When we use heat shrink packaging machine, there are some glitches that are very common, like slow temperature rise. Let us know its heating principle. The heater circuit is driven by the main power line through a magnetic switch and then to the electric heating tube, so we should first detect whether the magnetic absorption switch contact is normal or not.
1.the line is not through one phase, there will be the above phenomenon. If the magnetic switch is normal, then check the meter, see the ohmic and machine phase value is the same.
2.If normal, it should short circuited. As each phase are connected but circuit or the electric heating tube is still abnormal, you need to replace the heater.