How to solve the temperature control failure of hot runner system?

The solutions to the temperature control failure of the hot runner system are as follows:
The temperature is too high
Check the thermostat
Use professional temperature calibration equipment to calibrate the thermostat to check whether the deviation between the displayed temperature and the actual temperature is within the allowable range. If the deviation is too large, the thermostat needs to be debugged or replaced with a new one.
Check whether the parameter settings of the thermostat are correct, such as heating cycle, control accuracy and other parameters, to ensure that they meet the requirements of the hot runner system.
Check the heating element
Use a multimeter to measure the resistance value of the heating element and compare it with the nominal value. If the resistance value is significantly smaller, there may be a short circuit fault and the heating element needs to be replaced.
Check whether the installation position of the heating element is correct and whether it is in close contact with the heating part of the hot runner system. If there is a gap, it will affect the heat transfer and cause local overheating. The heating element needs to be reinstalled to ensure that it fits well with the heating part.
Confirm the thermocouple
Check whether the installation position of the thermocouple is accurate. It should be installed in a position that can accurately reflect the actual temperature of the hot runner, and avoid installing it in a dead corner or a place affected by external interference.
Check if the thermocouple circuit is damaged, short-circuited or open-circuited. If so, replace the circuit. At the same time, ensure that the connection between the thermocouple and the temperature controller is firm and not loose.
Temperature is too low
Detect heating element
For aging heating elements, their resistance value usually increases, resulting in a decrease in heating power. Measure the resistance value with a multimeter. If the resistance value is much larger than the nominal value, the heating element should be replaced in time.
Check the power supply line of the heating element to see if there are problems such as poor contact, open circuit or short circuit. If so, repair or replace the power supply line to ensure that the heating element can obtain a stable voltage normally.
Troubleshooting thermocouples
Use a multimeter to check whether the thermoelectric potential of the thermocouple is normal. If the thermoelectric potential is abnormal, it means that the thermocouple is damaged and needs to be replaced with a new thermocouple.
Check whether the installation of the thermocouple is loose. If looseness causes inaccurate measurement, the thermocouple needs to be reinstalled and fixed to ensure that it is in close contact with the measurement point.
Check the power supply system
Use a voltmeter to measure whether the power supply voltage is stable and whether it is within the rated working voltage range of the hot runner system. If the voltage is too low, check the power transformer, line voltage drop and other issues, and adjust the power supply system if necessary to ensure that the voltage is stable within the normal range.
Check whether the three-phase current of the power supply system is balanced. If there is a phase loss or current imbalance, the heating element will not work properly. Check the power switch, contactor and other equipment to eliminate the fault and restore normal power supply.