8
E
lectronics
-
4
…
20
m
A
/
HART
-
two
-
wire
C
on
fi
guration of the electronics
T
he pluggable electronics is mounted in the electronics compartment of
the instrument and can be exchanged by the user when servicing is re
-
quired
.
T
he electronics is completely encapsulated to protect against
vibration and moisture
.
T
he terminals for voltage supply as well as the contact pins with
I
²
C
inter
-
face for parameter adjustment are located on the upper side of the elec
-
tronics
.
I
n the double
-
chamber housing
,
the terminals are located in the
separate terminal compartment
.
V
oltage supply
P
ower supply and current signal are carried on the same two
-
wire cable
.
T
he operating voltage can di
ff
er depending on the instrument version
.
Y
ou can
fi
nd the data of the voltage supply in chapter
"
T
echnical data
"
in
the operating instructions manual of the respective instrument
.
P
rovide a reliable separation between the supply circuit and the mains
circuits according to
DIN EN
61140
VDE
0140
-
1
.
D
ata of the voltage supply
:
l
O
perating voltage
-
9
.
6
…
35
V DC
l
P
ermissible residual ripple
-
N
on
-
E
x
,
E
x
-
ia instrument
-
for
U
N
12
V DC
:
≤
0
.
7
V
e
ff
(
16
…
400
H
z
)
-
for
U
N
24
V DC
:
≤
1
.
0
V
e
ff
(
16
…
400
H
z
)
l
P
ermissible residual ripple
-
E
x
-
d
-
ia instrument
-
for
U
N
24
V DC
:
≤
1
.
0
V
e
ff
(
16
…
400
H
z
)
K
eep in mind the following additional factors that in
fl
uence the operating
voltage
:
l
L
ower output voltage of the power supply unit under nominal load
(
e
.
g
.
with a sensor current of
20
.
5
m
A
or
22
m
A
in case of fault
)
l
I
n
fl
uence of additional instruments in the circuit
(
see load values in
chapter
"
T
echnical data
"
of the operating instructions of the respective
instrument
)
C
onnection cable
T
he instrument is connected with standard two
-
wire cable without screen
.
I
f electromagnetic interference is expected which is above the test values
of
EN
61326
-
1
for industrial areas
,
screened cable should be used
.
I
n the product con
fi
gurator of
VEGABAR
,
di
ff
erent cable glands are avail
-
able
.
T
his selection covers all cable diameters in the range of
4
…
12
mm
(
0
.
16
…
0
.
47
in
).
W
e generally recommend the use of screened cable for
HART
multidrop
mode
.
C
able screening and grounding
I
f screened cable is required
,
we recommend connecting the cable
screen on both ends to ground potential
.
I
n the sensor
,
the screen must
be connected directly to the internal ground terminal
.
T
he ground terminal
on the outside of the housing must be connected to the ground potential
(
low impedance
).
C
onnection
S
ingle chamber housing
5
1
2
+
( )
(-)
6
7
8
4...20mA
2
3
4
1
F
ig
.
25
:
E
lectronics and terminal compartment
,
single chamber housing
1
V
oltage supply
/
S
ignal output
2
F
or display and adjustment module or interface adapter
3
F
or external display and adjustment unit
4
G
round terminal for connection of the cable screen
D
ouble chamber housing
4...20mA
2
3
1
2
+
( )
(-)
1
F
ig
.
26
:
T
erminal compartment
,
double chamber housing
1
V
oltage supply
/
S
ignal output
2
F
or display and adjustment module or interface adapter
3
G
round terminal for connection of the cable screen
E
lectronics
-
4
…
20
m
A
/
HART
-
two
-
wire
10
P
rocess pressure
–
P
ressure transmitter
45078
-
EN
-
140625
