Technical data
8.8 Electrical service life of contactor
M200D PROFIBUS/PROFINET
184 Manual, 08/2014, A5E01577426A/RS-AA/004
If
is available, i.e. if normal switching operation (breaking of rated operating
current in accordance with utilization category AC-3) is mixed with occasional inching
(breaking of the multiple rated operating current in accordance with utilzation category AC-
4), the service life of the contacts can be calculated approximately with the following formula:
X Contact service life for mixed operation in operating cycles
A Contact service life for normal operation (I
a
= I
e
) in operating cycles
B Contact service life for inching (I
a
= multiple of I
e
) in operating cycles
C Proportion of inching operations in the total operations as a percentage
P
N
Rated power of three-phase motors at 400 V
I
a
Breaking current
I
e
Rated operating current
Figure 8-2 Service life of main contacts for contactor 3RT1017
To Next Page
Loading...
