What is the IPM Protection of Air Source Heat Pump?

Air source heat pump IPM protection refers to a fault protection mechanism for intelligent power module (IPM) in air source heat pump system. Its core purpose is to prevent the IPM module from being damaged due to abnormal conditions such as current, temperature, voltage, etc., to ensure safe and stable operation of the system. The following is a detailed explanation:

 

1. The role of IPM module

IPM is the core component of the air source heat pump inverter control system, usually used for:

Driving the compressor motor (adjusting the speed to achieve inverter energy saving);

Controlling the power output of components such as fans and water pumps;

Converting DC power into AC power and accurately adjusting the frequency and voltage.

 

2. Causes of triggering IPM protection

When IPM detects the following abnormalities, it will trigger protection and shut down/reduce frequency:

Overcurrent protection: current exceeds the rated value (such as compressor stall, short circuit, load mutation);

Overheat protection: module temperature is too high (poor heat dissipation, high ambient temperature);

Overvoltage/undervoltage protection: DC bus voltage abnormality (power supply fluctuation, capacitor failure);

Short circuit protection: output short circuit or ground fault;

Drive signal abnormality: control circuit failure (such as PWM signal loss).

 

3. Performance of IPM protection

The equipment suddenly shuts down, and the control panel displays a fault code (such as "E5", "IPM fault");

The system cannot start, or frequently trips during operation;

Accompanied by abnormal noise (such as current sound, relay beating sound).

 

4. Common solutions

Triggering causes and troubleshooting steps

1. Overcurrent

Check whether the compressor is stuck or the load is too large; measure whether the motor winding is short-circuited or grounded.

2. Overheating

Clean the dust on the radiator and check whether the fan is running normally; ensure that the ambient temperature does not exceed the IPM working range (usually ≤50℃).

3. Abnormal voltage

Check whether the input power supply voltage is stable (such as 380V±10%); check whether the DC bus capacitor is aging.

4. Short circuit fault

Disconnect the load and use a multimeter to measure the ground/phase resistance of the IPM output terminal to check for line or motor short circuit problems.

5. Control signal problem

Check whether the power supply of the driver board is normal and whether the PWM signal line has poor contact; replace the faulty driver chip or control board.

 

5. Precautions

Regular maintenance: clean the heat sink and check the fan operation;

Stable power supply: install a voltage stabilizer or surge protector;

Avoid overload: use the equipment according to the rated power and do not overload for a long time;

Professional maintenance: non-technical personnel should not disassemble the IPM module by themselves (high voltage danger).

 

6. Precautions

Damage to the IPM module may cause the whole machine to be paralyzed and needs to be replaced by professionals;

Some faults may be caused by peripheral circuits (such as sensors and capacitors), which need to be fully checked;

The protection logic and fault codes of different brands of equipment may be different, and specific instructions need to be referred to.

 

Summary

IPM protection is a key safety mechanism for air source heat pumps, which is designed to prevent power modules from being damaged due to electrical or temperature abnormalities. When encountering such faults, it is necessary to combine the system operation status and detection tools to gradually check, and contact professional maintenance personnel for processing if necessary.