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5.4 Trips
In the event that the measured conditions of the heat trace circuit go beyond the
TRIP settings of the circuit, the circuit will trip, i.e. turn off. When a circuit trips,
the circuit will be deactivated, the corresponding tri-color LED will flash red, the
common TRIP digital output will annunciate and a corresponding message will
be displayed on the Alarm Line of the display. A TRIP event is different from an
ALARM event in that the heat trace circuit is deactivated and will remain
deactivated until the circuit is manually reset by the user.
For Temperature TRIPS pressing
once will acknowledge the TRIP causing
the circuit LED to stop flashing and stay solid red and the common TRIP digital
output to deactivate. To reset a high temperature TRIP and reactivate the
circuit,
must be pressed again.
For heater current and ground/earth fault TRIPs, pressing
will reset the TRIP,
cause the common TRIP digital output to deactivate, the circuit LED to stop
flashing red and the TCM2 will attempt to resume normal control.
If the conditions which caused the trip are still present, the circuit will TRIP
again.
All alarms, trips and acknowledgements are transmitted via RS-485.
Acknowledgements and resets can also be performed remotely from a TraceNet
Command system or through a plant DCS systems via ModBus commands.
See
Appendix A
for ModBus Memory Map.
See
Table 5.2
for a comprehensive explanation of alarm messages.
