Det-Tronics Eagle Quantum 95-8470-05, Инструкция по эксплуатации

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VII-26
Sensor Separation with DCUEX
If the installation requires mounting the sensor in a
different location than the DCUEX, observe the following
guidelines.
When separating a combustible gas sensor from the
DCUEX, two options exist:
1. Preferred Method
Mount the transmitter PC board inside the sensor
separation junction box. This assembly can be
separated from the DCUEX by up to 1000 feet using
three conductor 18 AWG shielded cable.
(Regardless of separation distance, operating
voltage at the transmitter MUST be at least 18 vdc
to ensure proper operation.) See Figure VII-39.
Assemble the DCUEX without the transmitter board
similar to the DCU as shown in Figure VII-33. Plug
the sensor into P2 on the transmitter board. Use a
three conductor 18 AWG shielded cable to connect
P1 on the transmitter board to terminals 2, 3 and 4
on the DCU terminal board (see Figure VII-39).
Connect the shield to the ground terminal in the
DCUEX junction box.
2. 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 VII-9
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 P1 on the transmitter
board. A plug with screw terminals is provided for
connecting the cable to P1 on the transmitter board.
Observe the wiring color code. Connect the shield
to the ground terminal in the DCUEX junction box.
SENSOR
CATALYTIC SENSOR
ELECTROCHEMICAL SENSOR
TRANSMITTER BOARD
P1
P2
+
–
4 TO 20
B1878
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.
Figure VII–39—Sensor Separation Kits
Table VII–9—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.