Name your price for drawing up a simple diagram. I will pay it!!! Please! Desperate.

[Visionguild]

Hey Robby, This is great info. Again, I really appreciate you taking the time on this. I wish I could treat you and your partner to a dinner or something. Please let me know if I can.
I was out all evening and have to work all day today away from my computer so I haven't had a chance to absorb what you wrote above but it does make sense. I will be able to really look at it tomorrow and can reply in a more meaningful way. Just wanted to get on and say thanks again and that I'll be back on tomorrow with my head in the game. Hope you have a good day today and I look forward to chatting with you more. btw, my email is clay@visionguild.com if you feel like taking this off thread. No worries if not though. Talk to you soon, Cheers! Clay

Hey Robby, Clay here, from a few months ago. I'm actually finally getting around to doing my panels. Been going over all the post from earlier and saw this one. What if I used 15 of them, 3 sets of 5 in series attached in parallel? Added an image. This way my Voc would be 205. It leaves on panel off but that's ok. I can make use of it elsewhere. Thanks so much.

 

[robby]

Hey Robby, Clay here, from a few months ago. I'm actually finally getting around to doing my panels. Been going over all the post from earlier and saw this one. What if I used 15 of them, 3 sets of 5 in series attached in parallel? Added an image. This way my Voc would be 205. It leaves on panel off but that's ok. I can make use of it elsewhere. Thanks so much.

Hi Clay
There is nothing wrong with it except that you have two Inverters and each one needs some panels.
Is this a drawing for just one Inverter? I so your slightly over the maximum allowed wattage of the MPPT input.
Also you will need fuses.

 

[Visionguild]

Hi Clay
There is nothing wrong with it except that you have two Inverters and each one needs some panels.
Is this a drawing for just one Inverter? I so your slightly over the maximum allowed wattage of the MPPT input.
Also you will need fuses.

Oh yeah, duh. Geez, I'm such a noob. Ok, so yeah, your original post is accurate. I can't get anymore panels, that are an exact match to the ones that I have. I guess I can look online and find something if I need too. I'll wire them up then as you described and I guess I'll just see if they'll work. I'll do some hunting online too, just in case. Thanks Robby. I really appreciate it. I'll let you know how it goes.

 

[Visionguild]

Hi Clay
There is nothing wrong with it except that you have two Inverters and each one needs some panels.
Is this a drawing for just one Inverter? I so your slightly over the maximum allowed wattage of the MPPT input.
Also you will need fuses.

Hey Robby, Clay again. Hope you don't mind. So I included a pic of the specs in the manual. You had posted above regarding the preferred 5S2P, "I would have felt more comfortable with a 5S2P which would be 207Vdc and working Voltage of 166V with Aprox 19 Amp. That is nicely inspec with this Inverter 250V and 22Amp max capabilities." My question is about the 22Amp max you have calculated. I thought it was 80 based on a video of Will's on these and these specs. No? I was thinking of maybe doing 5S2P to one inverter and then 5S to the other inverter and leave one panel out of the loop as I have 16 total. Or if the amp max for the controller is 80, I could run the remaining 6 in parallel, but then I'm pushing the Voc all the way up to 246. Do you think that's too close to it's max? Thank you. My offer to paypal you so you can take your partner out to dinner always stands by the way.

 

[Visionguild]

Hi Clay
There is nothing wrong with it except that you have two Inverters and each one needs some panels.
Is this a drawing for just one Inverter? I so your slightly over the maximum allowed wattage of the MPPT input.
Also you will need fuses.

Just had a thought, does the solar need to be identical on each inverter? Maybe my thoughts of how to do it on my last post won't work. They would be running in split phase parallel operation.

 

[acdoctor]

Panel specs from post #1. 41.5 VOC 9.5 amps
You have 16 panels, you need 8 on each inverter. 4S2p is 4 in series with 2 strings of those parallel to one inverter. 8 panels,168 volts 19 amps input. In the future you could add more panels.

 

[Visionguild]

Panel specs from post #1. 41.5 VOC 9.5 amps
You have 16 panels, you need 8 on each inverter. 4S2p is 4 in series with 2 strings of those parallel to one inverter. 8 panels,168 volts 19 amps input. In the future you could add more panels.

Thanks so much! Ok, so another user on here, Robby, had posted this as a concern,
"The one thing I do not like and your just going to have to test and find out is if that 4S2P is going to be enough for that Inverter. According to the Manual the startup voltage from the panels needs to at least 150Vdc. Your panels are going to produce 41.49Vdc each x 4 panels is 165Vdc and a working voltage of 133V The manual says +/-10Vdc so it could be 160Vdc to activate the Inverter and a minimum working voltage of 120Vdc. That 5-15Vdc wiggle room is a little close for my comfort and I somehow think Will needed 130 working volts to get his running. "
I wasn't sure if this was something that I needed to address right away, try to get more panels or if a different configuration would work. Sounds like maybe I just need to set it up and give it a try. I really appreciate your reply. This has been a bit of a struggle knowledge wise.

 

[MisterSandals]

Sounds like maybe I just need to set it up and give it a try.

There you go!
I was going to suggest this but wasn’t sure how feasible it would be. You could try with 4S at first and if that was unsatisfactory, see if 4S2P is better.

I would watch for how high the sun needs to be to start charging. If it’s late in the morning, maybe try 5S to see if charging starts significantly earlier. Same with sun setting.

 

[Visionguild]

There you go!
I was going to suggest this but wasn’t sure how feasible it would be. You could try with 4S at first and if that was unsatisfactory, see if 4S2P is better.

I would watch for how high the sun needs to be to start charging. If it’s late in the morning, maybe try 5S to see if charging starts significantly earlier. Same with sun setting.

I was just able to get 4 more of the same panels I have so I can do 5S2P for each inverter now. Should be good to go. Thank you for your help

 

[Visionguild]

Hi Clay
There is nothing wrong with it except that you have two Inverters and each one needs some panels.
Is this a drawing for just one Inverter? I so your slightly over the maximum allowed wattage of the MPPT input.
Also you will need fuses.

Hey Robby, just a heads up. I was able to just get 4 more of those same panels so I'll be doing a 5S2P set up for each inverter. Thanks for your help with this. Should be good to go. Cheers!

 

[robby]

Hey Robby, just a heads up. I was able to just get 4 more of those same panels so I'll be doing a 5S2P set up for each inverter. Thanks for your help with this. Should be good to go. Cheers!

Your Welcome and please show us some pictures once she is up and running.

 

[Visionguild]

Your Welcome and please show us some pictures once she is up and running.

Thanks, I will. I still need to do the AC side. I'll get this part going first at least. Cheers!

 

[Visionguild]

I am going to try and keep it light on the Tech Jargon because I know you have been bombarded by it.

I am home now and just wanted to look at a few things again and something kind of stuck out at me.
You have 16 panels and I assume you were thinking of running a four in series and then parallel them with another 4 in series (4S2p) type configuration. The Unconnected/Open Circuit voltage (Voc) . from those panels is
The one thing I do not like and your just going to have to test and find out is if that 4S2P is going to be enough for that Inverter. According to the Manual the startup voltage from the panels needs to at least 150Vdc. Your panels are going to produce 41.49Vdc each x 4 panels is 165Vdc and a working voltage of 133V The manual says +/-10Vdc so it could be 160Vdc to activate the Inverter and a minimum working voltage of 120Vdc. That 5-15Vdc wiggle room is a little close for my comfort and I somehow think Will needed 130 working volts to get his running. Maybe someone with the same model inverter can chime in.

I would have felt more comfortable with a 5S2P which would be 207Vdc and working Voltage of 166V with Aprox 19 Amp. That is nicely inspec with this Inverter 250V and 22Amp max capabilities.

The 4S2P setup is nothing to worry about, but just make sure you have room to mount another panel in each series string if the Inverter will not start charging the batteries. The down side if that happens is that you would need four more panels. I think you might be okay but I just wanted you to be aware that if nothing is happening then this could be the reason. Also the MPPT tends to track better when they have more range to play with.

Hey Robby, ol visionguild here. I'm sorry to bother you. I'm finally starting to hook things up. I know, ridiculous how long it's taken me. So I was looking at the manual and it says the max amperage for the inverter is 18amps. I see you have 22Amps listed and I do have the 5S2P set up that you thought would be good. I'm just wondering where you got 22Amps? If it's really 18Amps, am I back to square one? I have all the panels set up in 5S2P and will have to uninstall them, no small job as it took me weeks to get them on the roof to rewire them. fingers crossed I'm not screwed. Thanks for your help

 

[Visionguild]

I am going to try and keep it light on the Tech Jargon because I know you have been bombarded by it.

I am home now and just wanted to look at a few things again and something kind of stuck out at me.
You have 16 panels and I assume you were thinking of running a four in series and then parallel them with another 4 in series (4S2p) type configuration. The Unconnected/Open Circuit voltage (Voc) . from those panels is
The one thing I do not like and your just going to have to test and find out is if that 4S2P is going to be enough for that Inverter. According to the Manual the startup voltage from the panels needs to at least 150Vdc. Your panels are going to produce 41.49Vdc each x 4 panels is 165Vdc and a working voltage of 133V The manual says +/-10Vdc so it could be 160Vdc to activate the Inverter and a minimum working voltage of 120Vdc. That 5-15Vdc wiggle room is a little close for my comfort and I somehow think Will needed 130 working volts to get his running. Maybe someone with the same model inverter can chime in.

I would have felt more comfortable with a 5S2P which would be 207Vdc and working Voltage of 166V with Aprox 19 Amp. That is nicely inspec with this Inverter 250V and 22Amp max capabilities.

The 4S2P setup is nothing to worry about, but just make sure you have room to mount another panel in each series string if the Inverter will not start charging the batteries. The down side if that happens is that you would need four more panels. I think you might be okay but I just wanted you to be aware that if nothing is happening then this could be the reason. Also the MPPT tends to track better when they have more range to play with.

I'll reach out to growatt and/or signature solar tomorrow too to find out if the 18Amp max is going to be an issue. Cheers!

 

[robby]

There seems to be a constant mix up on the signature solars documentation. Some Inverters will have no issue with the current being higher, so ask them. This is so long ago that I am even confuse now. I am looking at your original product link and I see 80 Amps. Something sounds off.

 

[Visionguild]

There seems to be a constant mix up on the signature solars documentation. Some Inverters will have no issue with the current being higher, so ask them. This is so long ago that I am even confuse now. I am looking at your original product link and I see 80 Amps. Something sounds off.

Thanks Robby, according to the manual, the 80Amp number is the Max PV charging current, while the max PV input current is 18Amps. I don't know what the difference is between charging and input. I'll call them tomorrow and see. Thanks for trying buddy. I know this is an old thread.

 

[Visionguild]

There seems to be a constant mix up on the signature solars documentation. Some Inverters will have no issue with the current being higher, so ask them. This is so long ago that I am even confuse now. I am looking at your original product link and I see 80 Amps. Something sounds off.

Oh, charging current is how much is going to the battery. I see, so I guess the PV input is the number I have to look at. 18Amps sure seems low. fingers crossed it can handle more than that.

 

[Hedges]

80 amps output. Into 48V that would be 3840W. Bit higher voltage, reaches the rated 4000W.

If your two 4s (or 5s) strings were oriented differently, would not hit peak current at the same time. So could be below 18A.
What is the Imp spec and the Isc spec of the panel?
Need to find out if "Max PV input current 18A" is maximum it converts to output power, or maximum short-circuit current.

Sometimes (but maybe not for all designs), short circuit current limit only matters if you hook PV panels backwards. Which can be avoided, with care and double-checking.

 

[Visionguild]

80 amps output. Into 48V that would be 3840W. Bit higher voltage, reaches the rated 4000W.

If your two 4s (or 5s) strings were oriented differently, would not hit peak current at the same time. So could be below 18A.
What is the Imp spec and the Isc spec of the panel?
Need to find out if "Max PV input current 18A" is maximum it converts to output power, or maximum short-circuit current.

Sometimes (but maybe not for all designs), short circuit current limit only matters if you hook PV panels backwards. Which can be avoided, with care and double-checking.

The imp is 9.48 A and the Isc is 10.37

 

[Hedges]

Assuming 90 degree angle between strings, 10.37 x 2 x 0.7 = 14.5A (estimate) maximum in direct sun.
Actual current occasionally goes higher due to cloud edge effects (which would be the case for an array all one orientation as well.)
With some angle between the strings, seems to me you can stay under 18A even if that is a short-circuit limit.
And of course double-check voltage and polarity before closing switch or otherwise making final connection.