Safe Torque Off (Sto) - Lenze i550 Commissioning Manual

Safety functions

Safe Torque Off (STO)

15.1 Safe Torque Off (STO)
The motor cannot generate torque and movements of the drive.
DANGER!
Automatic restart if the request of the safety function is deactivated.
Possible consequences: Death or severe injuries
▶ You must provide external measures according to EN ISO 13849−1 which ensure that the
drive only restarts after a confirmation.
DANGER!
The power supply is not safely disconnected.
Death or serious injury due to electrical voltage.
▶ Turn off the power supply.
Preconditions
Inverter with I5MASA000 safety module
Details
Safe disconnection of the drive
1. A safety sensor requests the safety function.
2. The pulse width modulation is safely switched off by the safety unit.
The inverter switches to the STO active device status (0x6041, Bit15 = 0).
The power drivers do not generate a rotating field anymore.
The motor is safely switched to torqueless operation (STO).
The functional principle depicted applies to Basic Safety (STO) and Extended
Safety. The terminals shown apply to Basic Safety.
Fig. 4: Functional principle of safety technology for Extended Safety and Basic Safety (STO)
X1 Control terminals of the safety unit
SU Basic Safety (STO) or Extended
Safety
Functional description
548
X1
SIA GS SIB
SU
µC
PWM
µC Microcontroller
PWM Pulse width modulation
M Motor
3x
M
3x