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CHAPTER 5: SETPOINTS
489 GENERATOR MANAGEMENT RELAY – INSTRUCTION MANUAL
5–89
5.10.3 Thermal Elements
SETPOINTS
ZV
S9 THERMAL MODEL
ZV
THERMAL ELEMENTS
Once the thermal model is setup, an alarm and/or trip element can be enabled. If the
generator has been offline for a long period of time, it will be at ambient temperature and
thermal capacity used should be zero. If the generator is in overload, once the thermal
capacity used reaches 100%, a trip will occur. The thermal model trip will remain active
until a lockout time has expired. The lockout time will be based on the reduction of thermal
capacity from 100% used to 15% used. This reduction will occur at a rate defined by the
offline cooling time constant. The thermal capacity used alarm may be used as a warning
indication of an impending overload trip.
1 THERMAL
[
Z
]
ELEMENTS
THERMAL MODEL
ALARM: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN ALARM
RELAYS (2-5): ---5
Range: Any combination of Relays
2 to 5
MESSAGE
THERMAL ALARM
LEVEL: 75% Used
Range: 10 to 100% Used in steps of 1
MESSAGE
THERMAL MODEL
ALARM EVENTS: Off
Range: On, Off
MESSAGE
THERMAL MODEL
TRIP: Off
Range: Off, Latched, Unlatched
MESSAGE
ASSIGN TRIP
RELAYS (1-4): 1---
Range: Any combination of Relays
1 to 4