PNOZ X3.1
Operating Manual PNOZ X3.1
20133-EN-06
21
Supplementary data
CAUTION!
It is essential to consider the relay's service life graphs. The relay outputs'
safety-related characteristic data is only valid if the values in the service life
graphs are met.
The PFH value depends on the switching frequency and the load on the relay output.
If the service life graphs are not accessible, the stated PFH value can be used irrespective
of the switching frequency and the load, as the PFH value already considers the relay's
B10d value as well as the failure rates of the other components.
Service life graph
The service life graphs indicate the number of cycles from which failures due to wear must
be expected. The wear is mainly caused by the electrical load; the mechanical load is negli-
gible.
Number of cycles x 1000
Switching current (A)
Example
}
Inductive load: 0.2 A
}
Utilisation category: AC15
}
Contact service life: 4 000 000 cycles
Provided the application to be implemented requires fewer than 4 000 000 cycles, the PFH
value (see Technical details) can be used in the calculation.
To increase the service life, sufficient spark suppression must be provided on all output
contacts. With capacitive loads, any power surges that occur must be noted. With DC con-
tactors, use flywheel diodes for spark suppression.
