nvent 910 Series Installation, Operating And Maintenance Instructions page 58

• Damaged cable insulation and/or moisture present
• Moisture in junction box
• Poor splice or termination
• Moisture provides conductive ground path which allows ground fault current
8.3.9 HIGH VOLTAGE
This alarms voltage levels that are greater than the HIGH VOLTAGE ALARM setting.
Cause of Alarm:
• Alarm setting too close to normal operating voltage
• Incorrect wiring
• Power surge
8.3.10 LOW VOLTAGE
This alarms voltage levels which are less than the LOW VOLTAGE ALARM setting.
Cause of Alarm:
• Alarm setting too close to normal operating voltage
• Damaged power cable
• Incorrect VOLTAGE TURNS RATIO
• "Brown-out" conditions
• Loss of power to the circuit
8.3.11 OVERCURRENT TRIP
If the controller is unable to start the cable due to high current or after attempting to soft start
it, the controller will trip its output switch off.
Cause of Alarm:
• Excessive in-rush current
• Incorrect wiring
• Damaged cable
8.3.12 SWITCH FAILURE
This alarm indicates that the controller senses current flow when the output switch should be
off.
Cause of Alarm:
• Some other device energized heat trace
• Output switch has failed "closed"
8.3.13 HTC RESET
This alarm is latched when power is restored after an interruption. Used to identify intermittent
power losses.
Cause of Alarm:
• Circuit breaker tripped
• Power line transient
8.3.14 POWER LIMITING
This alarm indicates that the solid state relay is limiting the average amount of power that is
applied to the trace circuit as defined by the MAXIMUM POWER setting.
Cause of Alarm:
• Power applied to trace circuit is being limited to the MAXIMUM POWER setting
8.3.15 C.B. LIMITING
This alarm indicates that the solid state relay is limiting the average current that is applied to
the trace circuit to the C.B. CURRENT RATING setting to protect the upstream heater circuit
breaker from tripping.
58 | nVent.com