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Hi,
(I've used this post on another forum, reusing here)
I've been furiously reading through posts (here and elsewhere) this last month hoping to find a silver bullet. But now I need to ask for help
We just bought a house in San Jose. Came with grid tied solar installed - but I've since learned - not producing anything. It's a 16yr old system. NEM 2 for a few more years.
Apparently it was originally two 13 panel strings connected to two inverters. Sometime later it was changed to 2x12 strings in parallel to a single inverter. The strings are connected at a roof junction. I do not know if there are diodes. Install company is out of business. Previous owner says it sometimes acted up, but hitting the inverter with a mallet helped. (I did try this against my better judgement)
Panels are LG265S1C-A3. Inverter is Sunny Boy SB6000TL-US.
System produces 0w-50w under clear midday sky. Display voltage is 345v. When I disconnect the inverter, voltage across the panels is over 400v. In June this year I generated 2kwh total. No shading. The inverter has no error codes. The green light is green (nominal working) in the mornings. Generally flashing green (standby I think) by midday.
I tried climbing a ladder and hosing the panels down. I noticed that the power jumped up to 1000w briefly, and then slowly came back down to 20w or nothing.
I had a solar repair company tell me there is a voltage leak to ground somewhere. Could be issue on the panels or the inverter (their words). They guess the inverter and quoted me $8500 to replace ($1000 for gas and credit card fees) and another $3500 to rewire the panels. I told them to take a hike.
Taking them at their word (their guess!). I think I can source my own inverter and self install. I would also separate the two strings and bring each down to the inverter.
But! I'm second guessing myself and I need advice before I throw money at the problem.
1) Do I need to worry about positively grounded panels with a modern inverter? How do I determine if my panels are positively grounded?
When measure red to ground using a cheap multimeter, I see tens of volts, slowly decreasing. When I measure black to ground, it reads millivolts instantly. These are with solar disconnected from inverter.
2) Could this be an issue with the junction box on the roof and imbalanced strings?
3) Is the inverter the most likely issue (despite no fault codes), or should I probe the panels for a short? I considered disconnecting each string in turn to see if that improves performance
5) how do my make sure the 16 year old panels aren't just toast and I would be throwing money away? Is the voltage enough proof of life?
Thanks in advance of help.
(I've used this post on another forum, reusing here)
I've been furiously reading through posts (here and elsewhere) this last month hoping to find a silver bullet. But now I need to ask for help
We just bought a house in San Jose. Came with grid tied solar installed - but I've since learned - not producing anything. It's a 16yr old system. NEM 2 for a few more years.
Apparently it was originally two 13 panel strings connected to two inverters. Sometime later it was changed to 2x12 strings in parallel to a single inverter. The strings are connected at a roof junction. I do not know if there are diodes. Install company is out of business. Previous owner says it sometimes acted up, but hitting the inverter with a mallet helped. (I did try this against my better judgement)
Panels are LG265S1C-A3. Inverter is Sunny Boy SB6000TL-US.
System produces 0w-50w under clear midday sky. Display voltage is 345v. When I disconnect the inverter, voltage across the panels is over 400v. In June this year I generated 2kwh total. No shading. The inverter has no error codes. The green light is green (nominal working) in the mornings. Generally flashing green (standby I think) by midday.
I tried climbing a ladder and hosing the panels down. I noticed that the power jumped up to 1000w briefly, and then slowly came back down to 20w or nothing.
I had a solar repair company tell me there is a voltage leak to ground somewhere. Could be issue on the panels or the inverter (their words). They guess the inverter and quoted me $8500 to replace ($1000 for gas and credit card fees) and another $3500 to rewire the panels. I told them to take a hike.
Taking them at their word (their guess!). I think I can source my own inverter and self install. I would also separate the two strings and bring each down to the inverter.
But! I'm second guessing myself and I need advice before I throw money at the problem.
1) Do I need to worry about positively grounded panels with a modern inverter? How do I determine if my panels are positively grounded?
When measure red to ground using a cheap multimeter, I see tens of volts, slowly decreasing. When I measure black to ground, it reads millivolts instantly. These are with solar disconnected from inverter.
2) Could this be an issue with the junction box on the roof and imbalanced strings?
3) Is the inverter the most likely issue (despite no fault codes), or should I probe the panels for a short? I considered disconnecting each string in turn to see if that improves performance
5) how do my make sure the 16 year old panels aren't just toast and I would be throwing money away? Is the voltage enough proof of life?
Thanks in advance of help.
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