Voltage but no amperage

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Hello Everyone. I've been having a problem with voltage but no amperage on one of my solar panels at my ice house in Minnesota. I got 2 used (tested) Kyocera KC120 panels off ebay. I have called the company I purchased the panels from, and they're stumped at the moment...having to call around to find a possible fix. I thought I'd toss it out to you guys to see if you have any solutions.

Kyocera KC120-1
VOC 21.5
ISO 7.45
VMP 16.9
IMP 7.1

Today is a high of -2 degrees today, so setup 2 500w halogen work lights to energize the panel inside my house for testing. I understand that 16v is low and that bulbs arent the same as the sun, but it was the only way I could get exact and repeatable numbers for testing without freezing my fingers. From previous tests, I know that when the panel is outside in good sun its putting out 20-21 volts (10v on both sides with very similar voltage on both sides)

Here is what I'm pulling with my multimeter (see picture for terminal connections) (1 is negative side, 4 is positive)
Terminal 1 to 4 16.5v .01a
Terminal 1 to 3 9.5 5.1a
Terminal 2 to 4 7.5 0.0a

When the panel is in the full sun, both sides are very similar voltage. The 2 volt difference I am currently showing is an issue with my temporary testing setup inside the house.

I've tested each individual diode with my diode setting on my multimeter, each showing .450 or so. After putting them back in the panel I get .417 from terminal 3 to 4 and .395 from terminal 1 to 2 (again, using the diode setting on my DMM). The interesting thing is when I run from 4 to 3 I get an open loop because of the blocking diodes BUT from 2 to 1, it shows 1.441 on the DMM

Knowing that all 3 blocking diodes are working and functioning properly when removed, that tells me that something is loose or shorted out somewhere else in the panel?

Front of the panel looks clean, no massively corroded ribbons, no obvious burn/melted areas. Anyone have ideas of what might be causing this type of problem?

Panel Box.JPG

[sensij]

I think you may be too focused on voltage. Under what conditions do you expect current but are not seeing it? Have you measured Isc yet?

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I don't know why, but the photo is 90 degrees off on the post. If you click on it, it shows up vertically and is easier to see.

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Its a fish house, so it will move depending on where I want to fish. I know something is wrong with this panel because I have 2 identical panels, setup in the same location, facing the same angle etc. One puts out good voltage (20-21v) and good amperage 5-6.5 amps depending on the day, the other is this one with no amp output. From what little I know about panels, shouldn't I be geting 10v 5a on each of the 2 halves? (I picked 5amps just as a theoretical number...obviously everything depends on sun angle, clouds, etc). I have not measure ISC yet..I'll do that in a bit and get back to you.

[Sunking]

There is only two things you can measure.

Voc which can be done in even house lighting.

Isc is the only other thing you can measure and it takes bright full sun at solar noon with the panels facing directly into the sun.

If the panel fails Voc, stop because Isc has no chance of passing.

Reference this.

[jflorey2]

Its a fish house, so it will move depending on where I want to fish. I know something is wrong with this panel because I have 2 identical panels, setup in the same location, facing the same angle etc. One puts out good voltage (20-21v) and good amperage 5-6.5 amps depending on the day, the other is this one with no amp output.

How are you measuring the 5-6.5 amps?

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How are you measuring the 5-6.5 amps?

2 ways.
First is my meter panel...analog gauge showing current from my controller to the battery bank. This way won't always be accurate due to the state of charge on my batteries.

Second is run through my multimeter (bypassing the controller).

[Sunking]

2 ways.
First is my meter panel...analog gauge showing current from my controller to the battery bank. This way won't always be accurate due to the state of charge on my batteries.

Second is run through my multimeter (bypassing the controller).

Read my first response and follow the Link. You are measuring current incorrectly. You test the panels outside in the sun not connected to anything. Your results are garbage.

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Read my first response and follow the Link. You are measuring current incorrectly. You test the panels outside in the sun not connected to anything. Your results are garbage.

I understand, I know how to test voc and isc. I said I would get back to you with those numbers once we get a sunny day here in Mn.

I never tested ISC on either panels, I know i checked VOC, but I cant remember exactly what they were. Somewhere in the 20-21 range. The reason I don't have all the numbers under optimal circumstances is that I hvae one panel (the one working) on my fish house, 2 hours away and the non working panel is here at my house, where its been either cloudy or bitterly cold. I'll get true ISC and VOC numbers on the bad panel as soon as the weather improves. Thanks

[littleharbor]

Check the mfg. date code on your panels. Kyocera had problems with switching to a lead free solder in 1999. Any panels dated between 1/1999 and 12/2002 are within that run of panels. Kyocera will replace any panels within these date codes, no questions asked, well almost. I personally have had 36, 50 and 48 KC-120's replaced by Kyocera. The ONLY place to test these panels for voc and isc is the + and - marked terminals.

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Check the mfg. date code on your panels. Kyocera had problems with switching to a lead free solder in 1999. Any panels dated between 1/1999 and 12/2002 are within that run of panels. Kyocera will replace any panels within these date codes, no questions asked, well almost. I personally have had 36, 50 and 48 KC-120's replaced by Kyocera. The ONLY place to test these panels for voc and isc is the + and - marked terminals.

I will check the manufacture date tonight. All current info I've given in the thread so far has been when hooked to a load (dead battery)

Checked VOC and ISC in less than optimal sunlight conditions this morning. Got 18.5v and 3.8a which has me confused. Why I get current (all be it low due to poor light conditions) on ISC test but nothing when hooked up to a load (battery around 11v). User error is possible but I (and an electrician) can't get any current when hooked to a load

[Sunking]

Bypass the controller and connect the panels directly to the batteries.If you see them start charging you have a dead controller. Real simple to troubleshoot any electrician could do in less than 2 minutes.

Another easy way, takes more time. is disconnect the panels from the controller. Check Voltage Open Circuit from panels. Then short the panels out and measure current. If you have voltage and current the panels are good. Reconnect panels to controller and if the batteries are not charging, guess what? Controller is dead

The other possibility is your batteries are shot. If you see something like 14.5 volts with the controller connected to panels and batteries with no charge current during the day, then batteries are toast and open circuit.

Personally from what you described so far sounds like your Controller has let the magic smoke out. Just disconnect the panels from controller and go directly to the batteries. I bet you find the controller is bad. If so fire that Electrician because he is as dumb as a rock and could not trouble shoot a burnt out light bulb.

[Switchback]

Bypass the controller and connect the panels directly to the batteries.If you see them start charging you have a dead controller. Real simple to troubleshoot any electrician could do in less than 2 minutes.

Another easy way, takes more time. is disconnect the panels from the controller. Check Voltage Open Circuit from panels. Then short the panels out and measure current. If you have voltage and current the panels are good. Reconnect panels to controller and if the batteries are not charging, guess what? Controller is dead

The other possibility is your batteries are shot. If you see something like 14.5 volts with the controller connected to panels and batteries with no charge current during the day, then batteries are toast and open circuit.

Personally from what you described so far sounds like your Controller has let the magic smoke out. Just disconnect the panels from controller and go directly to the batteries. I bet you find the controller is bad. If so fire that Electrician because he is as dumb as a rock and could not trouble shoot a burnt out light bulb.

Sunking, we were on the same train of thought. When the bad panel issue arrose I isolated my gauge panel, then I isolated the controller and still had the same problem. Furthermore, I currently have one panel connected to the controller and it is charging properly (at least it was when I left). I'll run a good VOC and ISC test whenever the sun decides to shine again in Minnesota and start from there.

Shorted cell on my bank also crossed my mind 2 weeks ago as well. Not knowing how to diagnose a shorted cell, I switched batteries. Good cell put out 4-6amps at the same voltage as the battery (mid 12v). Switched batteries again and same result...charging rate was the same, voltage was different but the backup battery was a different state of charge.

If I removed the diodes, should there be continuity between the 2 negative terminals? Likewise on the 2 positive terminals? Only reason I ask is because with the diodes installed I was getting continuity on the negative side in both directions (first post in the thread). I switched the positive and negative diodes and got the same result.

Thanks for your help everyone.

[sensij]

If I removed the diodes, should there be continuity between the 2 negative terminals? Likewise on the 2 positive terminals? Only reason I ask is because with the diodes installed I was getting continuity on the negative side in both directions (first post in the thread). I switched the positive and negative diodes and got the same result.

Those are not intended to be two negatives and two positives. The cells in the panel are in series, with just one + and one - for the entire series. The bypass diodes (not blocking diodes) allow the current to route past a shaded section of cells.

Have you looked at the j-box documentation?

A conventional 36 cell circuit would look like this. You can see that + in that sketch would correspond to your terminal 4, and - to your terminal 1. Your terminals 2 and 3 should show continuity. The bypass diode are not shown in the drawing, but you can see how they would enable 18 cell to be bypassed if those cells were shaded and the diodes become forward biased.

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Those are not intended to be two negatives and two positives. The cells in the panel are in series, with just one + and one - for the entire series. The bypass diodes (not blocking diodes) allow the current to route past a shaded section of cells.

Have you looked at the http://www.kyocerasolar.com/assets/001/5155.pdf"]j-box documentation[/URL]?

A conventional 36 cell circuit would look http://www.pveducation.org/pvcdrom/modules/module-circuit-design"]like this[/URL]. You can see that + in that sketch would correspond to your terminal 4, and - to your terminal 1. Your terminals 2 and 3 should show continuity. The bypass diode are not shown in the drawing, but you can see how they would enable 18 cell to be bypassed if those cells were shaded and the diodes become forward biased.

The second link you sent is great. (I have looked over the j box/panel info numerous times). I knew the blocking diodes prevented back voltage to shaded parts but not what the 2 middle terminals did in relation to the overall panel. Thanks for the info