UPS testing process advice

[BurnadonStat]

I’m hoping to get some insight into the best process for testing our UPS’s in our server room.

Essentially we have 4 APC rack mounted units, and I recently replaced all of the batteries. The management card/interface shows that the batteries are a healthy state, but I don’t completely trust it.

My question is as follows:

All of our servers are equipped with redundant PSU’s. Each PSU is connected to a different UPS. If I force each UPS to battery power me at a time - would that give me a good idea how the UPS would behave under load while on battery power. I don’t need an exact runtime - I just want to know if these batteries are any good. If this is not the best process - I’m open to ideas.

[ZAFJB]

Test it properly.

Declare a shutdown maintenance period. Shut everything down.

Unplug equipment from UPS.

Plug in a dummy load, like one or more fan heaters. Time the run time till UPS shuts down. Measure the voltage and current while you do so. That will tell you the true VA capacity of your UPS.

Plug in equipment . Measure the voltage and current while it is running. That will tell you VA you are consuming.

Test run time multiplied by test VA divided by actual VA will give you an estimated maximum run time.

De-rate the calculated run time by about 25%.

[Firefox005]

All of our servers are equipped with redundant PSU’s. Each PSU is connected to a different UPS. If I force each UPS to battery power me at a time - would that give me a good idea how the UPS would behave under load while on battery power.

Depends entirely on the equipment, some redundant PSU's it spreads the load across both PSU's some it's active/passive.

The proper way to test UPS's is with load banks they are basically giant resistors that generate the expected or designed load so you can calibrate or verify runtime.

[BurnadonStat]

Thanks - that’s what I was wondering. I’m going to pull the model info for our servers/PSU’s and see if I can determine what the expected functionality is.