GE MOTOR MANAGER 2 Instruction Manual page 48

4.3 S2 PROTECTION
GROUND FAULT ALARM:
DLY ON START: 10 s
GROUND FAULT TRIP
LEVEL: OFF %CT
4
OR
GROUND FAULT TRIP
LEVEL: OFF A
GROUND FAULT TRIP
DELAY ON RUN: 1.0 s
4-14
Range: 1 to 60 seconds; Step: 1 second
This delay is used when the motor is in a STARTING condition. If the
ground current is equal to or above the GROUND PRIMARY ALARM PICKUP
setpoint value and remains this way for the time delay programmed in
this setpoint while the motor is starting, the alarm relay will activate and
the GROUND ALARM message will be displayed.
When the phase current increases from 0, this delay is
used until the MM2 determines whether the motor is RUN-
NING or STARTING.
NOTE
Refer to the ACCELERATION TIME setpoint in Section 4.3.7: LOAD PRO-
TECTION for details on how the MM2 detects a start condition.
Range: 3 to 100% CT or OFF; Step: 1%
This message will appear if the GROUND FAULT CT INPUT is set to 5A SEC
CBCT or 5A RESIDUAL. Some leakage current will always flow between the
3 phases and ground due to capacitance, insulation, resistance, etc. On
resistance limited ground systems, the value selected must be below the
maximum resistance limited current that can flow or a trip will never
occur. If no optimum value is known, monitor actual leakage current then
enter a current somewhat above this value. Ground Fault Trips at a later
time would indicate a deterioration in the system and insulation integrity
should be verified. Persistent, high values of leakage current pose a
threat to personnel and equipment and should not be left unchecked. If
the 5A CBCT RESIDUAL value is selected, the level is calculated as a per-
centage of the G/F CT PRIMARY setting; if the 5A RESIDUAL value is
selected, the level is calculated as a percentage of the PHASE CT PRIMARY
setting.
Range: 0.5 to 15.0 A, "0.5 A MAX", or OFF; Step: 0.5 A
This message will appear if the Ground Fault CT Input is set to 50:0.025
CBCT. See description for GROUND FAULT TRIP LEVEL (%CT) for details.
When set to 0.5 A MAX, the MM2 will trip at less than 0.5 A.
Range: 0.0 to 10.0 seconds; Step: 0.1 second
This delay is used when the motor is in a RUNNING condition. If the
ground current is equal to or above the GROUND PRIMARY TRIP PICKUP
setpoint value and remains this way for the time delay programmed in
this setpoint while the motor is running, the assigned relay(s) will activate
and the CAUSE OF TRIP: GROUND FAULT message will be displayed.
When the phase current increases from 0 A, the GROUND
TRIP DELAY ON START setpoint below is used until the MM2
determines whether the motor is RUNNING or STARTING.
NOTE
Refer to the ACCELERATION TIME setpoint in Section 4.3.7: LOAD PRO-
TECTION for details on how the MM2 detects a start condition.
MM2 Motor Manager 2
4 SETPOINTS
GE Power Management