Emerson 2400S Manuel D’Utilisation
Installation Manual
23
I/O Wiring – Model 2400S Analog Transmitters
P
o
wer Su
ppl
y
I/O
W
irin
g
W
irin
g
– DP
an
d
d
DN
I/
O W
iri
n
g
– AN
Be
fo
fo
re
Y
Y
o
u
Begin
Figure 3-16
Safe area mA output load resistance values
3.5.3
Hazardous area frequency/discrete output wiring
The following frequency/discrete output wiring diagrams are examples of proper hazardous area
wiring for the transmitter’s frequency/discrete output:
wiring for the transmitter’s frequency/discrete output:
•
The diagram in Figure 3-17 utilizes a galvanic isolator that has an internal 1000 Ohm resistor
used for sensing current:
used for sensing current:
-
ON > 2.1 mA
-
OFF < 1.2 mA
•
The diagram in Figure 3-18 utilizes a barrier with external load resistance.
0
200
400
600
800
1000
1200
1400
0
4
8
12
16
20
24
28
32
36
Supply voltage VDC (Volts)
Exter
nal
resistor
R
load
+ R
ba
rr
ie
r
(Ohm
s)
R
max
= (Vsupply – 4)/0.022
If communicating with HART, a minimum of 250 Ohms and 17.5 V is required
OPERATING REGION