Baldor 18H Series Installation & Operating Manual page 133

Section 1
General Information
Dynamic Braking (DB) Hardware Continued
A-2 Appendix A
General Machinery Load Calculations:
1. Calculate braking duty cycle:
Duty Cycle +
2. Calculate deceleration torque:
RPM change
+
T
Decel
308
where: T
Decel
Wk 2
time = In seconds
3. Calculate Watts to be dissipated in dynamic braking resistor:
Watts + T
Decel
where: S = Speed to start braking
max
S = Speed after braking
min
4. Multiply Watts calculated in step 3 by 1.25 to allow for unanticipated loads
(safety factor).
Braking Time
Total Cycle Time
Wk 2
* Friction
time
= Deceleration torque in lb.-ft.
= Inertia in lb.ft. 2
) S
(S )
Duty Cycle
max
min
(Lb.Ft.)
(0.0712)
MN718