Det-Tronics EQP Fire and Gas Detection/Releasing System - Manual (Page 71)

14.1 3-52 95-8533
Alternate Method
If the transmitter board must be mounted separate
from the sensor (high temperature applications, etc.),
separate the sensor only, leaving the transmitter PC
board inside the DCUEX enclosure. When using this
installation option, see Table 3-18 for maximum wiring
distances.
Mount the sensor directly to the separation kit junction
box. Use three conductor shielded cable for the
connection between the terminal block in the
separation kit junction box and P2 on the DCUEX
transmitter board. A plug with screw terminals is
provided for connecting the cable to P2 on the
transmitter board. Observe the wiring color code.
Connect the shield to the ground terminal in the
DCUEX junction box.
Figure 3-66—Sensor Separation Kits
Table 3-18—Maximum Separation Distances —
Combustible Gas Sensor to DCU (Alternate Method)
Wire Size
Maximum Separation Distance
Feet Meters
18 AWG (1.0 mm2)* 40 12
16 AWG (1.5 mm2)* 60 18
14 AWG (2.5 mm2)* 100 30
12 AWG (4.0 mm2)* 150 45
*Approximate Metric Equivalent.
SENSOR
CATALYTIC SENSOR
ELECTROCHEMICAL SENSOR
TRANSMITTER BOARD
P1
P2
4 TO 20
–
+
C1878
POINTWATCH
GND
SPARE
CAL
4-20
RET
+24
CHASSIS
CAL
4-20
RET
+24
+
GRN
–
+
GRN
–
NOTE: ALWAYS ORIENT
JUNCTION BOX WITH
CATALYTIC SENSOR
POINTING DOWN.
1
2
3
4
5
6
7
8
9
10
DCU TERMINAL BOARD
14
13
12
11
–
–
+
+
24 VDC
COM 2
COM SHIELD
COM 1
POINTWATCH CALIBRATE
4 TO 20 MA IN
–
+
SENSOR POWER
A
B
B
A
SIG – +