Rockwell Automation 1333 Drive, 3/4-5HP, 230-575V Series D - Manual (Page 133)

Application Data
Appendix D
D-6
Step 6 -- Determine the Average Power Generated in One Cycle
P
A
= [ ] × [ + ]
14,000
P
A
= TQ
B
× [N
1
+ N
2
]
14,000
TQ
B
= The required braking torque
N
1
= The motor's minimum speed
N
2
= The motor's maximum speed
P
A
= kW
Step 7 -- Determine the Ratio of the Average Power to the Brake
Assembly Rating
P
%
= [ ]
[ ]
P
%
= P
A
P
T
P
A
= The average power generated in one cycle
P
T
= The brake assembly rating from table 1
P
%
= %
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 2L
, or
doing both.
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