Rockwell Automation 1305 DYNAMIC BRAKES - Manual (Page 5)

1305 Dynamic Brake 5
1305-5.11 May, 1999
0
30
10
20
10 30 50 60 80 100 20 40 70 90
5
15
25
55
35
45
40
50
80
60
70
65
75
90
85
95
P% 100
0
Decel Time t
2
in Seconds
Step 7 — Determine the Ratio of the Average Power to the Brake
Assembly Rating.
where:
P A = The average power generated in one
cycle.
N2 = The brake assembly rating from table 1.
P% = %
P% = P A
——
P
T
P% = [ ]
———
[ ]
How to Select a Brake
(continued)
Find the intersection of P% and the motor’s decel time t
2
in the chart
below. If the point of intersection is below the curve, the average power
of one cycle is within the brake’s limits. If the point is above the curve,
the average power is beyond the brake’s limits but may be reduced by
increasing the motor’s decel time
t
2
, reducing the load inertia wk 2
L , or
doing both.