SS1-t (safe stop 1 with time control according to EN 61800-5-2)

  • SS1-t (safe stop 1 with time control according to EN 61800-5‑2) by means of suitable control (e.g. safety relay delayed disconnection).
  • The following sequence is mandatory:
    • Decelerate the drive using an appropriate deceleration ramp specified via setpoints.
    • Disconnect the STO input (= triggering the STO function) after a specified safety-related time delay.
  • This safety subfunction corresponds to a controlled stop according to EN 60204‑1, stop category 1. The SS1-t function corresponds to the former presentation of the SS1(c) function.
  • The following figure illustrates the SS1‑t function:

v

Velocity

t

Time

t1

Point of time when brake ramp is initiated

t2

Point of time when STO is triggered

Δt

Delay time until STO is triggered

Safe time delay range

Disconnection range