- Phone：0086-4006769700 / 021-57406070
- Fax：0086-021-57406123
- Email：4006769700@sunny-hvac.com
- Address：No.128 Huian Road Wuqiao Industrial Park Fengxian District Shanghai China
Inspection items before water-cooled screw chiller operation (Part 1)
Inspection of water-cooled screw chiller power supply and electronic control instrument system
1) Before starting the power for the first time, check whether the power distribution capacity matches the unit power, and whether the selected cable diameter can withstand the maximum working current of the host.
2) 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%).
3) Check if the power supply line of the compressor is connected tightly. If it is loose, retighten it. 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.
4) Use a multimeter to carefully inspect all electrical circuits, check that the wiring is properly installed in place; use megaohms 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 5 MΩ; check that the wires meet the capacity requirements. .
5) Check if the disconnect switch is installed on the power supply line of the supply unit.
6) All the wiring of the main circuit in the control cabinet and the external wiring of the control circuit can be energized after checking the wiring diagram; check whether the terminal bolts are tightened and there is no looseness. Check whether the electronic control instruments and electrical appliances are correctly installed, complete and effective, and check whether the wiring inside and outside the electrical control cabinet is clean and free of debris.
7) After checking the above items, power on the control cabinet, the power indicator light is on, observe whether the phase sequence protector is normal, such as the phase sequence protector is normal (green light is on), the single pole switch control loop in the control cabinet is started to work, touch screen (text The display) and the controller are all put into operation.
8) Check whether the external system of the unit meets the starting conditions before starting the machine (for example, the system chilled water pump, cooling water pump, cooling tower fan is external control or host interlocking, if external control needs to be turned on before starting the host.
Inspection of water-cooled screw chiller compressor and refrigerant piping system
1) Check if the oil level in the compressor is normal. The normal compressor oil level is generally in the middle of the sight glass.
2) Check if the coil of the compressor capacitor is locked and the capillary is damaged.
3) All refrigerant valves in the refrigeration system (angle valve at the outlet of the condenser, compressor suction and exhaust shut-off valves) are all open and the refrigerant system is unblocked.
4) Check the high and low pressure values, whether the pressure relay high and low pressure setting values are normal (high pressure setting value is 1.8MPa, low pressure setting value is 0.35MPa).
5) Check if the compressor oil is warmed up for more than 8 hours. At least the oil heater should be energized for 8 hours before the test run to prevent foaming of the frozen oil during start-up. If the ambient temperature is low, the oil heating time needs to be relatively long. When starting at a low temperature, the viscosity of the lubricating oil is large, and it is difficult to start up and the compressor is not properly loaded and unloaded.