DESCRIPTION
GE
GROUND-FAULT RELAY
The
GE IC2820A102 is a fast-acting hand-reset relay
designed to interrupt control power of a line contactor
on sensing a ground current in the lines to an ac
motor load or other ac equipment. If a ground fault
can be removed within a few cycles of its initiation,
damage to a motor or other ac equipment can be minimized.
For example, on a large induction or synchronous
motor when an insulation failure occurs to ground,
the fault current will be removed before damage
is done to the laminations, thus making it possible
to repair the motor at a minimum of expense and
downtime.
The
GE relay is designed for use with a window-type
current transformer where the three load leads (for
a 3-phase system) are placed through the window.
When a ground fault occurs, the vector sum of the
currents in the load cables will not equal zero
and this sum will cause a current in the secondary
of the current transformer that will energize the
relay coil. This current will actuate the relay
to ‘‘TRIP’’, opening the
normally closed contacts, and closing the normally
open contacts shorting out the rectifier and coil.
The trip lever holds the relay in this position
until the lever is moved in a counterclockwise direction
to the ‘‘RESET’’ position.
GE
DIFFERENTIAL RELAY
The
GE IC2820A102A differential relay detects any difference
in current going in and out of each phase of a wye-connected
motor. The current difference will trip the differential
relay and shut down the motor by opening the motor-line
contactor. |
