Detcon DM-100 - Manual (Page 15)

Model DM-100
DM-100 Instruction Manual Rev. 3.3 Page 11 of 40
1. Remove the junction box cover.
2. If the sensor has the Display option installed, unplug the display from the terminal board by pulling the
display out of the junction box. The display option plugs directly into the terminal board’s Beau
Connector.
3. Observing correct polarity, terminate the 2-conductor power and 4-20mA field wiring (+ and mA) at the
terminal board connector J1 (4-20mA Out) on the Standard Terminal Board shown in Figure 7, or J7
(PWR and MA) on the Display Terminal Board shown in Figure 8.
4. Trim and cap all exposed wire leads if they are not permanently landed in the terminal board.
5. The sensor should be connected to J2, labeled SENSOR on the Standard Terminal Board, and J6, labeled
SENSOR, on the Display Terminal Board. On the Standard Terminal Board, the wiring from the sensor
should match the silkscreen on the terminal board: R–Red, BK–Black, GN-Green, BU–Blue, and W–
White. On the Display Terminal Board the wiring should be: Red-PWR, Black-GND, White–A, Blue–B
(Green is not connected).
6. On the Display Terminal Board other connectors are provided for factory installed options. The options
ordered will dictate if, and what connectors are used. The display option is plugged into the Beau
connector (J3) for a DM-100 with just the display option added. Other options are covered in the
associated manual for those options.
7. If a display was removed in Step 2, re-install the display by plugging it back into the terminal board.
8. Replace the junction box cover after initial startup.
NOTE
A 6-32 or 8-32 threaded exterior ground point is provided on most junction boxes for an
external ground. If the Sensor Assembly is not mechanically grounded, an external ground
strap must be used to ensure that the sensor is electrically grounded.
2.6.1 DM-100 Display Terminal Board Settings
The Model 100 Display Terminal Board contains a jumper that must be configured properly for the board to
operate correctly. The jumper is normally configured at the factory and should not be changed. Misplacement
of the jumper may cause the sensor to become inoperative.
Table 2 Model 100 Terminal Board Jumper
JP1 1-2 – Battery installed 2-3 – Display only
2.7 Initial Start Up
2.7.1 Toxic Gas Sensors
Upon completion of all mechanical mounting and termination of all field wiring, apply system power in the
range of 11-26VDC (24VDC typical) and observe the following normal conditions:
1. If the Loop Powered Display option is installed, the display should read 0.0 upon power up. If a Loop
Powered Display is not installed on the sensor, set a DVM to measure millivolts, and connect it across
TP1 and TP2 on the terminal board. The DVM will read the voltage drop across a 10Ω resistor. The
resistor develops a 10mV voltage drop per 1mA of current. Thus a reading of 40mV on a DVM equals
4mA of current.