TM 5-3895-374-24-1
SHIPPING DAMAGE, HANDLING & STORAGE
The GC-100 Ground Fault Relay is designed for Industrial environments Reasonable care should be exercised in handling
and storage to protect the device from excessive mechanical shock, humidity, or temperature Do not drop device Storage
temperatures should be less than 200F but more than -10°F The relay should be stored in Its original shipping carton until
ready for installation when not supplied as an integral part of other electrical apparatus such as a switchboard or
panelboard
Examine all components carefully for concealed shipping damage upon receipt of the equipment If damage or loss is
discovered, file a claim with the delivering carrier Immediately, and notify the nearest Square D field office Arrange for
repair or replacement through your local Square D office before returning any components to the factory
GROUNDED POWER SYSTEMS
The GC-100 Ground Fault Relay is intended for use only on power systems which include a grounded conductor (neutral
or grounded phase) The grounded conductor must be grounded at the service equipment, but the neutral may or may not
be used In the feeder or branch circuits.
SYSTEM OPERATION
A block diagram of the complete system including the Sensor, Ground Fault Relay, Monitor Components, and the
Disconnect Trip Coil Is shown in Figure 1. When circuit conditions are normal, the currents from all the phase conductors
and neutral (if used) add up to zero and the Sensor produces no signal When any ground fault occurs, however, the
currents add up to equal the ground fault current and the Sensor produces a signal proportional to the ground fault. This
signal Is sensed by the Ground Fault Relay and used to Initiate timing and other functions
(page 3-89)
