Issue:
Surge Protective Device Specification
Product Line:
Surge Protective Devices
Environment:
Products sold in North America
Resolution:
Nominal Discharge Currents, often marked as Inominal or I(n) , indicate the amount of current to which sample SPDs have been subject during UL 1449-prescribed tests. Inominal ratings are required to designate the SPD Type, which indicates the environments in which an SPD may be installed. For example, to receive a 20kA Inominal rating, the SPD must survive fifteen 8x20 microsecond transients at 20kA as well as other safety tests.