Commissioning, Start-up and Shutdown Procedures

1. Connect the power supply cable and earth wire. Verify the main voltage is correct and confirm the three-phase power supply is correct.
2. Verify the oil level in the oil-gas tank is above the upper mark to ensure it remains between the upper and lower marks during normal operation.
3. Prior to trial operation, add approximately 0.5 litres of lubricating oil through the inlet valve. Manually rotate the air compressor several times to prevent oil starvation and potential burnout during start-up. Exercise particular caution to prevent foreign objects entering the compression chamber, which could damage the compressor head.
4. Inspect the cooling system.
5. Verify the exhaust piping is unobstructed to prevent rapid pressure buildup causing back pressure after startup.
6. Within 2 seconds of pressing the start button, immediately press the emergency stop button. Check whether the rotation direction matches the arrow on the compressor head end face (shaft extension end). If the rotation is incorrect, swap any two of the three power supply wires.
7. Press the start button to commence operation.
8. Observe whether gauges and indicator lights function normally, paying attention to any abnormal indications from alarm lights.
9. Should abnormal noises, vibrations, or oil leaks occur, immediately press the ‘Emergency Stop’ button to halt operation for inspection.
10. Verify that the discharge temperature (as indicated by the discharge temperature gauge) remains between 75–95°C.
11. When shutting down, press the stop button. The relief valve will immediately discharge air automatically. After a delay of 10–15 seconds, the motor will cease operation. This design prevents the air compressor from stopping abruptly under heavy load conditions.

Pre-Startup Checks

These checks are essential to ensure proper operation and extend the compressor’s service life.

1. Open the drain valve at the bottom of the oil-gas separator to discharge condensation accumulated during shutdown. Close the valve immediately once oil begins to flow.
2. For compressors operating in high-temperature environments or running continuously for 24 hours, ensure at least one shutdown period of 10 hours or more per week. Following this, perform step 1 and adjust the discharge temperature to between 75–95°C. This primarily prevents oil emulsification, bearing damage in the compressor head, and reduced service life of the oil-fine separator.
3. Open the rear cooler drain valve to discharge condensate.
4. Verify the oil level is normal. Lubricant quantity should be adequate; replenish if insufficient. Mixing lubricants of different grades is strictly prohibited. Using non-standard or non-manufacturer-specified lubricants may cause severe damage, including compressor head seizure. When topping up lubricant, ensure the system is depressurised before opening the filler cap.
5. Observe the oil level only after the machine has been shut down for 10 minutes. By this time, circulating oil in the system will have largely returned to the oil-gas separator. The oil level during operation may be slightly lower than when the machine is stopped.

Precautions During Operation

1. Immediately shut down the machine if abnormal noises or vibrations occur during operation.
2. Pipework and vessels remain pressurised during operation. Do not loosen pipes, plugs, or open unnecessary valves.
3. If oil level cannot be observed through the sight glass during prolonged operation, shut down immediately. After ten minutes, check the oil level. If insufficient, replenish to a position slightly above the upper mark once system pressure has dropped to zero. This ensures the oil level remains between the upper and lower marks during normal operation.
4. Condensate will accumulate in the rear cooler. The drain valve should be slightly opened or an automatic drain valve fitted; otherwise, moisture will be drawn into the system.
5. During operation, inspect instruments every two hours and record voltage, current, air pressure, discharge temperature, oil level, etc., for future maintenance reference.

Procedures for Extended Shutdown

During prolonged shutdowns, strictly adhere to the following procedures, particularly in regions or seasons where temperatures fall below 0°C or humidity is high.

1. Shutdown exceeding three weeks

• Wrap electrical equipment such as motor control panels in plastic sheeting or oil paper to prevent moisture ingress.
• Drain all water from oil coolers and aftercoolers to avoid freezing damage.
• Rectify any faults prior to shutdown to facilitate future operation.
• Drain condensate from oil-gas separators, oil coolers, and aftercoolers after two to three days.

2. Shutdown exceeding two months In addition to the above procedures, implement the following:

• Seal all openings to prevent ingress of moisture and dust.
• Wrap safety valves, control panels, and similar components in oil paper or equivalent to prevent corrosion.
• Replace lubricating oil prior to shutdown and run the unit for 30 minutes. Drain condensate from the oil-gas separator and oil cooler after two to three days.
• Drain all cooling water completely.
• Where possible, relocate the unit to a dust-free, dry environment for storage.

3. Restart Procedure

• Remove all plastic or oil paper from the air compressor.
• Measure the motor’s insulation resistance, which should exceed 1MΩ.
• Follow the remaining steps as outlined in the trial run procedure.