Phase Current Overload - GE 239 Instruction Manual

7.4

Phase Current Overload

7–98
Courtesy of NationalSwitchgear.com
1. Alter the following setpoints:
S4: PROTECTION\PHASE CURRENT\OVERLOAD\OVERLOAD CURVE NUMBER: 4
S2: SYSTEM SETUP\CT INPUTS\PHASE CT PRIMARY: 100A
S2: SYSTEM SETUP\MOTOR DATA\MOTOR FULL LOAD CURRENT: 50A
S5: TESTING\TEST CONFIGURATION\DISABLE START PROTECTION: YES
2. Before beginning this test it is necessary to ensure that the thermal capacity value in
A2: METERING\MOTOR CAPACITY
this value to 0% by shorting together the Emergency Restart switch terminals (39, 44)
momentarily. The Emergency Restart input will not function if any phase or ground
current is injected.
3. Inject a current of 10 A into all three phases. The relay will display a current value of:
displayed current actual injected current
=
This represents four times
CURRENT setpoint. Therefore, based on a 400% overload and curve #4, the trip relay
should activate after a time of 23.3 seconds after the overload is first applied.
4. After the overload trip has occurred, verify by viewing
that the thermal capacity used is 98% to 100%. The thermal capacity value
CAPACITY
will start decreasing as soon as the overload condition is removed and therefore may
vary depending upon how quickly after the overload trip the
A2: METERING\MOTOR CAPACITY
A2: METERING\MOTOR CAPACITY
and press the reset key to reset the unit.
is 0% to obtain a proper trip time. If required reset
PHASE CT PRIMARY
× ----------------------------------------------- -
5 A
S2: SYSTEM SETUP\MOTOR DATA\MOTOR FULL LOAD
A2: METERING\MOTOR
message is viewed. After viewing
, momentarily short the Emergency Restart terminals
239 MOTOR PROTECTION RELAY – INSTRUCTION MANUAL
CHAPTER 7: TESTING
100 A
× ------------- -
10 A 200 A
= =
5 A