Why does the wiring of the heating rod in the hot runner mold often burn out

If the wiring always burns out, there are generally two situations:
1. Poor contact at the wiring of the heater, it is best to replace it with a terminal adapter.
2. The output current of the temperature controller used is the maximum current, with a relatively large impact, and it is in a switching state at the wiring, which is prone to aging.
Analysis can be conducted from these two aspects.