Question Power Supply fails when UPS is on battery

[henry-nicolas]

Hello,

I have an issue with a server power supply which completely fails to run and power the server when the underlying ups in on battery.
This can occur when the ups run a self-test, resulting in a hard reset of the server or if the ups is on battery, then the server is flicking/buzzing and going through a power reset multiple time per second (does not look good at all).

The PSU is : AcBel 550W redundant PSU (load is about 80w)
The UPS is : APC Back UPS Pro 1500VA + external battery extension

Also weird: when the UPS go on battery, other equipements connected to this UPS stay online (router, wifi access point), so that seems to point at the PSU.
I tried swapping the PSU with another spare I had and the behavior remains the same.

Any idea what could be the cause of this? Seems crazy that the PSU can't run at all while on UPS battery ...

Regards,

 

[henry-nicolas]

Some test I´v done as well:

• behavior is the same if I connect only one of the 2 psu on the ups
• behavior is the same if I unplug/replug power cords while ups is on battery
• behavior is the same if the server is the only device connected on the ups

 

[huege23]

I know this post is old but I figure maybe this will help others I also have very little experience on forums, so if this is the wrong thing to do I'm sure I will find out.

The problem you are having is probably caused because your UPS uses a simulated sine wave or similar. If your power supply has automatic switching you need to use a UPS that has a pure sinewave.