F.A.Q.

A. External cause:

1. Electric machinery is overloaded suddenly, to cause the shock wave much larger to over current.

2. Electric machinery and electric cables of their isolations have damaged, to cause circuit short to over current.

3. Cause of over current is related to leakage impedance and coupling impedance. Therefore, electric machinery and electric cables have to fit in with their standards.

4. The power output of an AC Motor Drive needs to come with the power factor capacitor or wave absorber.

5. As AC Motor Drive has installed Speed Coder, of which speed feedback signal is lost or abnormal will cause the AC Motor Drive to over current. Please check the coder and its cables. 

B. AC Motor Drive cause:

1. Parameter settings.

For example, shorter accelerated time, between proportion and integration in PID is not match or set too high, to cause the power output current of an AC Motor Drive to oscillate.

2. AC Motor Drive hardware:

a) Mutual induction is damaged. If an AC Motor Drive is not started up yet but its main circuit is conducting electricity, we can know mutual induction damaged.

b) Main circuit board or the channels of voltage detector damaged may happen to over current.

<Cause of damage to PCB >

1) Electric conductor sticks on the PCB or corrosiveness air rusting PCB will bring static electricity to damage.

2) Zero potential on the PCB linking up machine box will bring electric arc to damage.

3) Bad connection with ground system or interference with PCB will bring to damage.

c) Cause of linked components is not fixed. For example, bad connection with feedback signals will happen to over current.

d) When Load is not stable, we suggest using DTC mode. Because control speed in DTC is very fast. it can produce actual figure of accurate torque and magnetism on alternate 25 microsecond. Auto tuning can adjust PID parameter automatically to stabilize output current in an AC Motor Drive.