Installation requirements

NOTICE

The STO wiring must be protected against accidental short circuits or external influences. Otherwise, it may cause the STO input signal to fail.

In addition to the wiring guidelines for the STO circuit, section Electromagnetic compatibility must also be observed.

Shielded twisted-pair cables are always recommended here.

Requirements:

  • The safety-related DC 24 V supply voltage must be EMC-compliant and routed as follows:
    • Outside an electrical installation space, shielded cables must be routed permanently (fixed) and protected against external damage, or other equivalent measures have to be taken.
    • Inside an electrical installation space: Single conductors can be routed.
    • Adhere to the regulations in force for the application.
  • Make sure that you apply shielding for the safety-related DC 24 V supply cable at both ends.
  • Power cables and safety-related control cables must be installed in separate cables.
  • Make sure that no parasitic voltages can be generated in the safety-related control cables.
  • Wiring technology must comply with EN 60204-1.
  • Use only grounded voltage sources with protective extra-low voltage (PELV) according to VDE0100 and EN 60204-1. In case of a single fault, the voltage between the outputs or between any output and grounded parts must not exceed a DC voltage of 60 V.
  • The safety-related DC 24 V supply voltage may not be used for feedback.
  • You can supply power to the 24 V STO input either via an external 24 V supply or via the internal 24 V supply of the inverter. If an external voltage source is used, its cable length to the inverter must not exceed 25 meters.
    • Nominal voltage: DC 24 V
    • STO Logic High: DC 18 – 30 V (Safe Torque Off in standby)
    • Maximum current consumption: 100 mA
  • When planning the installation, observe the technical data of the inverter.
  • Observe the values specified for safety components when designing the safety circuits.
  • Inverters with degree of protection IP20 must be installed in an IP54 control cabinet (minimum requirement) in an environment with degree of pollution 1 or 2.
  • The safe 24 V must be connected between the safety relay and STO+ input in such a way that a fault can be ruled out.
  • The fault assumption "short circuit between any 2 conductors" can be excluded according to EN ISO 13849-2: 2008 under the following conditions.
  • The conductors are:
    • Permanently (fixed) installed and protected against external damage (for example, using a cable duct or armored conduit)
    • Installed in different light plastic-sheathed cables in an electrical installation space provided that both the lines and the installation space meet the relevant requirements, see EN 60204-1.
    • Protected individually by a ground connection.
  • The fault assumption "short circuit between any conductor and an exposed conductive part or ground or a protective conductor" can be excluded under the following condition:
    • Short circuits between a conductor and any exposed conductive part within an installation space.