GE M60, Instruction Manual

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CHAPTER 5: SETTINGS GROUPED ELEMENTS
M60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-241
5
The
PHASE TOC1 PICKUP
setting can be reduced dynamically by a voltage restraint feature (when enabled). This is
accomplished via the multipliers (Mvr) corresponding to the phase-phase voltages of the voltage restraint characteristic
curve (see the figure); the pickup level is calculated as Mvr times the
PHASE TOC1 PICKUP
setting. If the voltage restraint
feature is disabled, the pickup level always remains at the setting value.
Figure 5-131: Phase time overcurrent voltage restraint characteristic
FUNCTION
— This setting enables and disables the phase time overcurrent protection element.
SIGNAL SOURCE
— Selects the signal source for the phase time overcurrent protection element.
INPUT
— Selects how phase current input quantities are interpreted by the M60. Inputs can be selected as fundamental
phasor magnitudes or total waveform RMS magnitudes as required by the application.
PICKUP
— Specifies the phase time overcurrent pickup level in per-unit values.
CURVE
— Selects the time inverse overcurrent curve style.
TD MULTIPLIER
— Specifies a multiple of the base curve shape specified by the
CURVE
setting. Programming this value to
zero results in an instantaneous response to all current levels above pickup.
RESET
— The “Instantaneous” reset method is intended for applications with other relays, such as most static relays, which
set the energy capacity directly to zero when the current falls below the reset threshold. The “Timed” reset method can be
used where the relay must coordinate with electromechanical relays.
VOLTAGE RESTRAINT
— Enables and disables the phase time overcurrent voltage restraint feature.
BLOCK A
— Assertion of the operand assigned to this setting blocks phase A of the phase time overcurrent element.
EVENTS
— Enables and disables the logging of phase time overcurrent events in the sequence of events recorder.