1 Scope

1.1 These requirements cover grounding monitor interrupters (GMI) that monitor the continuity of the grounding path of the electrical circuit to reduce the risk of electrical shock and intended for use in accordance with the NFPA 70^®, National Electrical Code^® (NEC^®).

NFPA 70^®, National Electrical Code^®, and NEC^® are registered trademarks of the National Fire Protection Association, Quincy, MA.

1.2 A GMI is intended for use in circuits rated 150 Vac or less to ground.

1.3 These requirements cover devices where the grounding path impedance is not greater than the ungrounded conductors path impedance.

1.4 A GMI functions monitoring grounding continuity. If grounding does not exist when an attempt is made to start using the equipment, the device does not energize the circuitry connected to its load terminals and interrupts the circuit under conditions where grounding is lost during operation.

1.5 A Type I GMI monitors and interrupts the ungrounded conductors when grounding is lost. It may also monitor voltage potential present on the grounding conductor and interrupt the ungrounded and grounded conductors.

1.6 A Type II GMI with a switched equipment grounding interrupter meets requirements of a type I GMI, and has the ability to monitor and interrupt the grounding conductor when potential is present on the grounding conductor.