Ok so I ran into an issue today. The power flicked out a couple times then came back on (this has happened a few times in the past month, and according to the guy at the power company it was a breaker tripping out and resetting due to a fried critter).. When it finally stayed on, I could hear the constant buzzer from the UPS, and it was showing overload. I shut it off and turned it back on, things started up normally. It was only showing 280w load (it's a CyberPower OR1500LCDRM-2U, 1500VA/900W, so nowhere near the rated limit). I pulled the plug and it went into overload again. On utility power, it starts up and runs just fine with all loads. With no loads connected it will cold start off the batteries just fine, but plugging literally ANYTHING into it while on battery shuts it down. Even a wall wart.
My first thought was the batteries are getting some years on them and maybe starting to lose capacity, but I just did a runtime test a couple months ago and it went for about 65 minutes before the low battery warning with the same loads connected (the server which pulls about 200W shuts down at 90%, in order to maximize time for the network gear, but avoid shutdowns for blips and short outages since it has to be manually turned back on).
Then I thought I might've yanked a battery cable loose from the pack (4x batteries, 2x 24v series in parallel) when I moved it recently, but again it's not complaining about low battery, it's tripping into overload.
So now I'm thinking this quick set of on/off cycles might've surged it. I opened it up and don't see anything burnt up, no fuses blown, but it's been about 25 years since electronics class. Since I am able to cold start it with no load, I did that and let it run just to see what happens, if nothing else it'll recalibrate the runtime meter, and it has actually been running for over 5 hours now before the low battery warning just kicked on. It's still at 10% so it'll probably go at least another half hour or so before it shuts off.
I'm assuming there is something going on with the inverter circuit since it passes power on utility. Any ideas where to start? I have a multimeter and an oscilloscope if someone is familiar with the inner workings of these things and can offer guidance... I really don't want to have to toss it, because I don't want to have to spend hundreds of dollars on a new one.
My first thought was the batteries are getting some years on them and maybe starting to lose capacity, but I just did a runtime test a couple months ago and it went for about 65 minutes before the low battery warning with the same loads connected (the server which pulls about 200W shuts down at 90%, in order to maximize time for the network gear, but avoid shutdowns for blips and short outages since it has to be manually turned back on).
Then I thought I might've yanked a battery cable loose from the pack (4x batteries, 2x 24v series in parallel) when I moved it recently, but again it's not complaining about low battery, it's tripping into overload.
So now I'm thinking this quick set of on/off cycles might've surged it. I opened it up and don't see anything burnt up, no fuses blown, but it's been about 25 years since electronics class. Since I am able to cold start it with no load, I did that and let it run just to see what happens, if nothing else it'll recalibrate the runtime meter, and it has actually been running for over 5 hours now before the low battery warning just kicked on. It's still at 10% so it'll probably go at least another half hour or so before it shuts off.
I'm assuming there is something going on with the inverter circuit since it passes power on utility. Any ideas where to start? I have a multimeter and an oscilloscope if someone is familiar with the inner workings of these things and can offer guidance... I really don't want to have to toss it, because I don't want to have to spend hundreds of dollars on a new one.