Siemens SIMOTICS 1FT2104-4AF - Brake; Type of Holding Brake

Motor components and options
4.2 Brake
1FT2 synchronous motors for SINAMICS S120
50 Configuration Manual, 03/2021, A5E50645584B AA
4.2 Brake
4.2.1 Type of holding brake
The type of holding brake installed depends on the size of the motor.
Type of the holding brake
Spring-loaded brake
Permanent-magnet brake
installed in the motors
1FT2☐03 ... 1FT2☐04
1FT2☐05 ... 1FT2☐10
Method of operation
The spring exerts a tensile force on
the brake armature disk. This
means that in the no-current condi-
tion, the brake is closed and the
motor shaft is held.
When 24 V DC rated voltage is
applied to the brake, the current-
carrying coil produces an opposing
field. This neutralizes the force of
the spring and the brake opens
without any residual torque.
The spring-loaded brake has a tor-
sional backlash less than 1°.
The magnetic field of the per-
manent magnets exerts a pulling
force on the brake armature
disk. This means that in the no-
current condition, the brake is
closed and the motor shaft is
held.
When 24 V DC rated voltage is
applied to the brake, the cur-
rent-carrying coil produces an
opposing field. This neutralizes
the force of the permanent
magnets and the brake opens
without any residual torque.
The permanent magnet brake
has a torsionally stiff connection
to the motor rotor.
NOTICE
Damage to the motor due to axial forces on the shaft extension
Axial forces on the shaft extension can damage motors with an integrated holding brake.
• Avoid impermissible forces on the shaft extension. Detailed information is provided in
Chapter "Axial forces (Page 36)".
• The holding brake is used to clamp the motor shaft when the motor is at a standstill. The
holding brake is not a working brake for braking the rotating motor. When the motor is at
a standstill, the holding brake is designed for at least 5 million switching cycles.
• A limited number of EMERGENCY STOP operations is permissible.