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RTD Sensor Alarm
The following summarizes some of the possible causes and solutions for a heat tracing RTD sensor reading alarm.
Communications Alarm
The following summarizes some of the possible causes and solutions for heat tracing communications alarms.
Circuit Fault Alarm
The following summarizes some of the possible causes and solutions for heat tracing circuit fault alarms.
Possible Cause
Recommended Solutions
RTD connections are wired improperly
or have become loose.
Confirm wiring and connections are correct.
RTD has failed open or has extremely
high resistance or RTD has failed
shorted or has very low resistance.
Perhaps lightning has damaged the sensor? Maybe the piping has had
some welding going on nearby? Maybe the RTD has gotten wet? Replace
RTD.
Possible Cause
Recommended Solutions
Improperly set controller address,
duplicate addresses, or improper
configuration of firmware/software.
Change controller address or reconfigure firmware/software.
Loose or open connection in RS485
line.
Recheck for continuity in all communication lines.
Too many modules in network.
Check network limitations versus actual configuration.
Too long of an accumulated
communication distance.
Consider the addition of a repeater.
Too many reflections of signal usually
caused by improper terminations in
network.
Add termination resistors as appropriate.
Possible Cause
Recommended Solutions
Upon initial installation start-up,
improper wiring of the relay or low
current in heater.
Confirm correct wiring and presence of the heater. Where normal operating
amperage is in range of 0 to 250 mA, disabling the Self-Test function or
adding multiple loops through the current sensing toroid may be required.
During daily operations; possibly
indicates relay contact failure.
If relay has failed, replace.
Breaker off.
Turn on breaker after conferring with operations manager.
