Siemens SINAMICS S120 System Manual page 191

Power enable
● The power enable command (corresponding to pulse enable for an electrical drive) can
be issued and/or canceled via the following paths:
● Control word (from NC)
● Faults
The manipulated variable inhibit time (p0230) starts after controlling the shutoff valve
(opening the valve) or after switching on the power supply
Switching off the shutoff valve supply
If a shutoff valve has been parameterized (p0218.1 = 1), and if the power supply voltage of
the servo solenoid valve for a power inhibit is to be switched off (p0218.1 = 1), then the
manipulated variable inhibit time (p0230) is the time that the system should wait until the
power supply for the servo solenoid valve is disconnected. The shutoff valve can be closed
during this period.
Actions for power enable (external 26.5 V power supply available, control has been
enabled):
● The 26.5 V power supply for the servo solenoid valve is switched on immediately (if it has
not already been switched on).
● If the 26.5 V power supply for the servo solenoid valve was available, then the 26.5 V
power supply for the shutoff valve is immediately switched on, otherwise the 26.5 V
power supply for the shutoff valve is switched on after the power enable inhibit time.
● After the 26.5 V power supply for the shutoff valve has been switched on, during the
manipulated variable inhibit time, a velocity setpoint "= 0" is maintained.
Actions for a power inhibit
● The 26.5 V power supply for the shutoff valve is switched off immediately, if p218.0=1
(the shutoff valve closes).
● If p0218.1 = 1, the 26.5 V supply for the servo solenoid valve is also switched off when
the manipulated variable inhibit time (p0230) expires (the servo solenoid valve moves to
the fail-safe position).
● If p0218.1 = 0, the 26.5 V power supply for the servo solenoid valve is switched on.
● If p0218.0 = 0 and p0218.1 = 1 (no shutoff valve), then the 26.5 V power supply for the
servo solenoid valve is switched off immediately (servo solenoid valve moves to the fail-
safe position).
● A valve setpoint = 0 V is output.
● I components of the controller are deleted.
● Valve spool monitoring is deactivated.
● If a central shutoff valve is installed, it is the responsibility of the user to appropriately
interlock the signals (e.g. using the PLC) such that the central shutoff valve is actuated
when the power is inhibited.
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Drive functions
5.12 Terminals
191