5
C
onnecting to power supply
5
.
1
P
reparing the connection
A
lways keep in mind the following safety instructions
:
l
C
onnect only in the complete absence of line voltage
l
I
f overvoltages are expected
,
install overvoltage arresters
P
ower supply and current signal are carried on the same two
-
wire
cable
.
T
he voltage supply range can di
ff
er depending on the
instrument version
.
T
he data for power supply are speci
fi
ed in chapter
"
T
echnical data
"
.
P
rovide a reliable separation between the supply circuit and the mains
circuits according to
DIN VDE
0106
part
101
.
K
eep in mind the following additional in
fl
uences on the operating
voltage
:
l
O
utput voltage of the power supply unit can be lower under
nominal load
(
with a sensor current of
20
.
5
m
A
or
22
m
A
in case of
fault message
)
l
I
n
fl
uence of additional instruments in the circuit
(
see load values in
chapter
"
T
echnical data
"
)
T
he signal conditioning instruments
VEGAMET
and
VEGASCAN
have
digital sensor recognition
.
W
hen connecting
VEGAPULS
62
,
an up
-
to
-
date software version of the signal conditioning instrument is required
for the signal conditioning instrument
.
F
or a software update go to
"
S
oftware
"
under
"
www
.
vega
.
com
/
downloads
"
.
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
for industrial areas
,
screened cable should be
used
.
U
se cable with round cross
-
section
.
A
cable outer diameter of
5
…
9
mm
(
0
.
2
…
0
.
35
in
)
ensures the seal e
ff
ect of the cable gland
.
I
f you are
using cable with a di
ff
erent diameter or cross
-
section
,
exchange the
seal or use a suitable cable gland
.
W
e generally recommend the use of screened cable for
HART
multidrop mode
.
W
ith plastic housing
,
the
NPT
cable gland or the
C
onduit steel tube
must be screwed without grease into the threaded insert
.
M
ax
.
torque for all housings see chapter
"
T
echnical data
"
S
afety instructions
V
oltage supply
C
onnection to signal
conditioning instru
-
ments
C
onnection cable
C
able gland
½
NPT
VEGAPULS
62
•
4
…
20
m
A
/
HART
two
-
wire
25
5
C
onnecting to power supply
36503
-
EN
-
100607