Watlow PM LEGACY PM3 - Page 103

Watlow PM LEGACY™ Limit Controller • 103 • Appendix
Indication Description Possible Cause(s) Corrective Action
Alarm High
AL.h1
AL.h2
AL.h3
AL.h4
Sensor input above
high alarm set point
• Temperature is greater
than alarm set point
• Alarm is set to latching and
an alarm occurred in the
past
• Incorrect alarm set point
• Incorrect alarm source
• Check cause of over tem-
perature
• Clear latched alarm
• Establish correct alarm set
point
• Set alarm source to proper
setting
Error Input
Er.i1
Sensor does not pro-
vide a valid signal to
controller
• Sensor improperly wired or
open
• Incorrect setting of sensor
type
• Calibration corrupt
• Correct wiring or replace
sensor
• Match setting to sensor
used
• Check calibration of con-
troller
Ambient Error
Er.ab
Sensor does not pro-
vide a valid signal to
controller
• Ambient error - cold junc-
tion circuitry not working
• Return to factory for repair
Limit won’t
clear or reset
Limit will not clear or
reset with keypad or
digital input
• Sensor input is out of limit
set point range
• Limit set point is incorrect
• Digital input function is in-
correct
• Correct cause of sensor in-
put out of limit range
• Set limit set point to correct
trip point
• Set digital input function
and source instance
Limit Error
Li.E1
Limit state cannot be
determined due to
lack of sensor input,
limit will trip
• Sensor improperly wired or
open
• Incorrect setting of sensor
type
• Calibration corrupt
• Correct wiring or replace
sensor
• Match setting to sensor
used
• Check calibration of con-
troller
Limit Low
Li.L1
Sensor input below
low limit set point
• Temperature is less than
limit set point
• Limit outputs latch and re-
quire reset
• Incorrect alarm set point
• Check cause of under tem-
perature
• Clear limit
• Establish correct limit set
point
Limit High
Li.h1
Sensor input above
high limit set point
• Temperature is greater
than limit set point
• Limit outputs latch and re-
quire reset
• Incorrect alarm set point
• Check cause of over tem-
perature
• Clear limit
• Establish correct limit set
point