Emergency shutdown operation of the air pump under overload conditions

The emergency shutdown operation of the air pump under overload conditions must follow safety regulations. Measures such as cutting off the power supply, closing the valve, and system pressure relief should be taken to prevent equipment damage. At the same time, protective devices should be equipped and fault information should be recorded. The following are the specific contents:

Cut off the power supply immediately

When the air pump is overloaded, the emergency stop button should be pressed first or the control power supply should be directly cut off to quickly stop the motor operation. This operation can prevent the motor windings from overheating, insulation damage or electrical fire caused by continuous overload. For instance, when the current of the air pump exceeds the rated value by more than 10% and persists for 30 seconds, immediate power-off is required.

2. Close the inlet and outlet valves

After cutting off the power supply, the intake valve and exhaust valve of the air pump should be closed quickly to block the flow of the medium. This step can prevent abnormal increase in system pressure from causing pipeline rupture, or avoid the backflow of the medium from causing the air pump to reverse. For instance, if the valve of an air pump that conveys high-pressure gas is not closed in time, the impeller may fall off due to the reaction force.

3. System pressure relief and exhaust

Release the residual pressure in the system by opening the vent valve or safety valve. Ensure that the pressure gauge returns to zero before proceeding with subsequent operations. If the pressure in the gas storage tank exceeds the design value (such as 1.2 times the rated pressure), the pressure relief program should be initiated first. Direct maintenance without pressure relief may lead to the risk of container explosion.

4. Troubleshooting and record-keeping

Check the causes of overload and focus on the following items:

Electrical system: Measure the insulation resistance of the motor (normally it should be ≥0.5MΩ), and check whether the three-phase current is balanced (deviation ≤5%).

Mechanical components: Confirm the bearing temperature (≤75℃) and the alignment of the coupling (radial deviation ≤0.05mm);

Process parameters: Verify whether the actual working pressure exceeds the value indicated on the nameplate (such as 1.1 times the rated pressure).

Record data such as the time of fault occurrence, ambient temperature, and load conditions to provide a basis for subsequent maintenance.

5. Suggestions for the configuration of protective devices

Overload protector: Thermal relays or electronic protectors are selected. The action time is set to trip within 10 to 20 seconds when 1.1 times the rated current.

Pressure switch: An electrical contact pressure gauge is set at the exhaust port. When the pressure is ≥1.1 times the set value, the power supply is automatically cut off.

Temperature sensor: PT100 probes are installed at the motor winding and bearing positions to achieve over-temperature alarm (85℃) and shutdown linkage.