The 6SE70 inverter reports fault code F002, which means: The bus undervoltage. There are the following reasons:

1). The fuse is usually burned. External to the fuse device, also inside the device. A multimeter can be used to figure out which burned. Don't charge for insurance when changing newspapers, it is dangerous, and easy to burn internal insurance. And to check the reason for good insurance can be replaced. The main reasons are several, the motor does not match, cable to the ground, bad bus contact.

2). Inverter display voltage is low, see R006 display voltage, voltage difference is too much, there are several reasons:

There are N resistors in the detection circuit near the fuse, and the role is to reduce the voltage ratio. If there is burned, the voltage display will become low, and the more the bad resistance, the lower the display voltage is.

3) The CUVC board is broken.

4). The bus voltage P071 calibration value is too high, parameter P071 = device input voltage.

The above points can help solve the problem of F002 quickly.

P071 = device input voltage F002 is pre-charge fault


If the minimum DC bus voltage (P071 line voltage x 1.34) is less than 80% in the maximum precharge time of 3 seconds, the fault F002 is reported.

If the value of your P071 is set to 380V, then the failure threshold of F002 is: 380X1.34X80%=407.36V

For F002 pre-charge faults, there are several possible causes -

1. There may be a problem with the charging capacitor.

2. There may be a problem detecting the pre-charge voltage circuit.

3. If the inverter is stored for more than one year, it must be pre-charged before use, otherwise it will burn the circuit board or alarm.

4. Check if there is any problem with the incoming line voltage. Whether the power supply voltage is too low or the power supply is missing phase.

5. Check if the setting of parameter P071 is correct.

6, if the above are normal, check the inverter's rectifier unit -

1) The rectifier unit must be put into the grid before the inverter;

2) whether the parameter setting of the rectifier unit is correct;

3) Is there any problem in the hardware of the rectifier unit, such as the fuse burned and so on.