Pilz PNOZ m EF 4DI4DOR - Manual (Page 19)

Supplementary data
Operating Manual PNOZ m EF 4DI4DOR
1002702­EN­02 19
9 Supplementary data
9.1 Service life graph of output relays
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.
Example
} Inductive load: 0,2 A
} Utilisation category: AC15
} Contact service life: 1,000,000 cycles
Provided the application requires fewer than 1,000,000 cycles, the PFH value (see tech­
nical 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 contact­
ors, use freewheel diodes for spark suppression.
We recommend you use semiconductor outputs to switch 24 VDC loads.