PureAire Monitoring Systems, Inc.
9
3.3 Wiring
The
Air Check
O
2
monitor requires a single, 3-wire shielded cable for analog output
and 24 VDC power input. A three-wire shielded cable; 3-conductor, 18 AWG stranded
General Cable E2203S.30.860, or equivalent
is recommended for the connection. The
analog out and VDC power in connections are made on the terminal block inside the
transmitter housing.
These connections are made as follows:
*
Caution:
DO NOT connect to a powered current loop receiver. The Air Check
Oxygen monitor supplies the current loop power.
3.4 Initial Startup
Once installation of the gas detector has been completed, it is ready for startup. The following
procedures should be performed before putting the instrument into operation:
1.
Check the integrity of all wiring.
2.
Apply VDC power.
The instrument should now be powered up. Upon power up, the
Air Check
O
2
monitor LCD
displays the PureAire logo and then starts a 4-minute, (240 second) count down as the current to the
zirconium oxide O
2
sensor stabilizes. The monitor will output a 4-mA signal during the entire warm-
up period. After the countdown, the oxygen sensor will continue to reach its operating temperature for
approximately 30 minutes and the reading displayed will slowly increase to ambient.
Do not make
any adjustments to the reading until after the monitor has been powered for at least an hour.
NOTE:
The
Air Check
O
2
monitor’s reading may be adjusted to the ambient oxygen level.
See section 6.1 for instructions on adjusting.
Oxygen
239 WARM
-
Common
-
Common
mA
*
4-20mA signal
output to PLC
+
24VDC Power
+
24VDC Power
Identification Legend
PureAire provides
the plug-in power
supply
