Det-Tronics EQP Fire and Gas Detection/Releasing System - Manual (Page 69)

14.1 3-50 95-8533
EQ22XXDCUEX DIGITAL COMMUNICATION UNIT
(USED WITH DET-TRONICS COMBUSTIBLE GAS
SENSORS)
MOUNTING
Determine the best mounting location for the device.
Whenever practical, the device should be placed
where it can easily be reached for calibration.
IMPORTANT!
Always orient the junction box with the sensor
pointing down.
WARNING!
Do not apply power to the system with the cover
removed unless the area has been verified to be
free of combustible gases or vapors.
WIRING
1. Remove the cover from the DCUEX.
CAUTION!
ALWAYS discharge static from tools and hands
by touching the device body before touching the
communication module or transmitter board.
2. Loosen the screws on the communication module
and remove it from the transmitter board
standoffs.
3. Disconnect the ribbon cable from the
communication module.
4. Remove the standoffs and detach the transmitter
board from the terminal wiring board. Do not
disconnect any wiring.
5. Connect all external wiring to the terminal wiring
board. (See Figure 3-64.)
NOTE
Make sure the ribbon cable is connected to the
terminal wiring board.
6. Attach the sensor to the device enclosure. DO
NOT overtighten.
NOTE
If a sensor separation kit is being used, attach
the sensor to the separation kit junction box.
(See Sensor Separation with DCUEX below.)
7. Plug the sensor into P2 on the transmitter board.
8. Mount the transmitter board to the terminal wiring
board and attach with the standoffs.
NOTE
Be sure to note the correct orientation of the
transmitter board. If the transmitter board is
rotated 180° from proper orientation, the device
w i l l n o t o p e ra te c o rre c t ly — a LO N
communication fault will result. See Figure 3-65.
9. Plug the ribbon cable into the communication
module and re-attach it to the transmitter board.
10. Set the device network address. (See “Setting
Device Network Addresses” in this section.)
11. Inspect the junction box O-ring to be sure that it is
in good condition. Lubricate the O-ring and the
threads of the junction box cover with a thin coat
of silicone-free grease (available from Det-
Tronics).
12. Replace the device cover.
1
2
3
4
5
6
7
8
9
10
SIG
–
+
DCU TERMINAL BOARD DCU TRANSMITTER BOARD1
(MIDDLE BOARD)
14
13
12
11
–
–
+
+
24 VDC
POINTWATCH CALIBRATE
4 TO 20 MA IN
–
+
A
B
A
B
SENSOR POWER
COM 2
COM SHIELD
COM 1
B1877
NOTES: 1 Catalytic Combustible Gas Sensor
Plugs into Connector Pins on the
Middle Board inside the Junction Box.
2 Connections Wired at the Factory.
2
2
2
Figure 3-64—DCU Transmitter Board Connected
to Terminal Wiring Board