In industrial production, cartridge heater failures will directly lead to equipment shutdown and production interruption, causing certain economic losses. Mastering the common fault types, detection methods and maintenance skills of cartridge heaters, can quickly find the fault cause, carry out targeted maintenance or replacement, shorten the downtime, and restore production in a timely manner. Based on practical maintenance experience, summarizing the common faults of cartridge heaters and corresponding detection and maintenance methods, can help maintenance personnel quickly troubleshoot and improve work efficiency.
Common fault 1: The heater does not heat, no heat output. This is the most common fault, mainly caused by circuit problems or internal resistance wire breakage. Detection method: first use a multimeter to measure the on-off of the heater terminal, if the resistance value is infinite, it means the internal resistance wire is broken, and the heater needs to be replaced directly; if the resistance value is normal, check the external circuit, including whether the power supply is normal, whether the terminal is loose, whether the fuse is blown, whether the temperature controller is faulty, and repair the circuit or replace the faulty components. In addition, poor contact between the heater and the installation hole, excessive gap leading to no heat transfer, will also make it feel that there is no heating, check the installation gap and re-install.
Common fault 2: The heater heats unevenly, local overheating or insufficient heating. This fault is mostly caused by internal resistance wire winding uneven, loose internal insulation material, or installation gap uneven. Detection method: observe the surface of the heater, if there is local redness, it means local overheating, mostly due to poor heat transfer or internal damage. Check whether the installation hole is smooth, whether the gap is uniform, clean the hole and re-install with heat-conducting silicone grease; if the fault still exists, it means the internal structure is damaged, and the heater needs to be replaced. In addition, unreasonable watt density selection, too high local watt density, will also lead to uneven heating, need to re-select the appropriate heater.
Common fault 3: Heater electric leakage, equipment has electric shock feeling. This is a safety hazard fault, mainly caused by damaged internal insulation layer, moisture ingress or sheath perforation. Detection method: use a megohmmeter to measure the insulation resistance between the heater terminal and the sheath, if the insulation resistance is lower than 1MΩ, it means insulation damage. If it is caused by moisture ingress, the heater can be taken out for low-temperature drying (100-150℃ for 2-3 hours), and then test the insulation resistance, if it returns to normal, it can be reused; if it is caused by sheath perforation or insulation layer damage, the heater must be replaced immediately to avoid electric shock accidents. At the same time, check whether the equipment grounding is reliable, strengthen grounding protection.
Common fault 4: Heater short service life, frequent burnout. This fault is related to selection, installation and use environment. Detection method: first check whether the watt density is too high, whether the use voltage matches, if the watt density is too high, replace the heater with low watt density; if the voltage is mismatched, replace the heater with corresponding rated voltage. Check whether the installation gap is too large, leading to poor heat dissipation and overheating burnout, re-process the installation hole to ensure the gap is appropriate. Check whether the use environment is corrosive, whether the sheath material is corroded, replace the heater with corrosion-resistant sheath material. In addition, frequent start-stop and temperature fluctuations are too large, will also lead to thermal fatigue and burnout, equip a PID temperature controller to stabilize the temperature.
Common fault 5: Heater terminal overheating, lead wire insulation melting. This fault is mostly caused by loose terminal screws, excessive current or lead wire too thin. Detection method: tighten the terminal screws to ensure good contact; check whether the heater power matches the circuit, whether the current is too large, replace the appropriate lead wire (thick wire diameter, high-temperature resistant material); avoid the lead wire being too close to the high-temperature area, re-route and fix the lead wire.
Daily maintenance is the key to reduce heater failures. Regularly clean the heater surface and installation hole dust, oil and other impurities, keep the heat transfer smooth; regularly check the terminal tightness, lead wire integrity, replace aging lead wire in a timely manner; test the insulation resistance regularly, deal with moisture and corrosion in a timely manner; avoid dry burning, overload use and frequent start-stop. For heaters in harsh environments, increase the frequency of maintenance and inspection.
When the heater cannot be repaired, such as resistance wire breakage, sheath perforation, serious insulation damage, it should be replaced immediately, and do not continue to use with faults to avoid safety accidents and greater equipment damage. When replacing, select the heater with the same parameters and better quality, and install it in accordance with the specifications to ensure normal operation.
Mastering cartridge heater fault detection and maintenance skills, can quickly deal with various common faults, reduce equipment downtime, improve production efficiency. At the same time, strengthening daily maintenance, can reduce the occurrence of faults, extend the service life of heaters, reduce maintenance and replacement costs, and ensure the stable operation of industrial production.
