Question: GFCI without 15-A NEMA configuration receptacle
A standard 20-amp rated duplex receptacle has a NEMA 20-A polarized configuration, however, some ground-fault circuit interrupter (GFCI) receptacles that carry a rating of 20 amps are provided with a 15-A NEMA configuration receptacle. Can you tell me why the GFCI is not the same?
Ground-fault circuit interrupters are Listed under the category of the same name with the category code (KCXS) located on page 170 in the 2007 UL White Book. Ground-fault circuit-interrupter receptacles are evaluated for compliance with the Standard for Safety for Ground-Fault Circuit Interrupters, UL 943. Presently, UL 943 addresses GFCI ratings in terms of their contact rating. Since the NEC permits all 15-ampere receptacles to be used on 20-A branch circuits, the contacts are required to be rated at 20 amps since they open the downstream portion of the branch circuit connected to the load terminals. The Standard requires the contact rating to be marked on the GFCI so that even if the receptacle is a 15-A configuration, it will still have a 20-amp rating. Some manufacturers mark the devices 20-A, 15-A receptacle.