Safety subfunctions

The following drive-related safety functions can be used:

• STO (Safe Torque Off in accordance with IEC 61800-5-2) by disconnecting the STO input.
• If the STO function is activated, the frequency inverter no longer supplies power to the motor for generating torque. This safety subfunction corresponds to a non-controlled stop according to EN 60204‑1, stop category 0.
• The STO input must be disabled by a suitable external safety controller/safety relay.
• The following figure shows the STO function:

v	=	Speed
t	=	Time
t1	=	Time at which STO is triggered
	=	Disconnection range

• SS1-t (SS1(c)) (Safe stop 1 with time control according to IEC 61800-5-2) by means of suitable external control (e.g. safety relay with delayed disconnection).
• The following procedure must followed:
• Decelerate the drive via the setpoint input using a suitable braking ramp.
• Disconnect the STO input (thereby 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 following figure illustrates the SS1-t function:

v	=	Speed
t	=	Time
t1	=	Time at which the braking ramp is initiated
t2	=	Time at which STO is triggered
Δt	=	Delay time until STO is triggered
	=	Range of safe time delay
	=	Disconnection range