Surge arresters should be selected by rated voltage, MCOV, nominal discharge current, housing material, creepage distance, pollution level, line type and mounting accessories.
Buyer checklist
Confirm system voltage and grounding method.
Check MCOV and insulation coordination.
Confirm polymer or porcelain housing.
Confirm IEC 60099-4 and test report requirement.
Specify brackets, counters, disconnectors or cable leads when needed.