Siemens SIPROCESS GA700 Compact Operating Instructions page 103

Connection information
The supply pressure has to be sufficiently large (2.5 ... 5 bar).
The supply line before the pressure regulating valve has to be dimensioned so that the line
pressure in the inlet does not drop below 2.5 bar during pre-purging (sufficiently large
diameter of the supply line).
If purging gas lines are used with a smaller diameter or longer length than specified,
pressure builds up in the Ex p enclosure that lies outside the setpoint range specified in the
Ex p control system.
Electrical connections of the Ex p control system with peripherals (example)
Figure A-3 Electrical connections of an Ex p safety equipment, Gönnheimer Elektronik GmbH
Ex p controller F870S
Connections
Connection
Devices in explosion-proof design
Compact Operating Instructions, 05/2018, A5E35134047-03
19, 20
21, 22
23, 24
28, 30 to 29, 31
L
Power supply cable N
Power supply cable L
Power supply cable PE
Doubly-protected contacts for enabling line-
voltage-operated blocks such as isolating relays
and Ex power relays
Fuse with 16 A!
Appendix A
A.1 Ex py safety equipment
103