Eaton Moeller Series, Руководство пользователя

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Mean time to dangerous
failure MTTF
d
11
10/12 MN04913001Z-EN
The generally recognized inspection frequency is a hundred
times more often than the MTTF
d
. The test interval can be
determined from:
Mean time to dangerous
failure MTTF
d
The MTTF
d
time for the components is based on
with
B
10d
: Lifespan up to a dangerous failure (
a
Tables)
n
op
: Average number of annual switch operations
The MTTF
d
time for the CMD contactor monitoring device
was calculated at MTTF
d
= 125 years. This value is based on
a maximum operating frequency of 350, 400 operations/year
(1 operation per minute, 16 hours per day, 365 days a year).
The MTTF
d
time of the contactors depends on the applica-
tion. The utilization category in accordance with IEC/
EN 60947-4-1 and the operating frequency are an important
factor here. Depending on the utilization category, the
following values can be applied to B
10d
, a Tabelle 1:
T
Test
=
MTTF
d
(formula 1)
100
h
section “Mean time to dangerous failure MTTFd”
(
a page 11).
It is recommended that the test is carried out under no-
load conditions.
MTTF
d
=
B
10d
(formula 2)
0.1
x
n
op