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2 Engineering
2.12 Loading conditions
54
DS7 Soft starter
09/16 MN03901001Z-EN
www.eaton.com
2.12.3 Different overload current
If load cycles or start frequencies are different, the following graphs can be
used for reading the possible time current combination.
The example shown here is a 30 kW motor (400 V, 55 A) with an assigned
DS7-34xSX055… soft starter (55 A, rated operational current = motor
current). The maximum starting current of 165 A (I
LRP
)
can be achieved for
5 s at 10 starts per hour (overload factor X = 3).
e
The prospective locked rotor current I
LRP
is the motor current that occurs
when the rated operating voltage is applied and the rotor is locked
(I
LRP
= X x I
e
).
Figure 35: Real (dashed) and normalized load current
55A: AC-53a: 3 -5 : 75 - 10
S
F [%]
T
x
[s]
X
I
e
[A]
F = 10/h,
1 h = 3600 s
l
T
x
+ t
B
+ t
P
= 360 s
T
x
+ t
B
F
=
x 100 % l
T
x
+ t
B
+ t
P
5 s + 265 s
x 100 % = 75 %
5 s + 265 s + 90 s
I
LRP
X
=
l
I
LRP
=
X x I
e
= 3 x 55 A = 165 A
I
e
I
e
I
LRP
I
T
x
t
B
t
P
1 h
t
t
P
1
2
10
T
I
t
I
e
I
LRP
Содержание DS7 Series
Страница 1: ...Manual DS7 Soft starter 09 16 MN03901001Z EN...
Страница 4: ...II...
Страница 14: ...0 About this Manual 0 8 Units of measurement 10 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 36: ...1 Device series DS7 1 14 Function 32 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 64: ...2 Engineering 2 15 Example of other load cycles 60 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 96: ...3 Installation 3 6 Insulation test 92 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 122: ...6 Parameterization 6 2 Default settings of the basic device 118 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 148: ...7 Connection examples 7 3 Size 3 and 4 41 200 A 144 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...
Страница 188: ...8 SmartWire DT 8 9 Programming 184 DS7 Soft starter 09 16 MN03901001Z EN www eaton com...