Siemens SIPROCESS GA700 Compact Operating Instructions page 110

Ex px safety equipment
B.1 Overview
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 B-3 Electrical connections of an Ex p safety equipment, Gönnheimer Elektronik GmbH
Ex power relay SR853
Connections
110
16
18
15
8, 9, 10, 11
2, 25, 3, 24
1, 26; 12, 15; 13, 14
Power supply cable N
Power supply cable L
Protective conductor PE
Doubly-protected power contacts for the power dis‐
connection of the analyzer device (required to ab‐
sorb high inrush current peaks)
Control connections for Ex power relay
Protective conductor PE
SIPROCESS GA700 rack and wall mounted devices
Compact Operating Instructions, 06/2023, A5E35134047-AB