PC Shut Down Despite Being Connected to UPS?

[Gessler555]

I have a 14700K/1080Ti rig I've recently put together. It's got a Corsair HX1000i PSU connected to a APC Smart-UPS SUA1500I-IND pure sinewave UPS.

 

I was running a OCCT Power Test (that pushes CPU & GPU simultaneously) and I manually shut down the switch on the wall socket that the UPS was connected to in order to a simulate a power loss and see if the UPS can successfully transfer to battery but the PC just shut off.

 

The UPS's circuit breaker did not trip.

 

What's surprising is that I've had this same setup go into battery operation during this stress test at least once before (that I triggered manually) and since the shut down event, I've repeated the same conditions twice over (same test) and it successfully transferred to battery every time. Including during idle & gaming scenarios as well.

 

I've had it go on battery during actual power loss events, and it never had a problem then either.

 

The UPS is rated for 1500va/980W and my system's power draw was around 650W with a peak of around 700 during the OCCT test.

 

Was it just a fluke?

[freeagent]

What did your 12v, 5v, and 3.3v look like before it crashed?

[Gessler555]

27 minutes ago, freeagent said:

What did your 12v, 5v, and 3.3v look like before it crashed?

 

I wasn't monitoring that unfortunately. Out of curiosity, why do you ask?

 

The only variable I can think of between the one time when it just shut off compared to all the other instances is that the battery charge level of the UPS was significantly lower as it had just come off of operating for about 4-5 minutes on battery under similar loads (~650W).

 

Could the lower charge level have led to a higher than usual transfer time maybe?

[freeagent]

Could be, I do not have experience with a UPS, so I cannot say. 

[Gessler555]

1 minute ago, freeagent said:

Could be, I do not have experience with a UPS, so I cannot say. 

 

May I know why you asked about the PSU voltages?

[freeagent]

4 minutes ago, Gessler555 said:

 

May I know why you asked about the PSU voltages?

If you start to see your 12v rail down near 11.2v, 5v near 4.5v, or 3.3 down to around 2.8v, then you have PSU issues. And you should replace it post haste

[Gessler555]

15 minutes ago, freeagent said:

If you start to see your 12v rail down near 11.2v, 5v near 4.5v, or 3.3 down to around 2.8v, then you have PSU issues. And you should replace it post haste

 

My voltages are 12.1, 5.1 and 3.3v

 

There is no change in voltage when the UPS goes on battery.

 

I've never had any problems with this PSU.