Siemens SIMOTICS S-1FK2 - Page 78

Calculating the braking time
The values for calculation are provided in Chapter "Data sheets and characteristics (Page 95)".
Braking time t
B
= J
tot
• n / (9.55 • M
Br
) t
B
/ s = braking time
n / r/min = operating speed
M
Br
/ Nm = average braking torque
Moment of iner‐
tia
J
Tot
= J
Mot
+ J
Ext
J
Tot
/ kgm
2
= moment of inertia
J
Mot
/ kgm
2
= motor moment of inertia
J
Ext
/ kgm
2
= external moment of inertia
Note
In determining the run-on distance, consider the friction of the mechanical transmission
elements (included in the calculation as an allowance in M
B
) and the switching delay times of the
contactors.
To avoid mechanical damage to the drive, mount mechanical stops at the end of the absolute
traversing range of the machine axes.
Con󹪝guration
5.4 Brake resistances (armature short-circuit braking)
1FK2 Synchronous Motors for SINAMICS S120
76 Con󹪝guration Manual, 02/2022, A5E46927724B AD