35-3010RK-01 Sample-Draw Detector • 7
Interconnect Terminal Strip
The interconnect terminal strip is the sixteen-point terminal strip near the bottom edge of
the main circuit board. Use the interconnect terminal strip to connect the sample-draw
detector to power and a controller.
Sensor/Transmitter Terminal Strip
The sensor/transmitter terminal strip is the sixteen-point terminal strip near the right
edge of the circuit board. Use the transmitter terminal strip to connect sensors or
transmitters to the main circuit board.
NOTE:
The sensors and transmitters are factory wired to the sensor/transmitter
terminal strip. See “Wiring the Sample-Draw Detector to a Controller” on page 9
for all wiring procedures related to the sample-draw detector.
Amp 1 and Amp 2 Circuits
These circuits are located to the left of the sensor/transmitter terminal strip. They each
include test points, a zero pot, and a span pot. Amp 1 is on the left and is for the CO
channel. Amp 2 is on the right and is for the H
2
S channel.
The zero and span pots are used during calibration. Use the span pot to make adjustments
to gas response readings and the zero pot to make adjustments to the zero reading.
The test points are labeled CAL-1 and CAL+1 for the CO channel and CAL-2 and CAL+2
for the H
2
S channel. A 100 mV - 500 mV output is available at each set of test points for
use during calibration.
Pump Terminal Strip
The pump terminal strip is the four-point terminal in the top left corner of the circuit
board. Use the pump terminal strip to connect the pump and pressure switch to the main
circuit board.
NOTE:
The pump and pressure switch are factory-wired to the circuit board. See
“Wiring the Sample-Draw Detector to a Controller” on page 9 for all wiring
procedures related to the sample-draw detector.
Relay
The relay is approximately in the middle of the circuit board. The relay is a four pole,
double-throw (4PDT) relay and is rated for 2 amps at 25 VDC (resistive). If the pressure
switch senses a low flow condition, the relay interrupts the 4-20 mA signal from the CO
and H
2
S channels and opens one of the lines from the LEL and oxygen sensors which will
cause a downscale reading at the controller on these channels.
Reset Switch
A small reset button is located in the upper left corner of the main PCB. When a low flow
condition occurs, the pump will be shut off. To reset the low flow condition and start the
pump again, press and hold the reset switch for about 2 seconds, then release.
