Page 9 from 22
921316000_09_016
The connection of sensors with 3 contacts 4÷20mA, must be between «+», «-» and “S” of sensor that correspond
to «+», «-» and “S” of panel as shown in figure 5.
The cross-section of the cable depends on the cable length (see next table). The sensors with 3 contacts do not
require coaxial cables.
Sensor series with three contacts
Ranges
Cable type
From 0 to 300 meters
3 x 0,75 mm²
Up to 400 meters
3 x 1 mm²
Up to 500 meters
3 x 1.5 mm²
Up to 600 meters
3 x 2.5 mm²
The gas sensors, need a preheat time, in clear air, for about 20 seconds. After this time the sensor can sense
gases, but the maximum sense ability is after 3 hours of continuous operation. So a sample gas test should be
done after 3 hours.
The sensors BS-382, BS-383 have maximum sense ability, in clear air, after about 1-2 hours of continuous
operation.
After the electrical connection of the sensors, the technician must power the panel and setup all sensors.
About sensor setup see paragraph 2.6.1.
Figure
5
: Connection diagram with three pad sensor
+
+
-
-
S
S
BS-390
S
