Pilz PSS67 F 16DI SB-T - Manual (Page 28)

Wiring
7 - 2 Operating Manual: PSS67 F 16DI SB-T
Notes on wiring
Where safety-related applications are concerned, it is essential that short
circuits and open circuits are unable to cause a hazardous condition within
a plant.
WARNING!
Safe separation is required when connecting a device with a circuit with
over 25 V AC or 60 V DC
The following terms are important:
• Signal inputs with frequent operation
These are signals that change status on several occasions within a
period of time.
• Single-channel safe input devices
These are positively-driven, normally-closed contacts which open on
actuation (failsafe principle).
• Elimination of short circuits between signals
This is possible within electrically-enclosed areas and also outside
electrically-enclosed areas for signals conducted in different multicore
cables. However, all components must meet the relevant regulations in
accordance with EN, DIN and VDE.
• In principle, the possibility of earth faults and open circuits cannot be
eliminated. With multi-channel input devices with frequent operation,
short circuits and open circuits can be detected via feasibility checks in
the control program.
The input test on the module uses test pulses to enable the operating
program of the PSS67 F 16DI SB-T to carry out a test to detect open
circuits and short circuits. The following pages contain details of
connection examples which may be of use when wiring the unit.
Labelling the module
You can label the SafetyBUS p and supply voltage connections, as well as
the inputs. 12 blank labels are supplied with the module. In addition you
can order a DIN A4 sheet with 264 labels as an accessory (order
no. 331 250).