Safety Preparations Before Replacement: First, turn off the power to the hot runner system, hang a "Do Not Power On" sign, and wait for the temperature to drop below 60°C. To avoid burns, wear protective gloves that can withstand extreme temperatures.
Enter the Husky thermostat's system settings interface and temporarily turn down the heating output of the relevant thermocouple channel to avoid accidentally activating the heating coil during replacement.
Prepare a new thermocouple with the same model number as the original, a digital multimeter, an Allen wrench, high-temperature insulating tubing, and any other equipment or materials required. Confirm that the replacement thermocouple's length and diameter are identical to the original specs.
Remove the Old Thermocouple: Open the Husky thermostat's terminal box, mark the thermocouple's positive and negative terminals, release the terminal screws, and disconnect the compensating wires from the old thermocouple.
Remove the Old Thermocouple: Loosen the clamping nut on the thermocouple in the hot runner and carefully remove the damaged old thermocouple. If rust or adhesion is present, apply a loosening agent before disassembling. Do not force open the damaged hot runner plate.
Before installing a new thermocouple, ensure that its insulation resistance is ≥100MΩ, that the protective tube is free of fractures, and that the lead insulation is intact.
Slowly put the new thermocouple into the pre-drilled hole in the hot runner, making that the sensing end is totally in touch with the measuring point and that the insertion depth is proper. To secure the thermocouple, tighten the clamping nut.
Connect the thermocouple compensation wires to the corresponding terminals on the Husky thermostat, using the previously marked positive and negative terminals. Tighten the screws and gently pull the wires to ensure there are no loose connections. Ensure enough insulating protection.
After-Replacement Verification and Calibration: Measure the thermocouple circuit resistance and insulation resistance to ensure there are no shorts or loose connections. Then turn on the Husky thermostat and activate the heating output for the corresponding channel.
Start the temperature controller to increase the temperature. Watch the temperature display to ensure that it rises evenly and without any jumps. After the temperature has stabilised, execute PID self-tuning and complete the temperature offset calibration using the prior calibration technique. After ensuring that the temperature measurement accuracy satisfies the criteria, lock the parameters.
Run continuously for 30 minutes. If the temperature control system has no warnings and the temperature fluctuation is ≤±1℃, the replacement process is completed and the system can resume regular production operations.
This replacement procedure is entirely tailored to the features of the Husky hot runner temperature control system, preventing equipment damage during the replacement process and ensuring steady functioning of the following temperature control.
