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Incorrect Power Factor readings in Virtual devices in System Manager Software v 4.0

Goals and Symptoms

Incorrect Power Factor (PF) readings can occur in Virtual devices within SMS (System Manager Software) v 4.0 when associated meters are configured with an alternate VAR sign convention. This article will explain why it occurs and how to resolve the issue.

Causes and Fixes

All PowerLogic meters except for the Series 2000 Circuit Monitor (CM2000) are shipped using the IEEE/IEC VAR sign convention. Meters shipped previous to March 2000 were shipped using the Alternate (CM1/CM2/CM2000/PM600) VAR sign convention. SMS only calculates Power Factor correctly when the IEEE/IEC VAR sign convention is used. Therefore, every meter included in a Virtual device must be configured with the IEEE/IEC VAR sign convention.

The VAR sign convention can be changed through the display of the Series 3000, 4000 Circuit Monitor and the Series 800 Power Meter. To change the VAR sign convention on the CM2000 or PM600 (Series 600 Power Meter) refer to the device reference manual. All devices can be configure over the communications link by reading and writing to the command interface. Refer to the command interface in the device reference manual.

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