1- Influence of insulation resistance
The heating conductor of the electric heater is generally selected by the resistance wire to generate heat, and the electrical effect is converted into the thermal effect, so the insulation performance of the electric heater should be kept in good condition. If the electric heater is not used for a long time or used for the first time, use a shaker to measure the insulation resistance to see if it reaches the specified value. When the insulation resistance is too low, it must be dried and preheated until it reaches the specified value, otherwise it is prohibited to use .
2- Effect of equipment harmonics
The sources of harmonics in the power grid are transformers, frequency converters, thyristor equipment, etc., and the power supply system of the electric heater includes transformers, thyristor temperature control equipment, etc. The thyristor temperature control device even in an ideal state, the three-phase power supply is completely symmetrical, when the DC converter reactance is equal to zero, the transformer will also flow through the square wave twice, the primary side flows through the trapezoidal wave, and its current waveform will also be distorted. In reality, it is difficult for a three-phase AC power supply system to be completely symmetrical, so harmonic components become more complicated, current and voltage waveform distortion becomes more serious, and harmonics cause harm to electric heater equipment. Harmonics of the 3rd, 5th and 7th harmonics of the electrical system are the most serious and have the greatest impact on the equipment, which makes the heater run unevenly, the heating is unstable, the temperature fluctuates, and it is difficult to ensure the stable operation of production.
3- Influence of electric heating temperature controller
Electric heating temperature controller is a kind of thermostat, mainly used to automatically adjust the temperature of electric heater. Intuitive, durable and easy to operate. When the temperature controller is connected to the power supply, you can toggle the power switch of the temperature controller, the temperature controller is turned on, and then the POWER indicator light of the POWER is turned on. Use the temperature controller to set the temperature of the electric heater. The user sets the temperature of the electric heater according to his own needs, and the temperature control accuracy depends on the temperature controller product. If the temperature of the electric heater is lower than the set temperature, the relay contact in the temperature controller is closed, and the electric heater starts to drive. And the heating indicator light will be on. If the actual temperature of the electric heater matches the temperature set by the thermostat, the relay contact of the temperature controller will be opened at this time, and the originally lit indicator light will be dimmed, and the internal temperature controller There is high temperature protection temperature control to prevent the electric heater from damaging the equipment. The thermostat plays a very important role in the automatic control of the electric heater. Once its internal contact or control board is damaged, it will affect the normal operation of the electric heater