INSTALLATION & OPERATING DATA
6 CONNECTIONS
continued
6.4.2
GROUP II HAZARDOUS AREAS (24 V dc)
TX6373.02 TOXIC GAS SENSOR/ TRANSMITTER
This version of the sensor (4 to 20 mA) is certified Intrinsically
Safe for use in Group II hazardous areas, when used in
conjunction with safety barriers.
THE SAFETY BARRIERS ARE MOUNTED IN THE SAFE AREA,
ONLY THE SENSOR IS MOUNTED IN THE HAZARDOUS AREA.
The system may be used with either zener safety barriers or
isolation safety barriers.
4 to 20 mA
Signal
HAZARDOUS
SAFE
TX6373.02
Group II sensor connections using zener safety barriers.
NB: IS EARTH MUST BE LESS THAN 10 OHMS LOOP RESISTANCE
Max. Cable Length: 1 km using 1.5 mm
2
cable conductors.
If you require any help with the use and connection of hazardous area equipment
please contact the Trolex Technical Department.
Signal Safety Barrier:
1 2 3 4 5 6 7 8
1
2
4
3
MTL 787S+
+V
+V
Signal
HAZARDOUS
SAFE
TX6373.02
Group II sensor connections using isolation safety barriers.
Max. Cable Length: 1 km using 1.5 mm
2
cable conductors.
Signal Isolation Barrier:
Pepperal & Fuchs
KFD2–CR–EX 1.30–300
1 2 3 4 5
Supply
6 7 8
1
2
8
7
3
11
12
KFD2–CR–EX 1.30–300
0V
+V
Signal
HAZARDOUS
SAFE
TX6373.02
LED sequence on power-
up Power up:
Red LED flashes 3 times
Normal Operation:
No LEDs illuminated
12/25
+V
0V
ISSUE N 06/15
