Cartridge heaters are prone to various faults during long-term industrial use, such as no heating, slow heating, frequent burnout, electric leakage, uneven heating, etc. These faults will directly affect the normal operation of production equipment, reduce production efficiency, and even cause safety accidents. Many industrial users lack professional fault diagnosis knowledge, and can only blindly replace heaters when faults occur, increasing costs and failing to solve the root cause. This article summarizes common faults of cartridge heaters, detailed diagnosis methods and quick solutions, helping users quickly troubleshoot and restore normal production.
The most common fault is that the cartridge heater does not heat or heats weakly. The first step of diagnosis is to check the power supply and circuit, use a multimeter to test whether the input voltage is normal, whether the circuit is connected, whether the terminal is loose, burnt or short-circuited. Loose terminals and poor contact are the most common causes, which can be solved by tightening the terminals and replacing damaged wires. If the circuit is normal, test the resistance of the heater with a multimeter. If the resistance is infinite, it means the internal heating wire is broken; if the resistance is too small, it means the internal short circuit. In this case, the heater needs to be replaced. If the resistance is normal but does not heat, it may be that the internal insulating powder is loose and the heat transfer is poor, and the heater also needs to be replaced.
The fault of frequent burnout of cartridge heaters is also very common, and the root causes are various and need to be diagnosed one by one. First, check the installation clearance, excessive clearance between the heater and the installation hole leads to poor heat dissipation, heat accumulation inside the heater, causing the heating wire to burn out. The solution is to reprocess the installation hole, control the unilateral clearance within 0.05mm, and ensure tight fit. Second, check the power matching, excessive power selection leads to high power density, long-term over-temperature operation, easy burnout. Calculate the required power accurately according to the demand, and replace the heater with appropriate power. Third, check the heat dissipation conditions, the heated mold or component has poor heat dissipation, or the heater is exposed in the air for a long time, leading to overheating. Optimize the heat dissipation structure, ensure that the heater is fully inserted into the installation hole, and add heat preservation materials. Fourth, frequent thermal cycles, frequent start-stop operation accelerates thermal fatigue of the heating wire. Adjust the operation mode, use a temperature controller to keep constant temperature, and avoid frequent start-stop. Fifth, poor product quality, inferior materials and processes of the heater itself, replace with high-quality cartridge heaters.
Electric leakage is a dangerous fault of cartridge heaters, which must be solved in time. The main reason is that the internal insulation performance is reduced, and moisture or impurities enter the interior. Use a megohmmeter to test the insulation resistance between the heater sheath and the terminal. If the resistance is lower than 0.5MΩ, it means electric leakage. First, check the sealing structure, damage to the sealing end or terminal sealing causes moisture and dust to enter, replace the sealing parts or install a protective junction box. Second, the heater is used in a humid environment for a long time, magnesium oxide insulating powder absorbs moisture and reduces insulation performance. Take out the heater, bake it at 150-200°C for 2-3 hours to remove moisture, and then install it after the insulation resistance returns to normal. Third, the sheath is damaged, and impurities enter the interior, causing insulation failure. In this case, the heater must be replaced immediately to avoid safety accidents.
Slow heating speed and low heating temperature are common faults that affect production efficiency. First, check the power of the heater, insufficient power leads to slow heating, replace with a heater with rated power. Second, poor installation fit, excessive clearance leads to heat loss, reprocess the installation hole to improve fit. Third, the surface of the heater or installation hole is contaminated with dust, oil and impurities, affecting heat transfer, clean the impurities thoroughly. Fourth, the temperature controller is set incorrectly or faulty, check the temperature setting value, and repair or replace the faulty temperature controller. Fifth, the heater is aging, internal components are aged after long-term use, and heating efficiency is reduced, replace with a new heater.
Uneven heating of the cartridge heater leads to uneven temperature of the heated object, affecting product quality. The main reasons are unreasonable heater winding process, uneven heat generation, or unreasonable layout, or loose installation. Replace with a uniform heat type cartridge heater, optimize the layout position and quantity of the heater, ensure firm installation and tight fit. For multi-heater heating systems, check whether each heater is working normally, and replace faulty heaters in time.
In addition to fault-specific solutions, daily preventive maintenance can reduce the occurrence of faults. Regularly check the circuit, terminals and sealing structure of the heater, clean surface impurities, tighten loose parts. Avoid over-temperature and over-power operation, use a precise temperature controller to control the temperature. Store unused heaters in a dry environment to prevent moisture absorption. Choose high-quality cartridge heaters, avoid inferior products, which can reduce the failure rate by more than 60%.
When faults occur, follow the principle of "from easy to difficult" for diagnosis: first check the external circuit and power supply, then check the installation and fit, then test the heater's own parameters, and finally find the root cause. Do not blindly replace heaters without diagnosis, so as not to waste costs and fail to solve the fundamental problem. For complex faults that cannot be diagnosed by yourself, contact professional manufacturers for technical support. Mastering fault diagnosis and solution methods can quickly solve problems, reduce downtime, reduce maintenance costs, and ensure the continuous and stable operation of industrial equipment.
