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PT UNIT USER MANUAL
APRIL 2023 www.eaton.com.cn
5.2 Digital Input (DI)
The PT25 trip unit supports 2 sets of 220VAC digital inputs. The corresponding status value will be written upon receiving
external 220VAC signal inputs. The status value can be read via Modbus communication or through the PTM software.
5. Relay and Digital Input (PT25 only)
Function name
Description of relay operation
“The relay will close when...”
“The relay will open when ....”
Mechanical Fault Trip
a mechanical fault occurs and is disengaged, the
mechanism position is in the open position, but there is
measurable current
the fault is removed
Mechanical Fault Alarm
a mechanism fault alarm occurs (TA fault, mechanism
open, but there is measurable current)
Relevant fault is removed
Electrical Fault Alarm
electrical fault (configuration reading errors, clock faults,
watchdog faults, breaker health alarm) alarm has occurred Relevant fault is removed
Over-voltage Trip
over-voltage trip is active and over-voltage trip has
occurred
RESET button is pressed or communications reset command received
Over-voltage Alarm
over-voltage alarm is active and over-voltage alarm has
occurred
RESET button is pressed or communications reset command received
Under-voltage Trip
under-voltage trip is active and under-voltage trip has
occurred
RESET button is pressed or communications reset command received
Under-voltage Alarm
under-voltage alarm is active and under-voltage alarm has
occurred
RESET button is pressed or communications reset command received
Over-frequency Trip
over-frequency trip is active and over-frequency trip has
occurred
RESET button is pressed or communications reset command received
Over-frequency Alarm
over-frequency alarm is active and over-frequency alarm
has occurred
RESET button is pressed or communications reset command received
Under-frequency Trip
under-frequency trip is active and under-frequency trip
has occurred
RESET button is pressed or communications reset command received
Under-frequency Alarm
under-frequency alarm is active and under-frequency
alarm has occurred
RESET button is pressed or communications reset command received
Voltage Unbalance Trip
voltage unbalance trip is active and voltage unbalance trip
has occurred
RESET button is pressed or communications reset command received
Voltage Unbalance Alarm
voltage unbalance alarm is active and voltage unbalance
alarm has occurred
RESET button is pressed or communications reset command received
Current Unbalance Trip
current unbalance trip is active and current unbalance trip
has occurred
RESET button is pressed or communications reset command received
Current Unbalance Alarm
current unbalance alarm is active and current unbalance
alarm has occurred
RESET button is pressed or communications reset command received
Reverse Power Trip
reverse power trip is active and reverse power trip has
occurred
RESET button is pressed or communications reset command received
Reverse Power Alarm
reverse power alarm is active and reverse power alarm
has occurred
RESET button is pressed or communications reset command received
Phase Sequence Trip
phase sequence trip is active and phase sequence trip
has occurred
RESET button is pressed or communications reset command received
Phase Sequence Alarm
phase sequence alarm is active and phase sequence
alarm has occurred
RESET button is pressed or communications reset command received
Phase Loss Trip
phase loss trip is active and phase loss trip has
occurred
RESET button is pressed or communications reset command received
Phase Loss Alarm
phase loss alarm is active and phase loss alarm has
occurred
RESET button is pressed or communications reset command received
Power Demand Trip
power demand trip is active and power demand trip
has occurred
RESET button is pressed or communications reset command received
Power Demand Alarm
power demand alarm is active and power demand
alarm has occurred
RESET button is pressed or communications reset command received
OFF
relay is disabled
relay is disabled
