Section 1
General Information
A-2 Appendix MN715
Dynamic Braking (DB) Hardware Continued
General Machinery Load Calculations:
1. Calculate braking duty cycle:
Duty Cycle +Braking Time
Total Cycle Time
2. Calculate deceleration torque:
TDecel +RPM change Wk2
308 time *Friction (Lb.Ft.)
where: TDecel = Deceleration torque in Lb.-ft.
Wk2 = Inertia in Lb.ft.2
time = In seconds
3. Calculate watts to be dissipated in dynamic braking resistor:
Watts +TDecel (Smax *Smin ) Duty Cycle (0.0712)
where: Smax = Speed at braking start
S
min = Speed after braking
4. Multiply watts calculated in step 3 by 1.25 to allow for unanticipated loads
(safety factor).