Tracking motor capability of MOVs to maintain design operability

The purpose of this paper is to develop a methodology to measure the motor capability of AC motors used in motor operated valves (MOVs) under a degraded voltage condition. The methodology is based on the measurement of the motor at the motor control center that can readily be performed during surveillance testing or in an outage. Field verification of the methodology is also provided to assure reliability. This approach will help resolve verifying the AC MOV's design basis capability at torque switch or control switch trip settings. The methodology can be effectively used at the motor control center and predict reliably the left torque capability of the motor to resolve the response to NRC GL 95-05 (periodic verification testing).