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Uninterrupted Power Supply (UPS) query

stealthjoe

New Member
Hello,

I have a 1KVA UPS with 4 power outlets and was having the following devices connected:

20 inches LED monitor
PC CPU (i5-2400, 16GB RAM, 4 x 120 mm fans, GTX 970, 2 HDDs)
HP All-In-One inkjet printer

Recently I connected my Creative A520 5.1 speaker system to the UPS as previously its SMPS (now got a new one in its place) got busted due to a power surge. Hence didn't want to take a chance further.

Initially (few days back), while switching on the UPS (the UPS mains are always ON), it was only then the subwoofer and speakers used to power up. Then after I switch off the UPS button after shutting down the PC, the speakers used to power OFF as well.

Today morning I noticed that after I shutdown my PC and turn OFF the UPS, the sub and speakers are still ON. It is only when I switch OFF the the UPS mains, would the speakers also switch OFF. Previously, it was not the case as the speakers were dependent on the ON-OFF cycles of the UPS power button.

I am confused on why this is happening. Is there some circuit inside the UPS which may have got messed up? Could someone please throw their insights on this?

Regards,
Joe
 

rjenkinsgb

Well-Known Member
Have you changed which devices are in which outlets?

Some UPSs have a mix of outlets, some fed from the battery backup system and some "straight through", with only surge suppression.
 

stealthjoe

New Member
Hi rjenkinsgb,

The UPS has 4 sockets (cpu, monitor, printer and speakers) and all are battery backup outlets. The thing is all the sockets now are receiving power directly (straight through) even before switching on the UPS. I am able to switch on the PC/printer as well with the UPS power button switched off. Previously it was not the case. However, my battery backup is working fine.

I am having a query. I recently connected my creative speakers to the UPS. Since connecting it, there was a pop/thump from the subwoofer every time I switched on/off the ups. This was happening a few times till I then noticed that there were no pops since the ups button now no longer controls the on/off cycle. Could the sub thumping/pops have caused some short within the ups button?

Regards,
Joe
 

rjenkinsgb

Well-Known Member
It is possible the switch - or a relay that controls - has welded and is no longer disconnecting power.
Depending on how that specific UPS works, that may mean the backup part is no longer functional, if that same relay is used to switch to the inverter section.

What happens if you turn power off at the wall while the UPS is on? It should continue to power the speakers & monitor etc.
(I'd not have the PC running when you try that, just in case..)
 

stealthjoe

New Member
It is possible the switch - or a relay that controls - has welded and is no longer disconnecting power.
Depending on how that specific UPS works, that may mean the backup part is no longer functional, if that same relay is used to switch to the inverter section.

What happens if you turn power off at the wall while the UPS is on? It should continue to power the speakers & monitor etc.
(I'd not have the PC running when you try that, just in case..)
I think it is to do with the switch. Actually it now works at times, provided I press the switch firmly while turning the UPS ON and OFF. Also my PC backup works after I turn OFF the main power to the UPS during times when the switch doesn't work.
 

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