a few dumb questions

[Anonymous user]

I admit I'm in over my head. I inherited a cluster system that has a SMART-UPS VT. According to people about, it
has "never" worked. Although I don't quite believe it (I can see in the logs that it has more than once switched over
to battery power), something is amiss since some of the machines on it rebooted when it did switch over. It's not
clear that anyone in the past performed the power calcuations.

I appear to have the 10kVA 208V version with one battery pack installed.

My initial questions:

The Vin reads 116.8, 115.9 and 117.3 and fluctuates wildly, whereas the Vout is a steady 119.8. Is this normal?

There is a 30 amp (I think) curcuit that goes to the Smart-UPS and then to a breaker box (30 amp primary breaker). Two
20 amp (?) breakers run to two sets of 4 plugs. PDUs are next and the computers themselves are plugged into the
PDUs. However, even though there are more than a few computers plugged into the PDUs, the load on the UPS
still reads 0.00. Is that normal?

Thanks very much for any help.

[upsguy_apc · Accepted solution]

If your input voltages swing around wildly you may be missing the input neutral to ground bond in the upstream transformer.

Pull the front cover off of the UPS and on the left side there should be a small handle that has a label that says maintenance bypass. Is the handle pointing up and down or left to right?

Normal conditon with the computer load protected is left to right, the up and down position is maintenance bypass. I think your load currents go to 0 in maintenance bypass....

If you have any questions about the status of the UPS call into APC tech support and they can help you out.

800-800-4272 follow the prompts to 3 phase tech support. Have the UPS serial number handy. Its on a small white sticker on the bottom of the UPS.