Remedies for protection errors

Remedy for over-current

There are various possible causes for an over-current error. Here are several potential ones which would be helpful to check:

  • the controller output results in an exceeding current generated in the phase. Read the Torque actual value and the Target torque during operation, the scope of OBLAC can be used for this purpose. If an exceeding value can be seen in the torque value while the error happens, it often indicates that:

    • the PID controller (of the loop where the error is seen) is tuned too sharp to be stable. In this case, tune the controller softer following our tuning instructions. The controller can be easily unstable if the physical stability of the setup is bad, for example when the setup is not well fixed, or the load is with low rigidity.

    • the command sent to the drive is too sharp. Make sure that your command is sent with an appropriate acceleration / deceleration value. If a position step profile with relatively large amplitude or a quick drag of the slider in Playground-Position is given, this can be the case.

    • if the velocity value doesn’t follow the torque value well (the torque doesn’t lead to active acceleration) there may be a problem in the commutation angle calculation. Check the feedback value of the sensor and perform the offset detection again.

  • an inappropriate power supply is used:

    • a voltage too high or too low would lead to malfunction of components. Check the voltage output of your power supply, if necessary with a measurement tool.

    • if the power output rating of the supply is not enough for the application, the voltage would drop while current is high, leading to the issue declared above.

  • a short in the circuit can easily trigger over-current.

  • a damaged hardware. In this case, there are often visible symptoms such as sparks or smoke.

Remedy for over-voltage

Possible causes for over-voltages include:

  • the voltage output by the power supply is indeed exceeding the threshold. Adjust the voltage output accordingly.

  • the voltage jump during motion leads to the error:

    When a load is causing the motor to turn in the opposite direction of the commanded motion, the motor generates power instead of consuming power. This leads to a voltage jump if there’s no braking chopper in the circuit.

In this case use a power supply with integrated chopper or add a chopper device in the circuit for protection (e.g. Synapticon braking chopper).

Please also refer to our guidelines about regenerative energy.

Remedy for under-voltage

Possible causes for under-voltage include:

  • the voltage supplied to the drive is continuously below the defined threshold.


It is normal to have a small (<1V) drop in voltage in the circuit due to resistance.

The power supply should be set to output a voltage slightly higher than the threshold or the threshold should be set lower in this regard. For better investigation, measure the voltage with a multimeter:

  1. The DC link circuit voltage

  2. The voltage between the main power supply pins on the drive

  3. The voltage output by the power supply

The three results should be close. Otherwise, if there are large difference between the first two results, the hardware may be damaged. If the first two results are close, and the third is different, there may be a big voltage drop in the supply circuit due to factors such as cable resistance.

  • If the error occurs during motion, the voltage output of the power supply drops when the maximum output current is reached. Check the specification of the power supply and make sure that a supply with adequate power rating is used.

Remedy for over-temperature

When the temperature of the drive is too high, it is usually a sign of inadequate cooling. First, please check the values in Core temperature subitem 1: Measured temperature and Drive temperature subitem 1: Measured temperature and note down the values. If the values seem much higher than a reasonable value, please contact Synapticon technical support. Please refer to our thermal installation guide for further information about improving the cooling.