Encoder cable requirements

  • Use a shielded encoder cable. Connect the shield at both ends.
  • Max. length of the encoder cable: 100 m
  • Use the prefabricated encoder cables from SEW-EURODRIVE. Observe the following requirements if you use other encoder cables:
    • Encoder cable length ≤ 50 m
    • The cross section of each core of the encoder cable must be ≥ 0.25 mm2. The resistance load per unit length of the cores must not exceed 78 Ω/km (at 20 °C).
    • Encoder cable length > 50 m:
    • The cross section of the cores for the encoder voltage supply and GND must be ≥ 0.5 mm2. The resistance load per unit length of these cores must not exceed 39 Ω/km. The resistance load per unit length of the signal cores must not exceed 78 Ω/km (at 20 °C).
    • The encoder cable may have the following maximum capacitances per unit length:
    • Capacitance per unit length core/core: CA’ = 70 pF/m
    • Capacitance per unit length core/shield: CS’ = 120 pF/m
    • In the signal path from the encoder to the inverter, the encoder signals must not branch off to other devices.

The encoder cable may not conduct any signals other than the encoder signals, i.e. the encoder signals must not be conducted with other signals in the same cable. The cores of encoder signals must be in twisted pairs as follows:

  • UB and GND
  • A+ and A-
  • B+ and B-