Output Wiring – Model 1700/2700 Intrinsically Safe Transmitters
5.4.2
Hazardous area mA output wiring
Figure 5-7 provides an example of basic hazardous area wiring for the Model 1700 transmitter's mA
output or the Model 2700 transmitter's primary mA output.
Figure 5-7
Hazardous area mA output wiring
Hazardous area
5.4.3
Hazardous area frequency/discrete output wiring
The following frequency/discrete output wiring diagrams are examples of proper hazardous area
wiring for the Model 1700 transmitter's frequency output or the Model 2700 transmitter's
frequency/discrete output:
The diagram in Figure 5-8 utilizes a galvanic isolator that has an internal 1000 Ω resistor used
•
for sensing current:
-
ON > 2.1 mA
-
OFF < 1.2 mA
•
The diagram in Figure 5-9 utilizes a barrier with external load resistance.
Installation Manual
Safe area
R
barrier
Note: R
and R
should be added together to
barrier
load
determine the proper V
. Refer to Figure 5-2.
in
V
in
V
out
R
4-20 mA
load
Ground
39