Frequently asked questions about inverters

In this article, we will learn about the common questions of the inverters which Hao Phuong has summed up!

1. Why after running the command, the Inverter runs but Motor does not run?

The reason may be:

• Frequency runs at 0.
• The motor is broken, the load is too heavy or the machine is mechanically jammed.
• Drive has lost output phase or unbalanced output phase.
• The motor and inverter connecting cable is broken or the contactor (if any) connecting
• the inverter and motor are not closed.
• Controller board defective.

How to fix:

•   Increase the running frequency for the inverter.
•   Fix motor and solve mechanical jam before running again.
•   Check motor cable and inverter.
•   Contact supplier.

2. Why is the motor running so hot when mounting the inverter?

The reason may be:

•   The parameter of the installed motor is not correct
•   Motor wiring is not correct
•   Motor running at too low frequency (below 30 Hz)

How to fix:

•   Look carefully at the motor specification on the label and reset
•   Check that the motor wiring and the inverter voltage supplied to the motor are correct
•   Increase the running frequency of the motor. Can increase the gear ratio …

3. Why does the inverter display normally when powering but the CB close when running?

• Usually, because the output phases of the inverter are short-circuited, double-check and contact your supplier for the best support.
• Check if there is a ground fault, if it is, handles it before running the drive. If the interrupt is occasionally interrupted and the distance between the inverter and motor is quite remote, it is recommended to install an AC-resistance coil at the drive’s output.
• In addition, it may be because the CB has too small rated current, the inverter cable and motor are in phase, ground or motor damage. Please resolve these errors before running again.

4. The inverter running normally for a moment and then stops?

First, check if the “RUN” status light is still on? If turned off, the following causes may occur:

•  Drive command signal is interrupted (control wire is broken or loose wire in control terminal).
• The inverter reports an error, if there is an error, the inverter will stop, display an error and the “Alarm” lamp will light up.

How to fix:

•  Check the control commands wires of the inverter, tighten the control terminals
•  Refer to the error code table to fix
•  Contact the supplier for best support

If the “RUN” light is still on, it may be because:

•  The running speed of the drive is reduced to 0
•  The motor is mechanical or damaged
•  The control board has an error

5. The inverter does not display lights after power on?

The cause of this case may be: The voltage supplied to the inverter does not match, the rectifier bridge is damaged, or it may be due to the capacitor charging resistor and switching power supply damaged. You should check the following:

•  Use a meter to measure the value of the supply voltage to see if it matches the rated voltage of the inverter, otherwise, handle and re-supply accordingly.
•  Check if the “CHARGE” light is on or not, if the lamp is off, it is mostly due to a fault in the rectifier bridge or a charging resistor, but if the light is on, it may be due to a switching power supply problem, contact the supplier level for best support.