What is the reason why the air compressor cannot be started after being stopped for a while

The air compressor cannot be started after being out of service for a period of time, which may involve various reasons such as electrical system, mechanical structure, control logic and environmental factors. The following is the systematic investigation process and solutions:

1. Troubleshooting electrical system faults

1. Power supply verification
   • Use a multimeter to check whether the three-phase voltages are balanced (the error should be <5%)
   • Check whether the circuit breaker and fuse trip or blow
   • Make sure the power phase sequence is correct to avoid triggering of reversal protection
2. Motor drive testing
   • Measure the insulation resistance of motor windings (should be>1MΩ)
   • Check the starting capacitor capacity (error should be <±10%)
   • Verify drive parameter settings (especially sleep wake-up function)
3. control loop diagnostic
   • Check whether the emergency stop button is reset
   • Verify PLC input and output point status
   • Test pressure sensor and temperature sensor signal feedback

2. Removal of mechanical system blockages

1. Transmission mechanism inspection
   • Manual turning test main machine resistance (should be <30N·m)
   • Check whether the coupling elastomer is aging and cracking
   • Verify belt tension (deflection should be 15-20mm)
2. Lubrication system evaluation
   • Observe the oil level mirror to confirm the amount of oil (it should be in the green area)
   • Take samples and test the viscosity of the lubricating oil (85-95mm²/s at 40℃)
   • Check whether the oil circuit stop valve is open
3. Compression component inspection
   • Remove the intake valve and check the tightness of the valve plate
   • Use an endoscope to check the rotor clearance of the main machine (should be>0.15mm)
   • Test the minimum pressure valve opening pressure (error should be <±5%)

3. Reset the control system

1. Parameter reset process
   • Perform the controller “Factory Reset” operation
   • Reset key parameters such as loading pressure and unloading pressure
   • Calibration timing maintenance reminder (such as clearing oil filter timing)
2. Protection function removed
   • Reset high temperature protection (need to be cooled to below 80℃)
   • Remove phase sequence protection (adjust any two-phase wiring)
   • Bypass pressure sensor test initiated

4. Response to environmental factors

1. Low temperature environmental treatment
   • Install the oil heating belt (set to 20℃ to automatically start)
   • Use low-temperature lubricants (pour point should be <-15℃)
   • Increase pre-lubrication time (recommended for 10 minutes without load)
2. Moisture protection
   • Dehumidification of electrical cabinets with desiccant
   • Check the insulation performance of the terminal (should be>50MΩ)
   • Replace damp PCB boards

5. Preventive maintenance recommendations

1. Long-term shutdown preparation
   • Drain condensed water in the oil and gas cylinder
   • Close all stop valves to prevent corrosion
   • 30 minutes of no-load operation every month
2. Pre-launch checklist
   • Make sure the safety valve is within the verification validity period
   • Check the torque of all fasteners (focus on checking the fixing bolts of the main engine)
   • Verify ground resistance (should be <4Ω)

Through the above-mentioned step-by-step investigation, more than 90% of shutdown and restart failures can be located. If all tests are completed and still cannot be started, it is recommended to contact professional maintenance personnel to use vibration analyzers, infrared thermal cameras and other equipment for in-depth testing. Equipment health files should be established daily to record operating parameters before each shutdown to provide data support for fault analysis.