There is no limit placed, by the listing agency, on the number of downstream receptacles.
Ground-fault Circuit Interrupters
Guide Information for Electrical Equipment for Use in Ordinary Locations
GENERAL
This category covers ground-fault circuit interrupters (GFCI) for use in accordance with ANSI/NFPA 70, "National Electrical Code" (NEC).
A GFCI is a device whose function is to interrupt the electric circuit to the load when a fault current to ground exceeds some predetermined value that is less than that required to operate the overcurrent protective device of the circuit.
A GFCI is intended to be used only in a circuit where one of the conductors is solidly grounded.
Class A GFCIs trip when the current to ground has a value in the range of 4 through 6 mA. Class A GFCIs are suitable for use in branch and feeder circuits, including swimming pool circuits. However, swimming pool circuits installed before local adoption of the 1965 NEC may include sufficient leakage current to cause a Class A GFCI to trip.
Class B GFCIs trip when the current to ground exceeds 20 mA. These devices are suitable for use with underwater swimming pool luminaires installed before the adoption of the 1965 NEC.
A GFCI of the enclosed type that has not been found suitable for use where it will be exposed to rain is so marked.
A receptacle type GFCI installed in wet locations is intended to be installed with an enclosure that is weatherproof, whether or not the attachment plug cap is inserted.
The "TEST" and "RESET" buttons on the GFCIs are only intended to check for the proper functioning of the GFCI. They are not intended to be used as "ON/OFF" controls of motors or other loads unless the buttons are specifically marked "ON" and "OFF." Products with "ON" and "OFF" markings have been additionally Listed under Motor Controllers, Mechanically-operated and Solid-state (NMFT).
Some GFCIs include receptacles, and are intended to be installed in an enclosure similar to a conventional receptacle. Receptacle type GFCIs may have been additionally found to meet appropriate requirements and are marked "hospital grade" and/or "CO/ALR." See Receptacles for Plugs and Attachment Plugs (RTRT) for further information.
REBUILT PRODUCTS
This category also covers rebuilt or refurbished portable GFCIs. These are factory rebuilt to the extent necessary to replace components such as cords, plugs or cord connectors. Rebuilt GFCIs are subject to the same requirements as new GFCIs.
ADDITIONAL INFORMATION
For additional information, see Electrical Equipment for Use in Ordinary Locations (AALZ).
REQUIREMENTS
The basic standard used to investigate products in this category is ANSI/UL 943, "Ground-Fault Circuit-Interrupters."
UL MARK
The Listing Mark of Underwriters Laboratories Inc. on the product is the only method provided by UL to identify products manufactured under its Listing and Follow-Up Service. The Listing Mark for these products includes the UL symbol (as illustrated in the Introduction of this Directory) together with the word "LISTED," a control number, and the product name "Ground-fault Circuit Interrupter."
For rebuilt products the word "Rebuilt" or "Refurbished" precedes the product name.
"Reprinted from the Online Certifications Directory with permission from Underwriters Laboratories Inc."
[This message has been edited by Tom (edited 02-01-2006).]
[This message has been edited by Tom (edited 02-01-2006).]
