UPS trouble

[JoeyDaRench]

Hello,

I have a Zircon Galaxy UPS, 750-900VA. I use it for my Imac 27 inch. It is about 4 months old and has been working fine. Each time the AC compressor kicked in, it would beep and the power stayed steady, no trouble. Power goes out and the computer stays on. All good. Until last night.

The AC clicked and my computer went dead. The UPS indicated it was still on AC power. I restarted the computer with no trouble. Then, I unplugged the power to the UPS and again, the computer went dead. I assumed the battery was just junk. I took it apart today and the battery was showing over 12 volts so I plugged in a blender to the UPS, and it worked fine. I put my Imac back on it, and it won't turn on unless the power is on to the UPS. I checked the Imac and it's maximum draw on startup (and running) is .8 amps. It appears that the UPS will run things and is working, but it won't run my computer if the power is out. I know it used to work as the power has gone out. Any suggestions? I had a question about it when I first bought it and called their hotline. The English was so poor that I just couldn't communicate with them. And my wife just doesn't understand this at all and therefor, can't translate. I don't believe this is a problem with my computer, but with the UPS.

Thanks for any help.

[Crossy]

Can you measure the output voltage of the UPS when it's running something like a 60Watt desk lamp (with mains on and off)?

The symptom of it going straight off when the mains fails is normally the battery (as you correctly asserted) but there is evidently something more fundamental going on here.

EDIT A REALLY daft question, but you are plugging the computer into one of the battery backed outlets on the UPS aren't you? It wouldn't be the first time someone has been using the 'printer' output which just has surge suppression and goes off with the mains.

[JoeyDaRench]

Thanks for the reply Crossy. And yes, I'm using the backup output plugs, not the surge only one.

I will do some more testing and let you know the results.

Thanks for the help.

Joe

[JoeyDaRench]

Well, I don't have an answer but this is a weird one. i was going to disconnect it and do the testing that Crossy suggested so I decided to unplug it one more time with my computer on. It worked correctly. Then I shut down the computer and restarted it. No trouble. All of the sudden, it seems to be okay. I had fiddled with it for quite a while before testing it with a blender and no matter what, it wouldn’t work with my computer. Who knows. It must have had a brain fart. Not sure why this happened and I hope it doesn't again. I do appreciate the help though.

On a side note, does anyone know if it’s okay to replace the existing battery with an external car type battery to give longer power when the mains are off?

[Crossy]

On a side note, does anyone know if it’s okay to replace the existing battery with an external car type battery to give longer power when the mains are off?

The issues you will see using external batteries are:-

1. The beast overheating as it's only designed to run for the period that the internal battery can manage, add a fan.
2. The internal charger taking a very long time to charge the car battery, you'll need to add an external charger. But don't use a regular battery charger, use a decent switching power supply set to 13.5V or so to avoid damaging the UPS.

[JoeyDaRench]

Thanks very much for all the help Crossy. I probably won't do the car battery as I'm sure that the 15 minutes or so I'll get when the power is out should be good enough. But the information is good to know.

On a side note, it did it one more time. I came in and my computer had re-booted which tells me the power went out (at least coming from the UPS). I had forgotten about this and I'll be it's the trouble.

The power outlet in this room has had over 5 volts between the ground and neutral pins. When I say "has", that's because it does change. I was having trouble with another power supply (note a UPS) a while back

and found this. But I also found that when the power supply was having trouble, the ground was at 5+ volts. When it was working okay, the ground was around 1.5 to 1.8. I'm guessing that this trouble

is coming back as it does seem to be intermittent. Since I wasn't checking it when the UPS was having trouble, I can't say for sure.

As this is a rental house, and we're supposed to move in a little over a month, I'm not going to worry about it. And I know the landlord won't do anything. They won't fix the leaky roof.

We're just careful around the electric stuff.

Thanks again.

[IMHO]

Sounds to me like you just had a discharged battery.. The only give a few minutes runtime, but take several hours to recharge.

[JoeyDaRench]

IMHO, you could very well be correct. I just don't know. When I tested the battery, it was charged, but that was quite a while after I had the trouble.

But the trouble did happen again, as the computer had re-booted but I know we didn't have any power failures more than a second or so.

Who knows. Right now it's working. Hopefully that will continue.

Thanks for the help.