Heard a loud pop *APC BKUP XS 1500

[Mad_Professor]

So I don't know what happen exactly, It's an APC Backup XS 1500.

Sorry this is going to be long but I think details are the best way to explain a situation.

I was sitting here at my desktop in my bedroom around 3pm today browsing youtube when I heard a loud pop. My sister was sitting infront of the workstation where the backup was when it happened. She is hearing impaired and still heard it, but was unable to tell me the general direction or location the "pop" came from. I figured it came from outside because of my window was open. As I tried to load another video, I lost my connection to the internet.

I walk out to the workstation where my server and the modem are located and everything was off. I thought "WTH? the breaker must of tripped." I go back to the panel nothing tripped. Walk back out noticed one of the computers my dad was working on was plugged in on the same circuit and was the last receptacle of the run and had not been interrupted. Also the HP laserjet 6MP was also plugged in on the same plug that battery backup was on which was at the beginning of the run and it had not gone through it's warm up/power on cycle.

*Confused* I turned on the server and walk back to the panel and push the test button on the breaker *combo AFCI* which tripped. I walk back to the server it was off along with everything else. Looked at the battery backup it says 100% charge but acts as if the battery was dead.

This whole time there was no smell or smoke, and my dad has very sensitive nose especially to electrical/electronic burning/burnt smell.

Something is wrong here. I unplugged the battery backup and dragged it out, check the internal breaker it had not been tripped. Plugged it into a power strip then plug in a 75w lamp to the Battery backup, switched off the power strip and the backup switched over to battery. It went from 710 minutes run time to 0 in 1 minute, then the lamp ran for another 30 seconds as the backup warn me of a low charge then the lamp went out followed by the battery backup.

This is weird because 3 weeks ago I had issues with the POCO. A fuse kept blowing at the pole and my battery backup worked fine ran 20 minutes with a 300w load then.

I took apart the battery backup and inspected the board and didn't find anything burnt or blown. Noticed it had capxon caps all over and one cap had a slight bulge on top. Put it back together. Tested batteries *two 12v in series* it said 24v, a fully charged battery would be at 27v if I remember correctly.

So now I'm left wondering what was the loud pop and why is my battery backup now not working.

Could it be the batteries? They are about 2 years old now, replaced in 2010. Was that the loud pop? The battery pack seems to be intact, no swelling or physical anomaly.

Could it be the massive transformer in the backup that went *pop* and is that causing the rapid discharge now?

I'm curious never had anything like this happen before.

Any ideas, or what I should be looking for? I checked all devices to the backup they seem to be working fine. I'm confused.

http://www.apc.com/resource/include/...D&tab=features

[dmill89]

Re: Heard a loud pop *APC BKUP XS 1500

I'm not sure about that exact model but I used to have an XS900. It had a 40mm sleeve bearing fan that seized up which caused the switching transistors to overheat and blow out with a loud pop, then It would just continuously beep and do nothing, batteries were fully charged but it wouldn't run on battery or AC. The XS 1500 you have is a newer unit so there may be some design differences. If you have a fan definitely check it. APC tends to cheap out on its consumer grade units so things like low quality caps and fans are very common, the last couple I opened up had either jamicon or CapXon (many only 85C)caps and if they had a fan it was a sleeve bearing.

[Mad_Professor]

Re: Heard a loud pop *APC BKUP XS 1500

I took the whole backup to the batteries plus and we tried one of their batteries with a dremel drill load and it held it's run time for 2 minutes. SO it was bad batteries.

Now to figure out what that loud pop was.

[RJARRRPCGP]

Re: Heard a loud pop *APC BKUP XS 1500

So I don't know what happen exactly, It's an APC Backup XS 1500.

Sorry this is going to be long but I think details are the best way to explain a situation.

I was sitting here at my desktop in my bedroom around 3pm today browsing youtube when I heard a loud pop. My sister was sitting infront of the workstation where the backup was when it happened. She is hearing impaired and still heard it, but was unable to tell me the general direction or location the "pop" came from. I figured it came from outside because of my window was open. As I tried to load another video, I lost my connection to the internet.

I walk out to the workstation where my server and the modem are located and everything was off. I thought "WTH? the breaker must of tripped." I go back to the panel nothing tripped. Walk back out noticed one of the computers my dad was working on was plugged in on the same circuit and was the last receptacle of the run and had not been interrupted. Also the HP laserjet 6MP was also plugged in on the same plug that battery backup was on which was at the beginning of the run and it had not gone through it's warm up/power on cycle.

*Confused* I turned on the server and walk back to the panel and push the test button on the breaker *combo AFCI* which tripped. I walk back to the server it was off along with everything else. Looked at the battery backup it says 100% charge but acts as if the battery was dead.

Sounds like a problem I had with an APC UPS all the way back in late May, 2002:

All of a sudden, my Phillips 107S CRT monitor wasn't getting power, so IIRC, I unplugged the monitor then plugged in back in.

IIRC, when I plugged it back in, there was a pop and a blue spark!

"POP!" right in my ears!

Then since that, the battery back up outlets are dead!

The plug contacts were faulty!

[kc8adu]

Re: Heard a loud pop *APC BKUP XS 1500

may have been a cell(the bad one?)venting.
they have little rubber caps retained by a cover.some pop and some squeal/whistle when they vent.
does yours stink of outgassing plastic?
i have 3 of these i set up for external batteries and they do well other than they stink.

[Mad_Professor]

Re: Heard a loud pop *APC BKUP XS 1500

Sounds like a problem I had with an APC UPS all the way back in late May, 2002:

All of a sudden, my Phillips 107S CRT monitor wasn't getting power, so IIRC, I unplugged the monitor then plugged in back in.

IIRC, when I plugged it back in, there was a pop and a blue spark!

"POP!" right in my ears!

Then since that, the battery back up outlets are dead!

The plug contacts were faulty!

I check the contacts for wear and tear they seem to be alright. Checked the receptacles at the wall, they're ok, they should be, they're brand new only several years old.

may have been a cell(the bad one?)venting.
they have little rubber caps retained by a cover.some pop and some squeal/whistle when they vent.
does yours stink of outgassing plastic?
i have 3 of these i set up for external batteries and they do well other than they stink.

No, no smell from the batteries, they are a sealed unit. Can't check them now since I replaced them with new ones today.

I don't know, whatever it was, it will rear it's ugly head eventually.

[kc8adu]

Re: Heard a loud pop *APC BKUP XS 1500

not the batteries the whole ups.its the plastic case that stinks.

[Mad_Professor]

Re: Heard a loud pop *APC BKUP XS 1500

not the batteries the whole ups.its the plastic case that stinks.

Remember when I said it would rear it's ugly head? Well... half my house has no electricity. The double pole 70 amp breaker for the subpanel went bad around 8:30 tonight. It didn't trip, still in the "on" position. One leg failed, the other still provided power. After attempting to do a full reset on the breakers it wouldn't, it felt spongy.

Called an electrician, he dropped a used 50 amp double pole breaker, turned out that one was bad too, only one leg worked. That's all he had until the morning. So now half the house is dark.

Most likely the loud pop came from there and eventually failed now.

[kc8adu]

Re: Heard a loud pop *APC BKUP XS 1500

well at least you found the problem!and found that your ups batts were done before a power problem ocurred that could cost you data.
maybe a run test every few months?

[Mad_Professor]

Re: Heard a loud pop *APC BKUP XS 1500

well at least you found the problem!and found that your ups batts were done before a power problem ocurred that could cost you data.
maybe a run test every few months?

4 weeks ago they held a charge and ran on battery for 20 minutes, two days ago they couldn't. I would have to test weekly.

Anyways electrician, different guy came with a new double pole 60 amp breaker since he wasn't legally allowed to install a 70 due to wire size. All is well, new breaker is running 50x cooler then the last one. The old one was hot when it failed, and ran warm/hot when it operated normally. At least we're ok, I had him check out the subpanel to see if there was any issues, but there wasn't much concern; even with the grounds tied to the neutral bus bar.