Information on configuring the zero-angle position for EK8W/AK8H/AK8W/EK9Z/AK8Z/RK8M encoders on the DR2C.. motor

The encoders can be electronically calibrated using a frequency inverter. During the process, the existing zero angle of the encoder is calibrated during assembly and compared to the defined zero angle. The offset is saved. The motor control operates with this saved value.

Alternatively, the RK8M encoder can be mechanically configured in order to match the defined zero angle in its real mounting position. See chapter Additional work for the RK8M encoder on the DR2C.. motorfor additional information

Electronically calibrating the encoder

Note that the motor must be free of loads, the brake must be released, and the rotor must be able to freely rotate.

Using current injection (270° electrical position), the rotor adjusts itself to a certain position.

The current injection is achieved by supplying a direct current positive in phase W and negative in phase V. Phase U is not powered. It may not be powered with more than 80% of the respective motor's nominal current I0.

In this position, the encoder position is subsequently set to 0° by the frequency inverter, or the discrepancy with the defined zero position is saved.

Thus, the offset of the encoder position to the electrical rotor angle of the motor is 270 ° or 4.7 rad.

Observe the following:

  • The motor must be disconnected or disassembled to configure the system or machine’s encoder.
  • Before the configuration process, the "star" or "delta" connection type that is selected for the subsequent control mode of the motor must be wired to the motor. A correct zero position can be determined only if the connection type is identical during the configuration process and operation.
  • The zero angle position set at the factory applies only for the selected "star" or "delta" connection type. If the connection type is changed, the encoder zero angle position must be recalibrated. To do so, use the encoder adjustment function "FCB 18 Rotor position identification" of the SEW-EURODRIVE frequency inverter.

To that end, refer to the operating instructions for the frequency inverter or contact SEW‑EURODRIVE Service.