48
Motor Contactor
J7KN
Contactors
Data according to IEC 947-4-1, EN 60947-4-1, VDE 0660
Contact Life
For selection of the suitable contactor-type according to supply volt-
age, power rating and application (utilization category AC1, AC3 or
AC4) use contact life characteristic diagram.
For the most common supply voltages four scales of power ratings P
n
are provided for each utilization category.
Select contactor-type according to utilization category
AC3
(breaking
current I
a
= I
e
) using the
motor rating
scales to the right, according
to utilization category
AC4
(breaking current I
a
= 6 x I
e
) using the
motor rating
scales to the left.
*1
Select contactor-type according to utilization category
AC1
(breaking
current I
a
= I
e
/AC1) using the
breaking current
scale.
*1
For contactors frequently used under AC3/AC4-mixed service condi-
tions calculate contact life with the formula:
1.
Pay attention to the approved rated values of the selected
contactor according to the national approvals
M
AC3
1
%AC4
100
-----------------x
AC3
AC4
-----------
1
–
⎝
⎠
⎛
⎞
+
---------------------------------------------------------
=
M = Contact life (switching cycles) for AC3/AC4-mixed operations
AC3 = Contact life (switching cycles) for AC3 operations (normal switching
conditions). Breaking current I
a
= rated motor current I
n
.
AC4 = Contact life (switching cycles) for AC4 operations (inching).
Breaking current I
a
= multiples of rated motor current I
n
.
%AC4 = Percents of AC4-operations related to the total cycles.
A
Motor Rating
P
n
/AC4
Motor Rating
P
n
/AC3
Breaking Current
I
a
(=I
e
/AC1)
J7KN-74
J7KN-24
J7KN-32
J7KN-40
J7KN-50
J7KN-62
J7KN-22
J7KN-18
J7KN-14
J7KN-12
J7KN-10
J7KN-09
millions of operations
A
Motor Rating
P
n
/AC4
Motor Rating
P
n
/AC3
Breaking Current
I
a
(=I
e
/AC1)
J7KN-200
J7KN-150
J7KN-175
J7KN-110
J7KN-85
millions of operations
