Ultra-low temperature freezer power supply and electronic control instrument system description

Ultra-low temperature freezer needs to be tested after a long time of use. What should be paid attention to when the power supply and electronic control instrument system are inspected?

Check the ultra-low temperature freezer power supply and the electronic control instrument system. Before starting the power, check whether the power distribution capacity matches the unit power, and whether the selected cable diameter can withstand the host operating current. Check whether the electrical system is consistent with the unit. The unit is electrically: three-phase five-wire system (three phase lines, one neutral line, one ground line, 380V ± 10%). Check if the power supply line of the compressor is connected tightly. If it is loose, retighten it. The torque at the compressor wiring is 500kg/cm. Due to factors such as long-distance transportation and lifting, the screws may be loose. Failure to do so may result in damage to electrical components (such as air switches, AC contactors, etc.) and compressors in the main control cabinet.

Use a multimeter to carefully check all the electrical circuits of the ultra-low temperature freezer, check that the wiring is properly installed in place; use megaohm measurement to make sure there is no short circuit in the case; check that the ground wire is properly installed in place, and the insulation resistance to ground is greater than 2MΩ; check if the power cable is suitable. Capacity requirements. Check if the disconnect switch is installed on the power supply line of the supply unit. All the wiring of the main circuit in the control cabinet and the external wiring of the control circuit can be energized after comprehensive inspection (such as crankcase oil heater, compressor electronic protector, circulating water temperature sensor, target flow switch wiring, pump connection) Control, etc.); Check if the terminal bolts are tightened and there is no looseness.

The performance of the power supply and the electronic control instrument are more important in the operation of the ultra-low temperature cold box, so regular inspection is recommended.