I Current
t Time
t
0
Opening time
t
c1
Closing time
A Brake opened
Figure 4-1 Terminology (time) for holding operation
Holding torque M
4
The holding torque M
4
is the highest permissible torque for the closed brake in steady-state
operation without slip (holding function when motor is at standstill). The data applies for the
state at operating temperature (120 °C).
Dynamic braking torque M
1m
The dynamic braking torque M
1m
is the smallest mean dynamic braking torque that can occur for
an EMERGENCY STOP.
Opening time and closing time
The delay times that occur when switching the brake.
Maximum permissible single switching energy
The maximum permissible single switching energy of an individual EMERGENCY STOP
operation.
After an EMERGENCY STOP with the maximum single operating energy, allow a cooling time of
at least 3 minutes before you operate the motor again.
Total operating energy (service life)
The total switching energy is the sum of the single switching energy (switching energy for each
EMERGENCY STOP procedure). If the total operating energy is exceeded, brakes can no longer
be guaranteed to function correctly.
• Refurbish the motor.
Formula for calculating the operating energy per braking operation
W
BR
= (J
Mot Br
+ J
load
) • n
mot
² / 182.4
W
Br
/ J Operating energy per braking operation
n
Mot
/ min
-1
Speed at which the brake is engaged
J
Mot Br
/ kgm
2
Rotor moment of inertia of the motor with brake
Motor components
4.2 Holding brake
1FK2 Synchronous Motors for SINAMICS S120
Conguration Manual, 02/2022, A5E46927724B AD 63