GE M60 Instruction Manual page 428

GROUPED ELEMENTS
5.7.3.6 Undercurrent (ANSI 37)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  MOTOR  UNDERCURRENT
 UNDERCURRENT

5
The undercurrent function uses the source defined by the
currents must be configured on this source; otherwise, the undercurrent function is not operational. The element responds
to a per-phase current.
If the undercurrent function is enabled, a trip or alarm is initiated once the IA, IB, or IC current magnitude falls below the
pickup level for a time specified by the delay setting. For example, the undercurrent element can be used to detect loss-of-
load conditions. This can be especially useful for detecting process related problems.
The undercurrent element is active when the motor is running at speed 1, that is, when the motor status is running and
speed 2 is not employed or active.
UNDERCURRENT START BLOCK DLY
is starting. If not in the starting state, the motor status is indicated by the
under
SETTINGS  SYSTEM SETUP  MOTOR
The undercurrent element is active only when the motor is running and is blocked upon the initiation of a motor start for a
period of time specified by this setting. For example, this block delay can be used to allow 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.
UNDERCURRENT ALARM PICKUP
threshold less than the motor load current during normal operations.
UNDERCURRENT ALARM PICKUP DLY
to overcome any short lowering of the current (for example, during system faults).
UNDERCURRENT TRIP PICKUP
corresponding setting for the alarm stage.
UNDERCURRENT TRIP PICKUP DLY
overcome any short lowering of the current (for example, during system faults).
5-220
UNDERCURRENT

FUNCTION: Disabled
UNDERCURRENT START

BLOCK DLY: 0.50 s
UNDERCURRENT ALARM

PICKUP: 0.70 x FLA
UNDERCURRENT ALARM

PICKUP DLY: 2.00 s
UNDERCURRENT TRIP

PICKUP: 0.70 x FLA
UNDERCURRENT TRIP

PICKUP DLY: 1.00 s
UNDERCURRENT TRIP

RESET DLY: 1.00 s
UNDERCURRENT BLOCK:

Off
UNDERCURRENT TARGET:

Self-reset
UNDERCURRENT EVENTS:

Disabled
— This setting specifies the length of time to block the undercurrent function when motor
for information on using the
— This setting specifies a pickup threshold for the alarm stage. Set the alarm pickup
— This setting specifies a time delay for the alarm stage. Set the time delay long enough
— This setting specifies a pickup threshold for the trip stage. Set the pickup less than the
— This setting specifies a time delay for the trip stage. Set the time delay long enough to
Range: Disabled, Enabled
Range: 0.00 to 600.00 s in steps of 0.01
Range: 0.10 to 0.95 × FLA in steps of 0.01
Range: 0.00 to 600.00 s in steps of 0.01
Range: 0.10 to 0.95 × FLA in steps of 0.01
Range: 0.00 to 600.00 s in steps of 0.01
Range: 0.00 to 600.00 s in steps of 0.01
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
SYSTEM SETUP  MOTOR  MOTOR LINE SOURCE
MOTOR OFFLINE
MOTOR OFFLINE
M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
setting. Phase
operand. See the Motor section
operand for state determination.