[SOLVED] UPS losing power when mains power comes back again

[rounakr94]

Hello,
Noticed a weird issue with my brand new APC Back UPS 1100va.
When power goes off the PC goes into backup mode without any issue, but once mains power returns the UPS cuts off power for the outlets for a split second and my PC restarts.
Why is this happening?
Note: This happens only when PC is in high load like gaming.
UPS model is apc bx1100c

 

[jasonf2]

Looking over the specs on your ups it is an offline line interactive with a stated switchover time of 10-12ms. If the switchover time is greater than 12ms (stated maximum) your UPS is bad. If the switchover time is less than 12ms your power supply just isn't good enough to handle the switchover time. With the question being answered let me elaborate a little more though. In the UPS world there are generally speaking three levels of UPS. Every company has marketing names for the levels, but I will list them like this: Offline (Cheapest), Offline Line Interactive, Full Online (Most Expensive). Offline is simply a battery backup that engages when a full mains fail is detected. It takes a little bit for it to turn on after the mains fail so the switchover time is stated with the unit. Offline Line interactive is basically the same as an offline, but it will have the ability to tweak some of the incoming mains without using the battery. So while it can adjust something like a minor sag or swell it still has a small delay when a full mains failure happens while it engages the battery. The third type, a full online, takes all of the incoming mains power and reconstructs it entirely. In the event of a mains failure the battery is online and available to the dc bus of the UPS all of the time so there is zero switchover time because it can supplement the incoming power, not just replace it. If you are dealing with constant dirty power a full online will cost an arm and a leg, but it is a viable fix for most power quality issues because of its reconstructive nature. I know everyone has one (sarcasm), but the only real way to test this is with an oscilloscope. I would probably throw the UPS away and get a new one. The other thing is that you are running a marginally sized bronze level power supply. Corsair is a good brand but I never suggest going any lower than a 750 watt power supply in the first place and no lower than 80+ gold (I prefer titanium). All manufactures bronze lines are their value lines and you get what you pay for. In this case your power supply's dc bus capacitors may be just a little too weak to hold the switchover time under full load.

 

[rounakr94]

Looking over the specs on your ups it is an offline line interactive with a stated switchover time of 10-12ms. If the switchover time is greater than 12ms (stated maximum) your UPS is bad. If the switchover time is less than 12ms your power supply just isn't good enough to handle the switchover time. With the question being answered let me elaborate a little more though. In the UPS world there are generally speaking three levels of UPS. Every company has marketing names for the levels, but I will list them like this: Offline (Cheapest), Offline Line Interactive, Full Online (Most Expensive). Offline is simply a battery backup that engages when a full mains fail is detected. It takes a little bit for it to turn on after the mains fail so the switchover time is stated with the unit. Offline Line interactive is basically the same as an offline, but it will have the ability to tweak some of the incoming mains without using the battery. So while it can adjust something like a minor sag or swell it still has a small delay when a full mains failure happens while it engages the battery. The third type, a full online, takes all of the incoming mains power and reconstructs it entirely. In the event of a mains failure the battery is online and available to the dc bus of the UPS all of the time so there is zero switchover time because it can supplement the incoming power, not just replace it. If you are dealing with constant dirty power a full online will cost an arm and a leg, but it is a viable fix for most power quality issues because of its reconstructive nature. I know everyone has one (sarcasm), but the only real way to test this is with an oscilloscope. I would probably throw the UPS away and get a new one. The other thing is that you are running a marginally sized bronze level power supply. Corsair is a good brand but I never suggest going any lower than a 750 watt power supply in the first place and no lower than 80+ gold (I prefer titanium). All manufactures bronze lines are their value lines and you get what you pay for. In this case your power supply's dc bus capacitors may be just a little too weak to hold the switchover time under full load.

Okay then out of Antec EAG650W (Rebranded Seasonic Focus Gold) and XPG Core Reactor (CWT Custom High end) which one will you suggest?

 

[jasonf2]

Either should be fine. If purchasing a new power supply right now though I would lean towards a 750 watt due to the power demands of the new Nvidia GPUs. It gives you some upgrade room down the line.

 

[rounakr94]

Looking over the specs on your ups it is an offline line interactive with a stated switchover time of 10-12ms. If the switchover time is greater than 12ms (stated maximum) your UPS is bad. If the switchover time is less than 12ms your power supply just isn't good enough to handle the switchover time. With the question being answered let me elaborate a little more though. In the UPS world there are generally speaking three levels of UPS. Every company has marketing names for the levels, but I will list them like this: Offline (Cheapest), Offline Line Interactive, Full Online (Most Expensive). Offline is simply a battery backup that engages when a full mains fail is detected. It takes a little bit for it to turn on after the mains fail so the switchover time is stated with the unit. Offline Line interactive is basically the same as an offline, but it will have the ability to tweak some of the incoming mains without using the battery. So while it can adjust something like a minor sag or swell it still has a small delay when a full mains failure happens while it engages the battery. The third type, a full online, takes all of the incoming mains power and reconstructs it entirely. In the event of a mains failure the battery is online and available to the dc bus of the UPS all of the time so there is zero switchover time because it can supplement the incoming power, not just replace it. If you are dealing with constant dirty power a full online will cost an arm and a leg, but it is a viable fix for most power quality issues because of its reconstructive nature. I know everyone has one (sarcasm), but the only real way to test this is with an oscilloscope. I would probably throw the UPS away and get a new one. The other thing is that you are running a marginally sized bronze level power supply. Corsair is a good brand but I never suggest going any lower than a 750 watt power supply in the first place and no lower than 80+ gold (I prefer titanium). All manufactures bronze lines are their value lines and you get what you pay for. In this case your power supply's dc bus capacitors may be just a little too weak to hold the switchover time under full load.

Got the Antec eag pro 750. Seems to be working fine

 

[jasonf2]

Got the Antec eag pro 750. Seems to be working fine

Glad to hear it!