Cable Types And Lengths; Grounding Of Protective Shields - ABB ACQ580-34 Hardware Manual

142 The Safe torque off function
• A CPTC-02 thermistor protection module can also be used. For more information, see
the module documentation.
￭

Cable types and lengths

• Double-shielded twisted-pair cable is recommended.
• Maximum cable lengths:
• 300 m (1000 ft) between activation switch [K] and drive control unit
• 60 m (200 ft) between multiple drives or inverter units
• 60 m (200 ft) between external power supply and first control unit
Note: A short-circuit in the wiring between the switch and an STO terminal causes a
dangerous fault. Therefore, it is recommended to use a safety relay (including wiring
diagnostics) or a wiring method (shield grounding, channel separation) which reduces or
eliminates the risk caused by the short-circuit.
Note: The voltage at the STO input terminals of the drive must be at least 13 V DC to be
interpreted as "1".
The pulse tolerance of the input channels is 1 ms.
￭

Grounding of protective shields

• Ground the shield in the cabling between the activation switch and the control unit at
the control unit only.
• Ground the shield in the cabling between two control units at one control unit only.