Connecting Sensors to the Monitor
Connecting 4-20mA Transmitter (Gas Sensors)
(Toxic or LEL Combustible Control Modules)
Three (3) pin screw type terminals are provided on the main connection
board for remote sensor connection. The terminals are labeled as CH-1
thru CH-16 and each pin is identified as
+, - , & E
for sensor DC supply,
ground, and 4-20mA input signal respectively. The DC is supplied to the
sensor by the control module. The supply is fused through a 2 amp
miniature fuse on the control module.
Each remote sensor should be connected by a 3 conductor shielded cable.
See figure 4 sensor connection 4-20mA transmitters.
Figure 4. Sensor connection 4-20mA Transmitter
−
+
mA
S
IG
N
A
L
SENSOR
3 CONDUCTOR
SHIELDED CABLE
4−20mA
SENSOR / TRANSMITTER
SENSOR INPUT TERMINAL ON
PT920 MAIN CONNECTION BOARD
−
E
CH−1
+
TYPICAL SENSOR
CONNECTION BOARD
12
