12
FC-21 Flow Computer
4.3 Wiring In Hazardous Areas:
Examples using Barrier (MTL4755ac for RTD)
1
2
3
4
4-20
Q/
∆
P
+
–
2 1
3 4
28V
Diode
24V Out
4-20mA In
Common
4-20mA Flow
Transmitter
Hazardous Area
Safe Area
Flow Input
Flow Input
Hazardous Area
Safe Area
Temperature Input
(4-20mA Transmitter)
4-20
T
–
+
1 2
4 3
28V
Diode
1
4
8
24V Out
4-20mA Temp.
Transmitter
4-20mA In
Common
Temperature Input
(4-20mA Transmitter)
Hazardous Area
Safe Area
Temperature Input
(RTD)
4
5
6
7
8
1 2 3 4 5 6
7 8 9 10 1
1
12 13 14 15 16 17
Common
RTD Excite (+)
RTD Sense (+)
RTD Sense (–)
3-Wire RTD
Temperature Input
(RTD)
