Triplight UPS Issue - Page 1
Forum section: electronics / general

author: larrybl
author_rank: Regular Contributor
timestamp: April 20, 2021, 02:17:16 am
content: I was given a 1440W Triplight UPS. Battery was dead so I ordered a new one and installed. Everything was working fine, then we had some T-Storms coming in so I put my computer on it and was good for about 6 hours then it just shut off (Main power never went off). I put the computer back on the power strip, and moved the UPS to the bench. I ran it with no-load and it shut off after about 16 hours. I then plugged a shop light in and the UPS shut off again after about 16 hours. I performed the self tests described in the manual and it performed as described.I am not against tearing into this as I only have $19.99 tied up with the new battery. Inverter works, Switching from mains to battery and back again works. I am guessing an issue with the power on circuit. Could not find a diagram, so this could prove to be difficult with my skill level.Suggestions?

author: james_s
author_rank: Super Contributor
timestamp: April 20, 2021, 02:34:45 am
content: You mean it's shutting off while it's still plugged into the wall? Usually the only thing wrong with old UPS's is the batteries go dead, but even with a dead battery they should keep supplying the load while plugged in. I would check the electrolytic capacitors, especially if it has any of the surface mount type, those are notorious for failing. You might have a bad capacitor in the power supply that powers the logic.

author: larrybl
author_rank: Regular Contributor
timestamp: April 20, 2021, 12:02:25 pm
content: Yes, it just shuts off while plugged in. I powered it back up yesterday, and this morning it is still working. Seems the up-time is getting longer after each un-intended shut down.

author: tom66
author_rank: Super Contributor
timestamp: April 20, 2021, 12:25:30 pm
content: Cold solder joints would be worth looking at too.

author: jmelson
author_rank: Super Contributor
timestamp: April 20, 2021, 04:40:32 pm
content: Quote from: larrybl on April 20, 2021, 12:02:25 pmOhhh, that sounds like a symptom of deteriorated electrolytic caps!Jon

author: larrybl
author_rank: Regular Contributor
timestamp: April 20, 2021, 10:02:15 pm
content: Yea, It's still on after the power on yesterday, almost 24 hours this time. If it goes off again I may open it up and see if any are bulging or leaking.

author: james_s
author_rank: Super Contributor
timestamp: April 20, 2021, 10:51:38 pm
content: That certainly suggests that they are in bad shape. IMHO it is prudent to replace them now if in doubt, a UPS is absolutely useless if it results in cutting power to the protected equipment during a time that the incoming power is not interrupted, rather than maintaining power to the equipment during an outage. They may temporarily recover to some degree but that is not a fix, they will fail sooner or later.

author: larrybl
author_rank: Regular Contributor
timestamp: April 20, 2021, 11:40:19 pm
content: I can't confirm, but I think this is a 2011 model. Still working, The top of the case is warm, not hot.

author: larrybl
author_rank: Regular Contributor
timestamp: April 22, 2021, 10:09:10 pm
content: It died again after estimated 30 hours. I could use one of the old school 110V electric clocks that stops when the power goes off to get an accurate run time.

author: james_s
author_rank: Super Contributor
timestamp: April 22, 2021, 11:31:29 pm
content: Or you could just fix it, because it's obviously broken and will never be trustworthy until you determine the cause of the problem and correct it.

author: larrybl
author_rank: Regular Contributor
timestamp: April 23, 2021, 02:50:03 am
content: I'll open it up tomorrow, but 99% sure I won't find the problem.

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2021, 05:15:00 am
content: Just replace the small electrolytic capcitors, there's probably a switchmode power supply IC and there will be some capacitors associated with that. You can also look around for cracked solder joints, particularly on the relays.

author: larrybl
author_rank: Regular Contributor
timestamp: April 23, 2021, 03:29:57 pm
content: Not seeing anything out of sorts. I can buy a new 400va ups for less than $50.00 US, which most likely would be less than trying to locate the issue and fix this.

author: james_s
author_rank: Super Contributor
timestamp: April 23, 2021, 06:08:45 pm
content: I see several capacitors that I would suspect, but a visual inspection is completely useless in most cases, they have to get *really* bad before showing any visible signs of problems. You need a ESR meter or a can of freeze spray/air duster can be useful. If you don't feel like trying to troubleshoot it though just replace it, they are cheap and easy to find.