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 doubleinsulation is provided@ but the use of a Class A ground-fault circuit-interrupter is not practical. 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. 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.
UL SUBJECT 943C-2012 history
2012UL SUBJECT 943C-2012 OUTLINE OF INVESTIGATION FOR SPECIAL PURPOSE GROUND-FAULT CIRCUIT-INTERRUPTERS (Issue 2)
2011UL SUBJECT 943C-2011 Outline of investigation for special purpose ground-fault circuit-interrupters