RKI Instruments 35-3000RK-LEL/O - Manual (Page 9)

35-3000RK-LEL/O Sample-Draw Detector • 5
Connector
The top of the sensor includes five pins that plug into the socket connector. This connector
allows you to replace the sensor without disconnecting the wiring. The sensor leads are
soldered to the connector.
Sensor leads
Four color-coded leads extend from the connector. The leads allow you to connect the
combustible gas sensor to the main circuit board.
Oxygen Sensor
The oxygen sensor is installed in the flow block to the right of the combustible gas sensor.
The oxygen sensor includes the oxygen cell, connector, and sensor leads.
Oxygen cell
The oxygen cell is protected within the sensor assembly. Through a series of chemical and
electronic reactions, the cell produces a millivolt output that is proportional to the
detection range of the sample-draw detector.
Connector
The cable that extends from the sensor terminates in a 7-position socket that connects to a
mating 7-pin male connector. The socket and connector allow you to replace the sensor
without disconnecting the wiring. The sensor leads are soldered to the male connector.
Sensor leads
Two color-coded leads extend from the connector. The leads allow you to connect the
oxygen sensor to the main circuit board.
Main Circuit Board
The main circuit board includes the interconnect terminal strip, detector terminal strip,
pump terminal strip, and relay (see Figure 1).
NOTE: The flowmeter and status lights are mounted to the main circuit board but are
considered part of the flow system.
Interconnect terminal strip
The interconnect terminal strip is the nine-point terminal strip near the bottom edge of the
main circuit board. Use the interconnect terminal strip to connect the sample-draw
detector to a controller.
Detector terminal strip
The detector terminal strip is the nine-point terminal strip near the right edge of the circuit
board. Use the detector terminal strip to connect the combustible gas sensor and the
oxygen sensor to the main circuit board.
NOTE: The combustible gas sensor and oxygen sensor are factory-wired to the circuit
board. See the “Installation” section on page 7 for all wiring procedures related
to the sample-draw detector.
Pump terminal strip
The pump terminal strip is the four-point terminal strip near the top edge of the circuit
board. Use the pump terminal strip to connect the pump and pressure switch to the main
circuit board.