Watlow EZ-ZONE PM PID - Manual (Page 114)

Watlow EZ-ZONE ® PM PID Controller • 111 • Appendix
Detection of and Rules Around Abnormal Sensor Conditions
Inputs Detection of Abnormal Conditions
Thermocouple
Shorted
No direct detection, Open loop firmware detection.
Open Yes, Parasitic pull-up
Reversed Yes, firmware detection
Current Source
Shorted
Range limiting only
Open Range limiting only
Reversed Range limiting only
Voltage Source
Open
Range limiting only
Shorted Range limiting only
Reversed Range limiting only
RTD
S1 open
Yes, pulled up.
S2 open Not implemented.
S3 open Yes, pulled up.
S1 short to S2 Yes, pulled up
S1 short to S3 Yes, pulled down to under range.
S2 shorted to S3 Not implemented, Possible, monitor S2 voltage.
S1 and S2 open Yes, pulled down to under range.
S1 and S3 open Yes, S1 pulled up.
S2 and S3 open Yes pulled up.
Thermistor
S1 open
Yes, pulled up to sensor over range.
S3 open Yes, pulled up to sensor over range.
S1 short to S3 Yes, pulled down to sensor under range.
S1 and S3 open Yes, S1 pulled up to sensor over range.
Troubleshooting Alarms, Errors and Control Issues (cont .)