Product Line:
Surge Protective Devices (SPDs)

Environment:
Application

Cause:
Clarification

Resolution:

No, the Metal Oxide Varistors (MOVs) integrated within the Surge Protective Device (SPD) will experience immediate failure when subjected to sustained overvoltage conditions. The SPD in question is designed with a Maximum Continuous Operating Voltage (MCOV) rating of 320V phase-to-ground. In a Delta-configured electrical system, however, the phase-to-ground voltage reaches 480V, which substantially exceeds the MCOV specification of a 480Y/277V-rated SPD.

This persistent overvoltage condition imposes continuous electrical stress on the MOVs, driving them beyond their thermal and electrical design limits. As a result, the MOVs undergo accelerated degradation, which may culminate in either premature end-of-life or catastrophic failure, thereby compromising the protective functionality of the SPD.

Released for: Schneider Electric Canada