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Chapter 6 Selection of peripheral device
6.1
Restriction in DB operation
6.1.1 DB operating time and a quiescent period
The DB usage rate is certainly made into less than 10%. Moreover, the current which can be sent through
DB unit changes by DB operating time (t).
[ DB usage rate =100 ×T1/ T2(%) ]
Figure 6.1 DB operating time chart
6.1.2
Current value which the transistor built in DBunit permits
At the time of DB operation, please select a braking resistor so that the current exceeding the
characteristic of the following table does not flow into a transistor with built-in DB unit.
Figure 6.2 VFDB2009-50 Short-time current characteristic
0
10
20
30
40
50
60
1
10
100
1000
10000
動作時間
ｓｅｃ
電
流
Ｉ
DB使用率=
% 自然冷却
連続
DB use rate = 10%(at natural cooling)
Continues 12A
D
B
c
u
rr
e
n
t
Braking time
ON
ON
T2
T1
N2
N1
DB control
Motor Speed
Summary of Contents for VFDB2009 Series
Page 1: ...VFDB2009 Operation Manual...
