Today, let's know what necessary inspections should be done before the next screw chiller is started?
1： Inspection of power supply and electric control instrument system
Before the first startup, check whether the distribution capacity is consistent with the unit power, and whether the selected cable diameter can withstand the maximum working current of the host.
1. Check whether the electrical switch is consistent with the unit. The electrical system of the unit is three-phase five wire system (three phase lines, one neutral line, one ground wire, 380V ± 10%).
2. Check whether the power supply line of the compressor is well connected. If it is loose, retighten it. The tightening torque at the compressor connection is 500kg.cm. The screws may become loose due to the long distance transportation and hoisting of the main engine. Otherwise, the electrical components (such as air switch, AC contactor, etc.) in the host control cabinet and the compressor may be damaged.
3. Carefully check all electrical circuits with a multimeter to see if the wiring is correctly installed; Measure with megohm and make sure there is no short circuit in the shell; Check whether the grounding wire is correctly installed and the insulation resistance to the ground is greater than 2M Ω; Check whether the power cord meets the capacity requirements.
4. Check whether the power line supplied to the unit is installed with a circuit breaker.
5. All the wiring of the main circuit in the control cabinet and the external wiring of the control circuit shall be fully checked against the wiring diagram before being energized (such as the wiring of crankcase oil heater, compressor electronic protector, circulating water temperature sensor, target flow switch, joint control of water pump, etc.); Check whether the terminal bolts are tightened without looseness. Check whether the electric control instruments and appliances are installed correctly, completely and effectively, and whether the inside and outside of the electric control cabinet, especially the wiring ports at each point, are clean and free of debris.
6. After checking the above items, when the control cabinet is powered on, the power indicator will light up. At this time, the oil heater starts to work, and observe whether the phase sequence protector is normal. If the phase sequence protector is normal (the green light is on), close the single pole switch (QF2) in the control cabinet and the control circuit will start to work, and the touch screen (text display) and PLC controller will all be put into operation.
You are welcome to pay attention to the official website of Amy High Refrigeration. We will continuously update you with some knowledge about the chiller industry.