20
2.4 Electrical connections
All connections are made via the screw terminal block mounted on the
amplifier PCB in the junction box. The terminals are marked ‘+’ and ‘’
and correct polarity should be observed when connecting the detector to
control equipment. This version of
Xgard
is a 420 mA current sink
device, and requires a dc supply of 830 V.
Note: The internal grounding terminal (see diagram 6) shall be used as the
grounding means of the
Xgard
gas detector. The external grounding
terminal (see diagram 6) is only a supplemental bonding connection, and
is only to be used where local authorities permit or require such a
connection. To limit radio frequency interference, the junction box and
cable armour should be grounded (earthed) at the control panel. Ensure
the earth connection is in a safe area only, so as to avoid earth loops.
Diagram 7:
Xgard
Type 2
electrical connections
2. Installation
Xgard Type 2
SIG
Xgard
Type 2 PCB
Control Panel
Earth
830 V dc
420 mA
(Source)
