GE 845 Instruction Manual page 341

CHAPTER 4: SETPOINTS
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845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
If the 3-phase VT uses a delta connection and FREQUENCY INPUT is set to J2-3VT, the
positive sequence voltage is used as the supervision voltage. In such condition, the true
supervision level is internally changed to 1/sqrt(3) of the user setting since the base of VT
here is the phase-phase voltage.
MINIMUM CURRENT
Range: 0.000 to 30.000 x CT in steps of 0.001 x CT
Default: 0.200 x CT
The setting sets the minimum value of current required on any phase to allow the
Underfrequency element to operate. The setpoint is used to prevent underfrequency
tripping during periods of light load, when this action would have an insignificant effect
on the system. A setting of zero is suspend current supervision.
BLOCK
Range: Off, Any operand from the list of FlexLogic operands
Default: Off
OUTPUT RELAY 3 (X)
Range: Do Not Operate, Operate
Default: Do Not Operate
EVENTS
Range: Enabled, Disabled
Default: Enabled
TARGETS
Range: Disabled, Self-reset, Latched
Default: Self-reset
PROTECTION
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