65-2646XL-05-04 M2A Transmitter Operator’s Manual
Chapter 2: Description
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10
CO Detector
The CO detector consists of the detector housing body, detector housing cap, cap gasket, charcoal
filter with rubber boot, and the plug-in sensor.
Figure 2: CO Detector Component Location
Detector Housing Body
The detector housing body protects the electronic components within the housing. Use the
mounting threads at the top of the housing to screw the CO detector into the 3/4 NPT hub on the
bottom of the detector junction box. Two wires extend from the top of the detector housing body.
Use these wires to connect the CO detector to the terminal strip. One of the wires is red and one of
the wires is black.
The housing includes a four-socket pattern. This socket pattern accepts the sensor’s four pins to
secure the sensor within the detector housing. A pre-amplifier, located between the sockets and
two interconnect wires, conditions the sensor’s signal before the signal reaches the controller.
Housing Cap & Cap Gasket
The housing cap screws onto the detector housing. It retains the plug-in sensor and protects it
from damage. The housing cap also includes a flame arrestor which contains any sparks that may
occur within the detector and a flame arrestor guard which protects the flame arrestor from
damage. Unscrew the detector cap to access the plug-in sensor for maintenance or replacement. A
cap gasket seals the interface between the housing and cap. A flame arrestor guard is permanently
bonded to the cap.
Charcoal Filter and Rubber Boot
The disc-shaped charcoal filter is secured to the face of the CO sensor with a rubber boot. The
charcoal filter prevents interference gases (hydrogen sulfide [H
2
S] and certain hydrocarbons)
from producing false CO readings.
Plug-In CO Sensor
Rubber Boot W ith
Charcoal Filter
Detector Housing Cap
Detector Housing Body
Cap Gasket
Flame Arrestor
Guard
