How to detect potential problems?
1. Stop operation and check the power supply of the air electric heater to ensure whether the problem is caused by the circuit. Check if the three-phase power is normal or if there is a phase loss. If there is a phase loss, promptly ask an electrician to repair it. Check if the fuse is intact and if the equipment itself is burned out. Open the air electric heater protective cover and use a multimeter to check if any single heating element is open circuit.
2. Abnormal temperature display. When the temperature data of the air electric heater is abnormal, we first need to check if the air switch is closed, and then check if the control circuit is intact. After powering on, if the heater temperature cannot rise properly, we need to troubleshoot the cause. First, check if the fuse is intact. If there is no problem, check if the heater itself is damaged. In winter when temperatures often drop below 0°C, if no preventive measures are taken, the water in the heater can easily freeze, affecting normal operation and possibly causing pipe bursts. The reasons for freezing of surface coolers may vary by region. In milder climates, it may be because there is no preheat coil in winter and there is water in the surface cooler. After inhaling cold outdoor air, freezing occurs.
At this time, attention should be paid to draining the water from the surface cooler when not in use in winter. For example, in the south, freezing of the surface cooler in winter may be caused by extremely low temperatures on a certain day, where the return air is not well mixed with fresh air, causing outdoor cold air to blow directly onto the surface cooler. We can install a mixing valve to fully mix fresh air with return air. The air electric heater body consists of multiple tubular heating elements, a shell, a protective cover, a base, and other components. The heating element is a tubular electric heating element made of high-temperature resistance alloy wire, with a stainless steel tube as the protective sleeve, filled with crystalline magnesium oxide, and formed by compression process. It has the characteristics of high mechanical strength, high thermal efficiency, wear resistance, and corrosion resistance. A guide baffle is installed inside the shell to ensure uniform heating during air circulation. The working principle of the control cabinet is to use an intelligent digital temperature controller, high-power thyristor, and thermal resistance to form a measurement, regulation, and control circuit. The thermal resistance converts the heater outlet temperature into a milliampere signal, which is sent to the intelligent digital temperature controller for amplification and comparison, then displays the corresponding temperature value. When the displayed value is higher than the set value, the thyristor does not conduct. When the displayed value is lower than the set value, the intelligent digital temperature controller triggers the thyristor to conduct. When the displayed value is close to the set value (i.e., near the set value), the intelligent digital temperature controller changes according to P, I, D rules, giving the control cabinet good control accuracy and regulation performance. The intelligent digital temperature controller automatically changes the number of trigger pulses of the thyristor based on the milliampere signal from the thermal resistance, i.e., controls the conduction angle of the thyristor per unit time, adjusts the voltage, controls the heating power of the heating element, ensuring energy saving and constant temperature, avoiding current surges, and extending service life. When the equipment is suddenly shut down and then restarted, the control cabinet can automatically adjust smoothly.
