Detcon TP-624D - Manual (Page 14)

Model TP-624D
TP-624D Instruction Manual Rev. 0.4 Page 10 of 40
high voltage lines or other possible sources of induced interference. Separate conduit runs are
highly recommended in these cases.
NOTE 3: The supply of power should be from an isolated source with over-current protection
as stipulated in table.
NOTE 4: A 250 ohm load resistor is needed between the 4-20 mA and the Power ‘-‘ terminals
when the 4-20mA signal is not being used.
Terminal Connections
CAUTION: Do not apply System power to the sensor until all wiring is properly terminated. Refer
to Section 2.7 Initial Start Up
Customer
Wiring
W
h
ite
B
lu
e
Y
e
llo
w
B
la
c
k
Wiring to
H2S Sensor
Power (+ -)
4-20 mA
RS-485 (A,B)
F
a
u
lt
A
la
rm
2
A
la
rm
1
Figure 9 Sensor Connector PCB
a) Remove the junction box cover and unplug the Transmitter Module. Identify the terminal blocks for
customer wire connections.
b) Observing correct polarity, terminate the field wiring (DC+, DC-, MA, A, and B) to the sensor assembly
wiring in accordance with the detail shown in Figure 9.
c) Trim all exposed wire leads if they are not permanently landed in the terminal block.
d) Plug the Transmitter Module into the connector PCB and replace the junction box cover.
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.