Issue
After upgrading the firmware on a CM2000 series power meter, the meter activates the "Current Unbalance Worst" alarm.
Product Line
CM2000 Series Power Meter
Environment
Power Meter Alarms
Cause
The Current Unbalance monitoring was only available for 4-wire systems before firmware version 17.000. As of firmware version 17.000, Current Unbalance monitoring was added for 3-Wire systems.
When the firmware on a CM2000 series meter that is monitoring a three wire system is upgraded from a version previous to 17.000, the alarm appears because the meter is setting the worst current unbalance for the first time.
Resolution
Wait for the monitoring to take into account the normal fluctuations of the current. Once the worst setting is set below the normal fluctuations the system will stop alarming until a new worst case unbalance occurs.