Troubleshooting

SYMPTOM
POSSIBLE CAUSE / RECOMMENDED ACTION
Equipment won’t start
  • E-Stop Active / Check for E-stop buttons or pull cables in tripped position & reset
  • Overtemperature Alarm Active / Check for over-temp condition / Reset device
  • Output Power not Enabled / Press Output Power Enable button on control panel
  • Door Open or Limit Switches not Functioning / Some equipment has doors that must be closed for equipment to operate, check that all doors are properly closed and latched and all limit switches activated / Replace limit switches if needed
One heater not functioning
  • Broken heater / Measure resistance of heater and replace if necessary, with power OFF.  Broken heater will be an open circuit.

Multiple heaters not functioning

  • Broken heater / Measure resistance of heaters and replace if necessary with power OFF.
  • Loose heater wires at terminal blocks / Check and tighten wiring with power OFF.
  • Heater section fuse blown / Check for shorts to ground / Replace fuse
  • SCR or SSR open/short circuit / replace SCR or SSR.
  • Bad thermocouple / replace as required.
Heater wiring terminal burned off
  • Steel or brass screw used / Replace with stainless steel screw and nut
  • Wire strands missing at terminal / Re-strip and terminate wire
  • Loose terminal / Replace components and tighten
  • For shortwave heaters check that cooling blowers are functional / Replace as needed.
No temperature is indicated
  • Verify the cable connection of the thermocouple to the PLC controller has not been crimped, damaged, or loosened.
The incorrect temperature is indicated
  • Verify that the thermocouple is properly positioned.
  • Verify that the sensor measurements are not being affected by electromagnetic interference (EMI). A test is to turn on/off-the potential sources of EMI and track the sensor results.
  • If temperature indicated is decreasing, check for reversed polarity of thermocouple(s) / correct polarity (type “K”) is yellow (+) and red (-).
  • If temperature is indicated but lower than expected, check that there are no loose or shorted leads in the wiring path.
Heaters stuck on
  • SCR or SSR fused closed / Shut off system power and check SCR or SSR for continuity across load terminals.  Replace as necessary.
  • Improper signal sent to power controller / Check for DC voltage signal into power controller when program is not running.  If present, check for crossed wires or damaged PLC I/O
PLC screen not operating
  • Improper electrical supply / Ensure 24VDC power supply into PLC / Check that Control Power Switch is ON
  • Program frozen or corrupted / Restart PLC.  If problem persists, reload program back onto PLC
  • Control panel enclosure overheated / Check filters for clogs / Check fans & A/C units for functionality / Replace & clean as needed
Conveyor not running
  • Drive faulted / Check faults at HMI screen / Reset fault if present
  • Conveyor fuse blown / Check that conveyor is not bound up / Replace fuse
  • Belt or chain broken / Check for breaks and replace as needed
Blower Fault – No Pressure Detected
  • Pressure sensor fault / Check for loose wiring / Replace sensor
  • Blower drive belt broken / Check and replace as required
  • Inlet or outlet blocked / Check filters / Clean if necessary
Overtemperature Alarm
  • Heaters stuck on / See previous section for troubleshooting tips
  • Exhaust set too low / Turn up exhaust blower or open exhaust dampers to increase draw
  • Heater setpoint too high / See equipment manual for recommended maximum temperature