Introduction - Crowcon Xgard IR Instructions D'installation, D'utilisation Et D'entretien

1. Introduction

1.1 Flameproof flammable gas detector
Xgard IR is a flameproof gas detector, designed to detect hydrocarbon gases or CO
Xgard IR is powered by 24 V dc (nominally) and provides a 4-20 mA signal (sink or
source) proportional to the gas concentration. The detector is certified
T6, and is suitable for use in Zone 1, Zone 2, Zone 21 and Zone 22 hazardous areas.
Electrical connections to the detector are made via the terminal block on the PCB
shown below.
Diagram 4: Xgard IR PCB layout
Internal grounding
terminal (earth)
(Shown with PCB cover removed).
12
Test
points
.
2
II 2 GD Exd IIC
TP2
Sink
Supplemental
external
grounding
terminal (earth)
Source
TP1