Overheating of valve electric actuators is a common fault phenomenon, which may affect equipment performance, shorten service life and even cause safety accidents. The following are the simple causes of fever and the corresponding solutions

I. Common Causes of Fever

1. Motor overload

• Causes: Valve jamming, excessive load (such as valve torque exceeding actuator rated value), transmission component jamming (such as lack of oil in the gearbox).

• Phenomenon: The motor temperature rises sharply, accompanied by an abnormal increase in current.

2. Power supply issue

• Causes: Excessively high or low voltage (deviating from the rated value by more than ±10%), three-phase imbalance (phase-to-phase voltage difference > 5%).

• Phenomenon: The motor operates unstably and the heating is uneven.

3. Poor heat dissipation

• Causes: Poor ventilation at the actuator installation location (such as in a closed cabinet), dust accumulation on the heat sink, and fan failure.

• Phenomenon: The temperature keeps rising after long-term operation.

4. Mechanical friction

• Reasons: Bearing wear, aging of seals, insufficient lubrication (such as low oil level in the gearbox).

• Phenomenon: Local heating (such as at the bearing area), accompanied by abnormal noise during operation.

5. Abnormality in the control circuit

• Causes: Poor contact of relay contacts, aging of circuit board components (such as resistance heating), and interference of control signals.

• Phenomenon: Components inside the control box are overheating, and the actuator operates abnormally.

6. Environmental factors

• Reason: High-temperature environment (> 40℃) and high humidity lead to a decline in insulation performance.

• Phenomenon: Overall heating intensifies, which may be accompanied by the risk of insulation breakdown.

Ii. Solutions

Motor overload handling

• Inspect the valve: Confirm whether the valve is stuck (such as rusted valve stem or medium crystallization). Disassemble, clean or replace the valve if necessary.

• Adjust the load: Check whether the actuator torque matches the valve requirements. Replace the actuator with a larger torque one if necessary.

• Lubricate transmission components: Regularly check the oil level in the gearbox and replenish or replace the grease.

2. Troubleshooting for power supply issues

• Measure voltage: Use a multimeter to detect the input voltage and ensure it is within the rated range (such as AC380V±10%).

• Check the wiring: Tighten the screws of the terminal block, repair damaged cables, and ensure three-phase balance.

3. Improve heat dissipation conditions

• Clean the heat sink: Use compressed air to blow away the accumulated dust on the heat sink. Disassemble and clean it if necessary.

• Check the fan: Make sure the fan is operating normally and replace the damaged one.

• Optimize the installation environment: Avoid installation in confined Spaces. Add ventilation openings or install cooling fans.

4. Reduce mechanical friction

• Replace bearings: Regularly inspect the wear condition of the bearings and replace them if necessary.

• Supplementary lubrication: Add grease regularly as required by the manual (such as once every 6 months).

• Check the seals: Replace aged O-rings or packing to prevent excessive tightness that could increase friction.

5. Repair the control circuit

• Check the relay: Measure the contact resistance, clean the contacts or replace the relay.

• Inspect the circuit board: Use an infrared thermometer to locate the heat-generating components and replace damaged capacitors, resistors, etc.

• Shielding interference: Add signal filters and keep away from strong current line wiring.

6. Respond to environmental factors

• Install temperature control devices: Add cooling fans or air conditioners in high-temperature environments.

• Moisture-proof treatment: Use moisture-proof boxes or apply moisture-proof coatings in damp environments.

Iii. Preventive Measures

• Regular maintenance: Establish a maintenance plan and inspect the motor, gearbox and circuit once every quarter.

• Temperature monitoring: Install temperature sensors to monitor the actuator temperature in real time and set alarm thresholds (such as 70℃).

• Load matching: When selecting the model, ensure that the actuator torque is 1.2 to 1.5 times the valve requirement.

By the above methods, the heating problem of the electric actuator of the valve can be effectively solved, the service life of the equipment can be prolonged, and the safe operation of the system can be ensured. If the problem persists, it is recommended to contact the manufacturer or professional maintenance personnel for further inspection.