Standard Operation Steps for Replacing Hot Runner Nozzle Thermocouples

Standardized replacement procedures are essential operation criteria for maintenance staff and can guaranty safe construction, precise installation, and a quick restart of production.

1. Shutdown power-off cooling: To avoid scald incidents, turn off the temperature control box's entire power supply, stop heating, and wait until the nozzle temperature falls below 60°C.

2. Document wiring marks: To prevent incorrect connections after replacement, take pictures of the positive and negative pole wiring sequence and terminal numbers.

3. Remove the old thermocouple by carefully loosening the fixing thread, pulling it out along the hole axis without twisting it too much, and cleaning the mounting hole of any remaining carbon deposits and other debris.

4. Examine the quality of the new parts: Verify that the model, length, and bending angle match exactly, as well as whether the probe and wire are undamaged.

5. Install and secure in place: Screw the thread tightly to guaranty close contact without a gap after inserting the new thermocouple to the standard depth.

6. Restore the wiring connection: Make sure there is no virtual connection or polarity reversal, secure terminal screws firmly, and connect wires strictly in accordance with the original markings.

7. Safety check before to power-on: Verify that there are no hidden hazards and look for wire extrusion, short circuit risk, and installation looseness.

8. Segmented trial heating: Use a low-temperature gradual heating mode, monitor temperature display stability, confirm a typical temperature rise without an alarm, and then formally enter production.

The one-time success rate of replacement work can be increased and installation errors can be significantly decreased by using the unified operating approach.