like you've already got that planned.

You can use all 6 panels, it's good for 1440w and your panels can only provide 1320 at peak perfect conditions.

You'll want a 150a fuse on each of those battery banks, the little 60a breaker will pop every time you try to put more than about 1400 watts of load on there. Go for a 150a-175a breaker for your disconnect there.

Your inline fuses for the panels are waay over spec, use 10a fuses in there. You could put a 30a breaker as a disconnect between your fused panel strings and the AIO if you want a handy disconnect and a little more peace of mind.

Remember that those batteries are only good to a 50% discharge, so your battery banks as wired are good for 24v @ 150Ah or 3600Wh.

Other than the few small things it looks like you've got a solid plan there. :)
Ty so much I get so confused sometimes with all the numbers lol it gets a little overwhelming but you expand perfectly for me to understand . And I will get the parts u recommended for sure so I will add the other 2 panels into my PV array to run 3 on each string wired In series parallel to equal all 6 panels...should I get a combiner box ? Or those mc4 branch connectors? Ty again
 

Rednecktek

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On a boat usually.
I will add the other 2 panels into my PV array to run 3 on each string wired In series parallel to equal all 6 panels
Close, you'll need to have 3 strings of 2 panels each. If you connect 3 strings together you'll be over voltage which leads to smoke/fire/angry wife.

Since you're doing inline fuses on each string you could very easily just use the MC4 combiners. If you didn't have those in-lines I'd recommend a Simple combiner box to bring it all together, fuse each string, and provide a disconnect all at once.
 

BMcL

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Sep 5, 2021
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Ty so much I get so confused sometimes with all the numbers lol it gets a little overwhelming but you expand perfectly for me to understand . And I will get the parts u recommended for sure so I will add the other 2 panels into my PV array to run 3 on each string wired In series parallel to equal all 6 panels...should I get a combiner box ? Or those mc4 branch connectors? Ty again
I would make 3 separate runs of two panels in series to 3 ea 8 amp breakers.

You can get nice combiner boxes from Midnite Solar.
Use one breaker for each pair of panels. Your short circuit current is 5.65 amps X 1.25= 7.06 amps
So use a MNEPV8 breaker (8 amp breaker) https://www.ebay.com/itm/253264517548?hash=item3af7bdd9ac:g:hU4AAOSw4nhZ77bK

I would get a combiner box that gives you some room to add panels. The MNPV6 is nice (it comes bare, no breakers)

You can call Midnite Solar to make sure I'm telling you the correct thing ! LOL
 
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randyb509

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Dec 28, 2021
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Again ty for letting me pick ur bran I drew up this PV array let me know if I'm on the right direction pls ..also I will get the inline fuses on each pos branch of the battery bank ..I plan to upgrade to lithium someday but for now I'm in a situation that I have to get a good basic setup going for off grid living and this is basically what I have for equipment now I will also look into a combiner box I already have one in my Amazon cart lol
 

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Rednecktek

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That 175a breaker from the panels is massively overkill. You've got less than 30a total coming in, you could save yourself a few bucks and go with a 30a or 40a breaker since it's really more of a service disconnect than anything else.

The only place a heavy duty breaker/fuse set you need is from the batteries (150a fuse on each bank) and from your batteries to the AIO (as a service disconnect).

If you want to save a few bucks don't worry about the combiner box. Those inline fuses are doing the same job. Save the money for more or better batteries in the future.
 

randyb509

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Dec 28, 2021
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That 175a breaker from the panels is massively overkill. You've got less than 30a total coming in, you could save yourself a few bucks and go with a 30a or 40a breaker since it's really more of a service disconnect than anything else.

The only place a heavy duty breaker/fuse set you need is from the batteries (150a fuse on each bank) and from your batteries to the AIO (as a service disconnect).

If you want to save a few bucks don't worry about the combiner box. Those inline fuses are doing the same job. Save the money for more or better batteries in the future.
Perfect ok I'll get the inline branch mc4 instead of the box and get the fuses in the proper place ty
 
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