1 Scope

1.1 These requirements cover ground-fault circuit-interrupters intended for use in one of the following applications:

a)    Where the voltage to ground is greater than 150 volts and equipment grounding or double insulation is required by the National Electrical Code, ANSI/NFPA 70,

b)    Where the voltage to ground is 150 volts or less and equipment grounding or double-insulation is provided, but the use of a Class A ground-fault circuit-interrupter is not practical.

1.2 Ground-fault circuit-interrupters addressed by these requirements are divided into three classes, Class C, D and E, based upon voltage rating and the characteristics of the grounding circuit. Some are intended for use in circuits where grounding is not provided to the load but double-insulation is provided.

1.3 These ground-fault circuit-interrupters are intended to be applied on circuits as shown in Figure 1.1. The requirements for Class A ground-fault circuit-interrupters are in the Standard for Ground-Fault Circuit-Interrupters, UL 943.

1.3 Figure 1.1Application of GFCIs