Are AFCIs required to undergo monthly testing like GFCIs?

Question: AFCI

Are AFCIs required to undergo monthly testing like GFCIs?


Similar to GFCIs, UL 1699, the Standard for Arc-Fault Circuit Interrupters does require monthly testing. This requirement is communicated in the installation instructions. The installation instructions are also standardized to reduce the likelihood of miswiring.

Information and current Listings for AFCIs can be found under the category of Arc-Fault Circuit Interrupters, Branch/Feeder Type (AVZQ) and Arc-Fault Circuit Interrupters, Outlet Branch Circuit Type (AWBZ) on the UL Certification Database

Question: GFCIs and horsepower

Do GFCI receptacles carry a horsepower rating?



GFCI receptacles do have a horsepower rating; the horsepower rating of the receptacle would correspond to the standard horsepower ratings found in the Guide Information for the category, Receptacles for Attachment Plugs and Plugs (RTRT). For a 125V, 15A receptacle the horsepower rating is ½ horsepower and for 125V, 20A receptacle the horsepower rating is 1 horsepower.

GFCIs are Listed under the category Ground-Fault Circuit Interrupters (KCXS) and are not intended to act as “ON/OFF” controls for motors or other loads, unless the buttons are specifically marked “ON”/”OFF.”

Question: Antioxidant compounds

Are antioxidant compounds required on all aluminum wire connectors?



Some UL Listed aluminum wire connectors are prefilled with the UL Listed antioxidant compounds at the factory. For the non-prefilled connectors, the antioxidant compounds should be used if recommended by the manufacturer.

However, the non-prefilled connectors meet the requirements in UL 486B, the Standard for Wire Connectors for Use with Aluminum Conductors, without the compound.

Wire Connectors for use with aluminum conductors are Listed under the category Wire Connectors and Soldering Lugs (ZMVV). Antioxidant compounds are Listed under the category Conductor Termination Compound (DVYW). Compounds under this category have been evaluated and shown not to cause adverse effects on the conductor/conductor combination.

Question: Switch rated GFCIs

Some GFCIs are “switch rated.” Are all GFCIs with a deadfront “switch rated”?



The “TEST” and “RESET” buttons on a GFCI are only intended to check the proper functioning of the GFCI. They are not intended as “ON” “OFF” controls of motors or other loads. Only GFCIs that are specifically marked “ON”/”OFF” have been “switch rated.” Products with “ON” and “OFF” markings have been additionally Listed as “Miscellaneous Motor Controllers” (NMFT).

Question: Bubble covers and GFCI

Since it is required as part of the Listing to use a bubble cover with GFCIs in wet locations, shouldn’t the NEC be revised to indicate this?


When used in wet locations, UL Listed GFCI receptacles are required to have a weatherproof (“bubble”) cover. This is specified in the “standardized” installation instructions provided with all UL Listed GFCI receptacles. These installation instructions are outlined in UL 943, the Standard for Ground Fault Circuit Interrupters.

In regard to revising the NEC, in the proposed 2002 NEC, new Article 406, Section 406.8(B)(1) will require a weatherproof cover for 15 and 20A outdoor receptacles in wet locations.

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