Can a 480Y/277V rated EMA SPD be used on a 120/208V system?
Issue:
Is it possible to use a 480Y/277V rated EMA SPD on a 120/208V system?
Product Line:
TVSS/ SPD
Environment:
Application
Cause:
Verification
Resolution:
No, the clamping voltage of the EMA SPD would be too high to be effective. Using a SPD designed for 480Y/277V on a 208Y/120V system would not allow it to provide adequate protection. A 208/120V SPD would start conducting at 150V from L-G and L-N, whereas a 480/277V SPD would start conducting at 320V from L-G and L-N. Additionally, placing a 480/277V SPD into a 208/120V system would cause issues with the diagnostics due to insufficient voltage for the diagnostic circuit.
Is it possible to use a 480Y/277V rated EMA SPD on a 120/208V system?
Product Line:
TVSS/ SPD
Environment:
Application
Cause:
Verification
Resolution:
No, the clamping voltage of the EMA SPD would be too high to be effective. Using a SPD designed for 480Y/277V on a 208Y/120V system would not allow it to provide adequate protection. A 208/120V SPD would start conducting at 150V from L-G and L-N, whereas a 480/277V SPD would start conducting at 320V from L-G and L-N. Additionally, placing a 480/277V SPD into a 208/120V system would cause issues with the diagnostics due to insufficient voltage for the diagnostic circuit.
Released for: Schneider Electric USA
