During equipment operation, the outer wall of the electric heating ring may become locally red, and a burnt smell may come from the lead terminals. After disassembly and inspection, the resistance wire is found to be oxidized and thinned—such phenomena are often related to supply voltage deviating from the rated value. When accepting goods or analyzing faults, procurement personnel can first check the on-site voltage fluctuation range.
The electric heating ring is designed according to rated voltage. When the working voltage exceeds the rated value by 10% for a long time, the resistance wire temperature rises, the oxidation rate accelerates, and the service life is shortened accordingly; if the voltage is too low, heating is insufficient, affecting the process cycle. During procurement, it is necessary to confirm the on-site power supply quality and, if necessary, stipulate the voltage adaptation range in the contract.
This heating ring can be equipped with a built-in K-type or J-type thermocouple as needed, and the lead specifications and threaded hole positions are configured according to the customer's temperature control system. Procurement personnel should provide the temperature controller model, interface type, and installation space dimensions to avoid situations after delivery where the thermocouple graduation number does not match or the thread does not fit.
If the working conditions are mainly medium and low temperature with frequent disassembly and assembly, the cast aluminum solution can be evaluated first; if the heating section is narrow and a higher surface temperature is required, the ceramic ring is more adaptable in terms of power density. The DJR-420 model adopts a ceramic core structure and is suitable for section heating of injection molding machine barrels, extruders, and similar equipment.
Check whether the nameplate voltage and power are consistent with the ordering agreement; check the lead length, terminal form, and thermocouple lead markings; measure and record the cold resistance value as a baseline for subsequently judging the condition of the resistance wire.
