Eaton Moeller Series, Руководство пользователя

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Mean time to dangerous
failure MTTF
d
13
10/12 MN04913001Z-EN
The MTTF
d
value of the undervoltage release depends on the
application. The following values can be estimated for B
10d
:
Table 2: B
10d
values for undervoltage release
At an assumed operating frequency of 3 operations per day
up to NZM2 and 1.33 operations per day for the NZM3 and
NZM4 the MTTF
d
value is:
Table 3: MTTF
d
values for undervoltage releases
Undervoltage release B
10d
value
[Switch operations]
NZM1 10000
NZM2 10000
NZM3 7500
NZM4 5000
Undervoltage
release B
10d
value Operations n
op
MTTF
d
[Switch opera-
tions] per working
day [O/year] [Years]
NZM1 10000 3 750 133
NZM2 10000 3 750 133
NZM3 7500 1.33 333 225
NZM4 5000 1.33 333 150
h
An annual inspection meets the requirements in accor-
dance with section “Average diagnostic coverage DCavg”
(
a page 10).
For further calculation of the safety function see
EN/ISO 13849.