Detcon TP-700 - Manual (Page 14)

Model TP-700
TP-700 Instruction Manual Rev. 3.5 Page 10 of 38
Customer
Supplied Wiring
(Out to next Device)
(+
)
m
A
(-
)
A
(+
)
B
(-
)
Wiring to
Sensor Assembly
W
h
t
B
lu
R
e
d
G
rn
B
lk
Explosion
Proof
Junction Box
(+)
mA
(-)
A(+)
B(-)
(+)
mA
(-)
A(+)
B(-)
Customer
Supplied Wiring (In)
Modbus RS-485 to
Host Control Device
Power from and 4-20mA
out to Control Device
Install a 100-250 Ohm
resistor if the 4-20mA
output is not used
Modbus RS-485 to
next Device
Figure 8 Sensor Wire Connections
a) Remove the junction box cover. Identify the terminal blocks for customer wire connections.
b) Observing correct polarity, terminate the 3-conductor 4-20mA field wiring (+, -, and mA) to the sensor
assembly wiring in accordance with the detail shown in Figure 8. If the 4-20mA output is not used, the
green wire from the sensor must be connected to the (-) terminal on the Transient Protection Module.
NOTE: If the 4-20mA output is not being used, the Green wire from the sensor must be
connected to the Black wire at the (-) terminal on the Transient Protection Module to
ensure RS-485 communication is not disrupted by a 4-20mA Fault.
c) If applicable, terminate the RS-485 serial wiring as shown in Figure 8. Use the second plug (Out) as
termination point on the customer side to facilitate a continuous RS-485 serial loop.
The RS-485 (if applicable) requires 24 gauge, two conductor, shielded, twisted pair cable between sensor and
host PC. General Cable Commodore part number ZO16P0022189 is recommended.
NOTE: Install a 120Ω resistor across A & B terminals on the last sensor in the serial loop.
d) Trim all exposed wire leads if they are not permanently landed in the terminal block.
e) Replace the junction box cover.
NOTE: A 6-32 threaded exterior ground point is provided on the sensor housing for an
external ground. If the Sensor Housing is not mechanically grounded, an external ground strap
must be used to ensure that the sensor is electrically grounded.
2.7 Initial Start Up
Upon completion of all mechanical mounting and termination of all field wiring, apply system power in the
range of 11.5-30VDC (24VDC typical) and observe the following normal conditions: