GE M60 Instruction Manual page 277

5 SETTINGS
element is active only when the motor is running at speed 2 and is blocked upon the initiation of a motor start for a
period of time defined by the
pumps to build up head before the undercurrent element trips or alarms). A value of 0 specifies that the feature is not
blocked from start. For values other than 0, the feature is disabled when the motor is stopped and also from the time a
start is detected until the time entered expires.
• SPEED2 U/CURR ALARM PICKUP: This setting specifies a pickup threshold for the alarm stage. The alarm pickup
threshold should be less than the motor load current during normal operations.
• SPEED2 U/CURR ALARM PICKUP DLY: This setting specifies a time delay for the alarm stage. The time delay
should long enough to overcome any short lowering of the current (for example, during system faults).
• SPEED2 U/CURR TRIP PICKUP: This setting specifies a pickup threshold for the trip stage. This setting should be
less than the corresponding setting for the alarm stage.
• SPEED2 U/CURR TRIP PICKUP DLY: This setting specifies a time delay for the trip stage. This time delay should be
long enough to overcome any short lowering of the current (for example, during system faults).
• SPEED2 U/CURR TRIP RESET DLY: This setting specifies a time delay to reset the trip command. This time delay
should be long enough to allow the breaker or contactor to disconnect the motor.
• SPEED2 U/CURR BLOCK: This setting specifies an operand used to block the speed 2 undercurrent function. A panel
cutoff switch or other user specified condition is typically used to block the function.
SETTING
SPEED2 U/CURR BLOCK
= Off
SETTING
SPEED2 U/CURR START
BLOCK DLY
FLEXLOGIC OPERANDS
T
PKP
MOTOR OFFLINE
TIMER
MOTOR STATUS
1 sec.
Switched to speed 2
SETTING
SPEED 2 MOTOR SOURCE
= Ia magnitude
= Ib magnitude
= Ic magnitude
GE Multilin
SPEED2 U/CURR START BLOCK DLY
SETTING
SPEED2 U/CURR ALARM
PICKUP
AND
RUN
0
IA_mag < PICKUP
IB_mag < PICKUP
IC_mag < PICKUP
0 SETTING
SPEED2 U/CURR TRIP
PICKUP
RUN
IA_mag < PICKUP
IB_mag < PICKUP
IC_mag < PICKUP
Figure 5–69: SPEED 2 UNDERCURRENT LOGIC
M60 Motor Protection System
5.6 GROUPED ELEMENTS
setting (for example, this block may be used to allow
SETTINGS
SPEED2 U/CURR ALARM
PICKUP DLY
SPEED2 U/CURR TRIP
PICKUP DLY
SPEED2 U/CURR TRIP
RESET DLY
T
PKP
OR
0
T
PKP
T
RST
OR
5
FLEXLOGIC OPERAND
U/CURR SP2 ALARM OP
FLEXLOGIC OPERAND
U/CURR SP2 TRIP OP
FLEXLOGIC OPERANDS
U/CURR SP2 ALARM PKP
U/CURR SP2 TRIP PKP
833022A1.CDR
5-139