RKI Instruments 65-2390RK - Manual (Page 7)

65-2390RK Combustible Gas Transmitter • 3
applied to the white wire of the propane detector near where the wire comes out of the
nipple.
Amplifier
The amplifier converts the electrical output from the detector to a 4 to 20 mA signal that
corresponds to the detection range and transmits the signal to a gas monitoring controller.
The amplifier includes the interconnect terminal strip, span potentiometer, zero
potentiometer, and test points (see Figure 1).
Interconnect Terminal Strip
The interconnect terminal strip is a seven-point terminal strip. Use the interconnect
terminal strip to connect the IR LEL detector to the amplifier and the amplifier to a
controller.
NOTE: The IR LEL detector is factory-wired to the amplifier. See the Installation section
of this manual for all wiring procedures related to the transmitter.
Span Potentiometer
The span potentiometer is near the bottom of the amplifier (see Figure 1). Use the span
potentiometer to adjust the transmitter’s response output during the calibration
procedure. Turn the adjustment screw clockwise to increase the gas response and
counterclockwise to decrease the gas response.
Zero Potentiometer
The zero potentiometer is to the right of the span potentiometer (see Figure 1). Use the
zero potentiometer to adjust the transmitter’s target gas-free output during the start-up
and calibration procedures. Turn the adjustment screw clockwise to increase the zero
output and counterclockwise to decrease the zero output.
CAUTION: The amplifier includes two additional potentiometers. They are factory-set. Do not
adjust them.
Test Points
The test points (labeled TP+ and TP-) are to the left of the interconnect terminal strip
(see Figure 1). The test points produce a 100 to 500 mV output that corresponds to the
transmitter’s 4 to 20 mA output. Use the test points and a voltmeter to measure the
transmitter’s output during the start-up and calibration procedures.
Junction Box
Use the junction box to install the combustible gas transmitter at a mounting site that is
remote from the controller. The junction box also protects the amplifier and wiring
connections made to the amplifier. Use the two 3/4 in. conduit hubs to mount the detector
to the junction box (bottom hub) and connect wiring from the amplifier to the controller
(top hub).
NOTE: The detector and amplifier are factory-mounted to the junction box.
Use the junction box’s two mounting holes to mount the combustible gas transmitter to a
vertical surface at the monitoring site. Use the cover on the front of the junction box to
access the interior of the junction box.