solar problems/need guidance

[tim a]

this is our first post. we purchased the house with a system installed but not functioning correctly. no contract. I believe it has 46 200 watt panels from sunpower, 3 spr3200 inverters. no monitoring system yet. active in 2005.
two inverters seem to start up normal then after 5 minutes or so restart then go active again( green light on panel). this happens all day. the ac/dc voltages seem good. the ac side 120v on both legs, dc side has approx. 300 v, but I am getting little to no amps on either. from 0.0 to 2.5 amps. the third inverter keeps blowing the gfi fuse on the dc side. i'm guessing there is a short or something on those panels. my thinking is to remove, check, repair any wiring problem. could the one set of panels be effecting the other 2? need advice. we have alittle solar experience with a motor home. we added 4 310w panels, 2 Morningstar mppt60 controllers, 1450ah batteries and a Tri-Star monitor. this made off-grid camping a much better experience. any help with an attack plan would be greatly needed and appreciated.

[J.P.M.]

If system quick checks or help here doesn't solve it, I'd attack the problem by a call to vendor that installed the system. If you do not know the vendor, a little snooping around the inverters, etc., may reveal it. And/Or, if you are in CA, the CSI database may have the system. A little snooping there will quickly reveal who the vendor was.

Welcome to the neighborhood.

[sensij]

Sunpower frequently markets their superior warranty, and systems can only be installed by authorized agents, so you might have some luck if you contact Sunpower directly. Whether the original installer is still around or not, they might be able to direct you towards someone that can help.

At 12 years old, inverter failure is high on the list of possibilities. Replacing them could be tough... that style of inverter is not compliant to current electrical code, and the panels themselves probably perform best when wired with "positive ground", which was a Sunpower oddity that was eventually designed out of their panels.

To get 300 V strings, you probably have something around 7 panels per string. With 46 panels, I'd guess something like two 7 panel strings on one inverter, and two 8 panel strings on each of the other two inverters. Those strings need to be combined somewhere... if there is just a single set of leads coming into the inverter, then the combining probably occurs in a junction box on the roof. That is the first place I'd look for a short to ground. Even if the connections in the j-box look good, you could try running with just one string, and then the other, to see which string has the fault. If the fault persists on both strings, it probably means there is something wrong in the inverter.

[tim a]

jpm , the company is out of business now. and I live in nj. and thanks for the welcome!

[tim a]

sensij, that's good info there, thanks. to be on the safe side I was going to put cardboard over the panels after I shut everything done. is that over kill? a bonus of checking out the panels is I will know how they were wired together. there are 3 pairs and a ground , one pair going to each inverter.yes there is a junction box on the roof under one of the panels. if I have to replace the inverter(s) then ill have to changed those panels to normal negative ground?( just reverse wiring to the new inverter?)

[sensij]

sensij, that's good info there, thanks. to be on the safe side I was going to put cardboard over the panels after I shut everything done. is that over kill? a bonus of checking out the panels is I will know how they were wired together. if I have to replace the inverter(s) then ill have to changed those panels to normal negative ground?( just reverse wiring to the new inverter?)

No, what I'm saying is that the panels probably perform best when the DC+ is tied to ground. It is hard to find an inverter today that will do that. Definitely verify what you have, but if you can find a Sunpower installer with experience supporting these older systems, they will probably have some idea of a good path forward, or access to equipment that could be used for replacement. Most inverters sold today are transformerless, and if you want to follow code, it isn't as simple as just dropping one of those into your existing installation.

Cardboard over the top of them is probably overkill, but until you isolate the ground fault, it wouldn't be a bad idea on at least the strings going to that inverter.

[bcroe]

sensij, that's good info there, thanks. to be on the safe side I was going to put cardboard over the panels after I shut everything done. is that over kill? a bonus of checking out the panels is I will know how they were wired together. there are 3 pairs and a ground , one pair going to each inverter.yes there is a junction box on the roof under one of the panels. if I have to replace the inverter(s) then ill have to changed those panels to normal negative ground?( just reverse wiring to the new inverter?)

You WON'T BE SAFE by putting cardboard over your panels. They will still generate about the same
voltage, at much reduced current but PLENTY to be dangerous. There may be multiple problems;
I'd start by understanding the wiring arrangement and fixing the ground fault.

Your strings come together somewhere, trace exactly how that is done. Having found leads for each
string, disconnect them AT NIGHT. When the sun comes up, check for solid voltage between ground
and either lead of one of the strings; that is the one with a ground fault. I actually use a string of 75W
bulbs to make sure its a low impedance fault, not static. The voltage from ground, compared to the
entire string leads, will give a hint at the location of the fault. Once the GFI fault is fixed, move on
to other issues. Bruce Roe

[tim a]

I understand, I will keep updates as they arrived. thanks to all. last question, should I expect amps from the strings? if I remember if each panel puts out 5 amps the string should only be 5 amps, but the volts will multiply by the number of panels in the string? night idea is great! and a lot cooler

[J.P.M.]

jpm , the company is out of business now. and I live in nj. and thanks for the welcome!

Hey, I took a shot.

Seriously though, I'd then read Sensij's post and consider his suggestions/comments, including thje part about the inverter taking a dump. I'd add that I've found dealing with Sunpower to be not much, if any better, and sometimes worse than dealing with other outfits. I get more dead air on the other end than with other vendors/mfgs.

I'd still call a local vendor. If it is the inverter, depending on how the panels/B.O.S may/may not be compatible with a new inverter, will be an interesting tell on the alleged superiority of the S.P. warranty and how it translates as either a way for S.P. to duck, or as a way for S.P. to show it's veracity in the area of warranty superiority.

Good luck,

[tim a]

i'm not sure if I am under warranty being the second owner. the house was vacant not sure if old owner purchased the system or defaulted on a contract. all I know is the title was clear.

[cebury]

Seriously call Sunpower first. Vendors brag how if they go out of business, the sunpower network will always be around to help. Id start there before I'd touch anything. You have a lot of unsure info, might as well get some confirmations. They may even help you despite if last owner defaulted. Corporate may have been paid, even if the local installer didn't. Not trying to beat ya over the head, but its been suggested here already and sometimes it all works out for the price of a phone call or maybe a service call. If they drop a big dollar estimate on you, at least youll be more informed about your system as you ask them questions.

[tim a]

Seriously call Sunpower first. Vendors brag how if they go out of business, the sunpower network will always be around to help. Id start there before I'd touch anything. You have a lot of unsure info, might as well get some confirmations. They may even help you despite if last owner defaulted. Corporate may have been paid, even if the local installer didn't. Not trying to beat ya over the head, but its been suggested here already and sometimes it all works out for the price of a phone call or maybe a service call. If they drop a big dollar estimate on you, at least youll be more informed about your system as you ask them questions.

true enough.

[J.P.M.]

i'm not sure if I am under warranty being the second owner. the house was vacant not sure if old owner purchased the system or defaulted on a contract. all I know is the title was clear.

I'm not either, but my warranty, in effect when I bought my S.P. system, (08/2013) under condition 2 (b.) :

" Warranty claims may only be made by, or on behalf of (i) the original owner or customer, as named in the certificate of guarantee or invoice, as applicable, and (ii) any subsequent title holder of the PV modules upon satisfactory proof of succession or transfer from the original end customer as named in the certificate of guarantee or invoice, as applicable."

It will be interesting to see if the expiration of the 10 yr. warranty on the inverter, as well as any subsequent code requirements making a replacement inverter perhaps incompatible with the existing system will affect how S.P. may look at how such things may impact the suitability under warranty for the modules or the rest of the system, if at all.

Above all, safety first ! I'd stay clear of fooling with the system at all unless you are a licensed electrician knowledgeable in PV system installation and maintenance.


Add to that: Under my warranty from S.P, sec. 3: The Limited Warranty does not apply to any of the following : (a)...."repair or modifications by someone other than an approved service technician of Sunpower"... Call Sunpower and get their response in writing before you act on your own. If you call Larry with a ladder, anything (s)he does without their consent/knowledge may well void any warranty, whatever it may be.

[tim a]

they said inverters not covered and are looking into the panels. i'm not holding my breathe

[tim a]

they said if a panel is bad they will warranty it, and said they can change the system over from a positive ground system. they gave me a list of 5 companies.