Solution of err2 fault (output phase failure) is reported during frequency inverter’s operation

Fault Name:

Err2 fault (output phase failure) is reported during frequency inverter’s operation.

Fault explanation:

Err2 is the fault reported by the frequency inverter when the output current is not balanced.

Fault Symptom: 

The frequency inverter reports Err2 fault every time after it’s just started then it cannot be used.

Causes:

On-site reasons or the frequency inverter reasons itself

Solutions:

Faults caused by on-site reasons can be solved by troubleshooting

If Err2 is reported due to device damage, then replace them.

Analysis:

Communicate with the customer to determine if Err2 failure is caused by the on-site reason:

Let the customer remove the motor wiring, run the frequency inverter to the set frequency and measure whether the output voltages are balanced. If the output voltages are all normal, the Err2 fault may be caused by on-site causes, instruct the customer to solve the on-site cause from the following aspects:

Open the motor terminal box to check whether the motor wirings are fixed well and whether the wiring heads are burnt out. If they are, instruct the customer to cut out the burned part and re-fix the connection to eliminate the Err2 fault.

Note:

1. Through analysis, the causes of the above failures are as follows: a. they aren’t fixed well b. The pressure line is not pressed well, the wire leaks and the pressure sheets are so few, resulting in insufficient over-current, long-term overheating leads to burning.

2. Measure the resistance between U, V and W phases with a multimeter. If the resistance difference between any two of them is relatively large, then the three-phase current is seriously unbalanced, so it reports Err2.

3. Inspect the leads from the frequency inverter output to the motor side for signs of skin breakage, aging, breakage, etc. If it has, instruct the customer to replace the wire and re-power on the test machine.

The damage of the frequency inverter itself causes it to report Err2 fault. The specific phenomena are as follows:
1. Disconnect the motor cable and use a multimeter to test the U, V, and W output of the frequency inverter. If the measured output voltage has a large deviation, then you could eliminate the cause of on-site.

Note:

Confirm whether the multimeter used by the customer can accurately measure the output voltage of the frequency inverter. Fluke's multimeter, clamp meter, mechanical meter and pointer table can all correctly test the output voltage of the frequency inverter. Test when the frequency inverter operates stably at the highest frequency:

If the customer chose vector mode, it is better to change to V/F mode before measure.

When the frequency inverter is completely powered off, adjust the multimeter gear to the diode mode, connect the black terminal to the DC+ terminal of the frequency inverter, the red lead to U, V, and W, and then connect the red to the DC-, black to UVW respectively, to determine if there is a diode voltage drop. If not, it is determined that the frequency inverter module is damaged.

If the measured output voltage of the frequency inverter is normal, the Err2 fault may be caused by damage of the current sensor, power supply board, or current detection loop device on the control board.