If the cold storage compressor does not start, it is mostly due to a fault in the motor and electrical control. During maintenance, it is necessary to check not only various electrical control components, but also the power supply and connecting lines.
①Power supply line failure fault analysis: If the compressor does not start, generally check the power line first, such as the power fuse is blown or the wiring is loose, the disconnection causes a phase loss, or the power supply voltage is too low, etc. Troubleshooting method: When the power supply phase is missing The motor makes a “buzzing” sound but does not start. After a while, the thermal relay activates and the contacts jump open. You can use a multimeter’s AC voltage scale to check whether the fuse is blown or measure the voltage of the image. If the fuse is blown, replace it with a fuse of appropriate capacity.
② Temperature controller failure analysis: Refrigerant leakage in the thermostat temperature sensing package or thermostat failure causes the contact to be normally open.
Troubleshooting method: Turn the thermostat knob to see if the compressor can start in the * temperature range (digital * or forced cooling continuous operation level). If it cannot start, further observe whether the refrigerant in the temperature sensing bag is leaking or touching. Check whether the point action fails, etc. If it is minor, it can be repaired. If it is serious, it should be replaced with a new thermostat of the same model and specification.
③ Analysis of motor burnout or short circuit between turns: When the motor windings are burned out or short circuit between turns, the fuse will often blow repeatedly, especially when the blade switch is pushed up. For open-type compressors, at this time You can smell the smell of burnt enameled wire coming from the motor.
Troubleshooting method: Use a multimeter to check whether the motor terminals and the shell are short-circuited, and measure the resistance value of each phase. If there is a short-circuit or a certain phase resistance is small, it means that the winding turns are short-circuited and the insulation is burned. During inspection, you can also use the insulation resistance meter to measure the insulation resistance. If the resistance is close to zero, it means that the insulation layer has been broken down. If the motor is burned out, the motor can be replaced.
④Fault analysis of pressure controller: When the pressure value of the pressure controller is improperly adjusted or the spring and other components in the pressure controller fail, the pressure controller operates within the normal pressure range, the normally closed contact is disconnected, and the compressor Unable to start.
Troubleshooting method: You can disassemble the box cover to see if the contacts can be closed, or use a multimeter to test whether there is continuity. If the compressor still cannot start after manual reset, you should further check whether the system pressure is too high or too low. If the pressure is normal and the pressure controller trips again, you should readjust the high and low pressure control ranges of the pressure controller or replace the pressure control. device.
⑤ Failure analysis of AC contactor or intermediate relay: Generally, contacts are prone to overheating, burning, wear, etc., resulting in poor contact.
Troubleshooting method: Remove and repair or replace.
⑥Thermal relay failure fault analysis: The thermal relay contacts tripped or the heating resistance wire burned out.
Troubleshooting method: When the thermal relay contacts trip, first check whether the set current is appropriate and press the manual reset button. If the compressor does not trip after starting, the cause of the overcurrent should be found out and repaired before restarting. Press the reset button. When the heating resistor wire burns out, the thermal relay should be replaced.
Guangxi Cooler Refrigeration Equipment Co.,L td.
Tel/Whatsapp:+8613367611012
Email:karen@coolerfreezerunit.com
Post time: Apr-22-2024