Not reaching Absorb or Float stage -- all of a sudden

[dalyxxdj]

Thanks, Sunking, for the info. Getting smarter every day. I think I am set for the 57.6 volts you mentioned, so if everything were working as they had been, I should have been getting to Absorb then Float, which is what was happening until just recently. One last question -- on a really nice full sunny day like today, the watts coming in from the panel could reach as much as 1700 or more. I didn't notice at the time, but I assume that would have been in Absorb stage. Now the best I've seen is maybe 800 watts coming in with full sun in the middle of the day. Does the fact that I'm not getting out of Bulk stage have anything to do with the watts coming in? I hope I don't also have a panel problem!

Dan

[Mike90250]

Thanks, Sunking, for the info. Getting smarter every day. I think I am set for the 57.6 volts you mentioned, so if everything were working as they had been, I should have been getting to Absorb then Float, which is what was happening until just recently. One last question -- on a really nice full sunny day like today, the watts coming in from the panel could reach as much as 1700 or more. I didn't notice at the time, but I assume that would have been in Absorb stage. Now the best I've seen is maybe 800 watts coming in with full sun in the middle of the day. Does the fact that I'm not getting out of Bulk stage have anything to do with the watts coming in? I hope I don't also have a panel problem!

Dan

1700w v 800w bad news if you have good sunshine.
Well, do you have a combiner box ? Can you check the breakers ? Sometimes, for unknown reasons, the carlington DC breakers in mine, one of the breakers sometimes pops, not always the same one. Or try a clamp-on meter at each string, or try switching off one string at a time and see which one has no effect. ( do NOT pull fuses on a sunlit panel, or you will be arc welding ! )

[dalyxxdj]

Let me ask about my concern about the watts coming in another way: if it is a breaker, or something going on with the panels, is that at all a possible reason why I'm not getting to the Absorb stage? I got there the other day when I ran my generator? My installer possibly thought that maybe there was a wire loose somewhere, but I dismissed it since that seemed unlikely.

[paulcheung]

Or the batteries are near full on absorb mode. What is the voltage on the battery bank at that time?

[dalyxxdj]

The voltage when I could get it to Absorb on the generator was 57.6, I think, or maybe 57.8. Seemed good. As soon as the generator went off, it went very quickly (15 minutes or so) back down to 51, then 50, then 49.

[Willy T]

The voltage when I could get it to Absorb on the generator was 57.6, I think, or maybe 57.8. Seemed good. As soon as the generator went off, it went very quickly (15 minutes or so) back down to 51, then 50, then 49.

You have to post the SG level, until you do it'll just be more guesses.

[Sunking]

The voltage when I could get it to Absorb on the generator was 57.6, I think, or maybe 57.8. Seemed good. As soon as the generator went off, it went very quickly (15 minutes or so) back down to 51, then 50, then 49.

That is what a tired battery does. Having said that the battery could have died prematurely from a panel problem. Impossible to say without some test data.

Try this on your next bright clear day around noon hours. Turn on everything you can and observe what the controller reading are most notable power input from panels. What you are doing is forcing the controller to generate maximum power from the panels, but the controller has to be in Bulk mode.

[Sunking]

Now the best I've seen is maybe 800 watts coming in with full sun in the middle of the day. Does the fact that I'm not getting out of Bulk stage have anything to do with the watts coming in? I hope I don't also have a panel problem!

Dan the only time the panels are generating full power is in the Bulk mode. Anytime a charge controller is in Bulk mode is demanding full power 100% of the time. In other words of Scottie; I'm givin' all she's got Captain.


As stated earlier Bulk Mode is Constant Current which takes all the power the panel can possible generate which means full power. Absorb and Float are Constant Voltage which can be as little as 0 Watts and up to Full power and every thing in between. Think of Adsorb and Float as a battery, if there is no load or open circuit there is no current thus no power. Connect a load and only the load current flows. How much is determined what the load is demanding by it resistance.

[dalyxxdj]

Try this on your next bright clear day around noon hours. Turn on everything you can and observe what the controller reading are most notable power input from panels. What you are doing is forcing the controller to generate maximum power from the panels, but the controller has to be in Bulk mode.

Hydrometer readings won't be coming until next week when I get to town.

In the meantime, I did your test today. Here is what I found.

Pre-test: Typical sunny day in Colorado -- literally not a cloud in the sky. Controller was in Bulk mode, batteries were at about 55V, wattage coming in from panels according to the controller was about 800, AC load was about 200 watts.

During-test: Batteries dropped to about 47.5V, wattage coming in from panels according to controller didn't budge off of 800, AC load was 3200 watts. I did the test for about 5 minutes, and nothing changed with the wattage coming in.

Post-test: Returned AC load to about 200 watts, controller stayed in Bulk mode, wattage is at 800 watts coming in, and the batteries got back up to 55V.

It appears that the only thing that changed is that the batteries dropped, of course, because I had a heavy load going.

[Sunking]

You have a panel problem and battery. Do i assume correctly you have two parallel strings of panels?

Sounds like you have one sting not working.

[dalyxxdj]

Yes I have two parallel strings of 3 each. I can't see any obvious loose connections on the strings of the panels, and the junction box where everything is hooked up before the wires come in the house look OK as well. As I had mentioned, my installer thought maybe it was a loose wire either in the controller or possibly the combiner or even inverter. The battery connections all look tight and fine. Can't imagine a loose wire, but ...?

BTW, the wattage did get up to about 900 an hour later, but still that isn't enough, and, yes, at those numbers it does appear that I've only got half my panels working properly.

[Living Large]

Yes I have two parallel strings of 3 each. I can't see any obvious loose connections on the strings of the panels, and the junction box where everything is hooked up before the wires come in the house look OK as well. As I had mentioned, my installer thought maybe it was a loose wire either in the controller or possibly the combiner or even inverter. The battery connections all look tight and fine. Can't imagine a loose wire, but ...?

BTW, the wattage did get up to about 900 an hour later, but still that isn't enough, and, yes, at those numbers it does appear that I've only got half my panels working properly.

With half the power you expect, it may very well be one string. If it is, and if they are paralleled in the combiner box, the problem should be there, or back towards the panels.

Do you have fuses or breakers in the combiner box?

[dalyxxdj]

They look like fuses to me. They say: Littelfuse, POWR-SAV, 600V, 30A on them. Here's the pic. IMG_1484.JPG I can't figure out how to/or if I even should (safely) open up the cover on the panel to see what is going on behind the fuses. Or how I would test them if I was able to get it open and check them out?

[Sunking]

BTW, the wattage did get up to about 900 an hour later, but still that isn't enough, and, yes, at those numbers it does appear that I've only got half my panels working properly.

Real easy to figure out. Disconnect one string and see what happens. If nothing happens you found the bad string. You can figure out the other possibility.

If I had to guess I would say your installer used a fuse in each string, and one opened up. It is pretty easy to troubleshoot. Start with disconnecting one string and see what happens and where that leads you.

Here is the big picture. At some point one string failed cutting power in half. That lead to chronic under charging of the batteries and destroyed them. Fix the panels and replace the batteries with an appropriate sized capacity and you should be good for a few years. Learn from your mistakes, learn how to use a Hydrometer and monitor your system. Do that and you will spot a problem as soon as it appears and can take corrective action. That is what bit you in the butt. Don't let it happen again.

[Sunking]

They look like fuses to me. They say: Littelfuse, POWR-SAV, 600V, 30A on them. Here's the pic. [ATTACH=CONFIG]6534[/ATTACH] I can't figure out how to/or if I even should (safely) open up the cover on the panel to see what is going on behind the fuses. Or how I would test them if I was able to get it open and check them out?

Open them up and take a look. There is not enough voltage or current to hurt you or the system. Remove them and check with an Ohm meter. If they are glass you will be able to see the fuse link.

That is how you can disconnect one string at a time to test.