Automatic Transfer Switch: Under voltage violation

Anonymous user · ‎2021-06-28

We just installed an APC Automatic Transfer Switch Model# AP7723 (Firmware 2.0.3) and we're receiving an error that both power sources are under voltage. We've double checked the power source, amps, etc and everything should check out. We also have 2 units both having the same issue where it won't fail over and displaying the same error message.

Error message from event log below - Automatic Transfer Switch: Under voltage violation on Source B

Any help/information would be appreciated. Thanks!

BillP · ‎2021-06-28

These are used worldwide and come preset for 230V. In the US, typically 208V is used and this setting needs to be changed.

In the web UI, check under Unit ->Configuration->Frequency/voltage and check the Line VRMS setting. I presume your voltage input is likely 208V as I noted? If so, change Line VRMS to 208V and press apply. If the alarms do not clear momentarily, then you may also need to reset the ATS controller under the Control option (which take a look here FYI -> http://www.apc.com/support/index?page=content&country=US〈=en&id=FA156352 if you end up having to do that.) This resets the ATS processor which I've had to do once or twice for it to clear the error.

See Answer In Context

BillP · ‎2021-06-28

These are used worldwide and come preset for 230V. In the US, typically 208V is used and this setting needs to be changed.

In the web UI, check under Unit ->Configuration->Frequency/voltage and check the Line VRMS setting. I presume your voltage input is likely 208V as I noted? If so, change Line VRMS to 208V and press apply. If the alarms do not clear momentarily, then you may also need to reset the ATS controller under the Control option (which take a look here FYI -> http://www.apc.com/support/index?page=content&country=US〈=en&id=FA156352 if you end up having to do that.) This resets the ATS processor which I've had to do once or twice for it to clear the error.