PureAire Monitoring Systems, Inc.
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3.4 Wiring
3.4.1 24 VDC Power
Connect the 24 VDC power cable to the terminal block located on the inside of the instrument. The
terminal connections are as follows: (Pin 6) +24V, (Pin 5) Common, and (Pin 4) shield. A three-wire
shielded cable (3-conductor, 18 AWG stranded shielded) General Cable #E2203S.30.86 or equivalent
should be used for the connection. The total length of the cable between the gas detector and controller
must not exceed 0.62 miles (1 km).
CAUTION: The Air Check Methyl Bromide Monitor
must only be powered using a regulated
24VDC Power Supply. Failure to use a regulated 24VDC power supply will void the warranty.
The 24 VDC power in connections are made on the 6 pin terminal connection located on the Power
Supply PCB. These connections are made as follows:
Pin #
Connection
6
DC + 24V
5
Common
4
Shield
3.4.2 Alarm Relays
The Air Check monitor incorporates two gas concentration alarm relays and one system fault relay.
These relays may be wired for normally open (N.O.) or normally closed (N.C.) operation and are rated
as follows:
Rated, 2amps @ 30VDC; 2amps @ 250VAC. See page 9.
Pyrolizer & Pump Drive Board
Flow and Pyro
Factory Set
Potentiometers
Do Not adjust
Status LED’s
Power Connector
Pin 6 +24 VDC
Pin 5 Common
Pin 4 Shield
Pins 1, 2 and 3 are not used.
Fuses
Plug In type F3 F1 F2
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