Extruder Trouble Shooting Guide

Problem Possible Cause Possible Solution
Motor overload of vacuum pump Too much water is being supplied to the pump Adjust water supply untill maximum vacuum is achieved with minimum water supply
Current draw exceeds power of motor Check the motor data tag
Too less water is being supplied to the pump Adjust water supply untill maximum vacuum is achieved with minimum water supply
The exhaust line has a restriction or is not connected to a vent open to the atmosphere Unclog the line / connect it to an open vent
Vacuum too low Water too warm Adjust water temperature (cold water produces more vacuum)
Barrel Heat Zone will not reach the set point Heater band burned out Replace heater band
Pyrometer is not energized when the temperature drops below the set point Replace the pyrometer
Mercury contactor in control cabinet not energized or faulty Replace mercury contactor
Overload protection circuit breaker for the individual heater zone is not energized Energize circuit breaker for appropriate zone
Thermocouple is not seated in the thermocouple well Seat the thermocouple well again
Thermocouple or heater bands reversed at their zones (Example: Zone 2 thermocouple sensing a low temperature in Zone 2 and adding heat to Zone 1 Switch thermocouple or heater band to the proper zone
Cooling control solenoid stuck in the open position Replace control solenoid
Heat zone overriding the set point Pyrometer does not de-energize when the temperature exceeds the set point Replace the pyrometer
Pressure relief valve stuck in the open position Replace the relief valve
Thermocouple or heater bands reversed at their zones (Example: Zone 2 thermocouple sensing a low temperature in Zone 2 and adding heat to Zone 1 Switch thermocouple or heater band to the proper zone
Insufficient water flow through the heat exchanger. Heat exchanger is clogged or the globe valve is closed Check hoses, unclog heat exchanger or open globe valve. Replace heat exchanger
Solenoid for zone’s fluidcontrol not opening Replace defective solenoid
Defective pump, motor, thermal overload or coupling Replace defective pump, motor or coupling
Oil system plugged or clogged Change oil filter. Clean and flush oil systems
Screw temperature will not reach the set point Heater band is burned out Replace the heater band
Thermocouple is defective Replace the thermocouple
Pyrometer : Not energizing the mercury contactor Replace the pyrometer
Cooling solenoid continuously energized Replace the solenoid
Mercury contactor is defective Replace the mercury contactor
Cooling fluid solenoid valve is stuck open Replace the solenoid valve
Insufficient fluid flow: clogged filter Change the filter
Faulty pump, motor or coupling Replace
Oil system plugged or clogged Change oil filter. Clean and flush oil system
Screw temperature overriding the set point Pyrometer does not deenergize when the temperature exceeds the set point Replace the pyrometer
Thermocouple near the flow meter outlet is defective Replace the thermocouple
Insufficient water flow through the heat exchanger Unclog or replace heat exchanger
Water solenoid supply not energized or stuck in the close position Replace the solenoid
Cooling fluid solenoid valve stuck closed Replace solenoid valve
Pressure relief valve stuck open Replace relief valve
Filter clogged Change filter
Faulty pump, motor, thermal, overload or coupling Replace
Oil system plugged or clogged Change oil filter. Clean and flush oil system
Insufficient vacuum for venting Insufficient water flow Check hose
Check hose clamps and manifold bolts for tightness
Check O-rings in sight glass
Clean out gate valve
Change the filter
Check solenoid valve
Check pump, motor and coupling
Excessive vibration Poor coupling alignment at motor Realign coupling
Defective bearing in the reduction gearbox Replace the bearing
Defective bearing in the motor Replace the bearing
Thumping noise in the rear of the machine Defective bearing in the distributor gearbox Replace defective bearing
Rough spot on gear inside distributor gearbox Remove rough spot on gear
Poor coupling alignment between the reduction and distributor gearboxes Realign coupling
Erratic drive RPM Faulty speed board in DC drive Replace speed board
Faulty current board in DC drive Replace current board
Faulty input voltage to DC drive Correct the voltage supply
Excessive current being drawn from the drive Check / Replace DC drive motor
Starve feeder auger does not operate The reference potentiometer is set to zero Reset or replace the potentiometer
The control is not receiving the start input due to debris in the start button Clean out control buttons
The starting coil has not received an output from the control or is faulty Check the connection and/or replace the starting coil
The drive fuses have blown Replace the fuses
The feeder drive is faulty Replace the motor
The armature fuse has blown Replace the fuse
Optional signal conditioned card used for slaving the main extruder motor and the feed auger has failed Replace the card
Starve feeder auger operates but will not achieve full speed Main motor potentiometer is set low or to zero Increase the setting of the main motor potentiometer
The entire extruder is overheating The water saver solenoid has failed in the closed position or blown in related fuse Check the solenoid valve and/or replace the fuse
The cooling water supply to the extruder is dirty causing restricted flow or the supply pressure is insufficient Change the filter or check the supply line for leaks