SS2-t – Safe Stop 2 with time control
When the SS2-t safety subfunction is active, the motor is brought to a standstill electrically. In the idle state, the motor is held in position. The position must be safely monitored after a specified, safety-related time has elapsed (SOS function according to EN 61800‑5‑2). Any movement at standstill triggers the STO safety subfunction. After the STO safety subfunction has been triggered, the idle state has to be ensured, for example, by a mechanical brake.
The SS2-t safety subfunction corresponds to a controlled stop of the drive according to EN 60204‑1, stop category 2.
| = | SS2-t safety subfunction monitored |
| = | STO safety subfunction active |
v | = | Speed |
t | = | Time |
t1 | = | Point in time at which SS2-t is activated and motor deceleration is triggered. |
t2 | = | Point in time at which SOS is activated. |
Δt | = | Safety-related period of time |
INFORMATION
- The SS2-t safety subfunction does not monitor the stopping of the drive.
- The safety-related period of time Δt allows the drive to come to a stop. In the event of a fault, the drive does not come to a stop and only becomes de-energized at the time t2 (STO).
