Siemens SINAMICS S120 System Manual page 188

Drive functions
5.12 Terminals
Power enable inhibit time
If a shutoff valve is connected (p0218.0 = 1), the switch for the shutoff valve remains open
for the power enable inhibit time, i.e. the shutoff valve is closed. This gives the servo
solenoid valve enough time to move to the middle position from the fail-safe position without
pressure. In such cases, the power enable inhibit time must be set to the time required by
the valve to move from the fail-safe to the middle position. If this operation were to take place
under pressure, the drive would move. If no shutoff valve is connected, zero can be entered
as the power enable inhibit time.
The following diagrams show the response when switching on and switching off the 26.5 V
supply for a configuration with and without shutoff valve.
188
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Hydraulic Drive