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 overvoltage surges are expected
,
overvoltage arresters
should be installed according to
F
oundation
F
ieldbus
speci
fi
cation
T
ip
:
W
e recommend
VEGA
overvoltage arrester
B
63
-
32
.
I
n hazardous areas you should take note of the appropriate
regulations
,
conformity and type approval certi
fi
cates of the
sensors and power supply units
.
T
he instrument requires a supply voltage of
9
…
32
V DC
.
P
ower and the digital bus signal are carried on the same two
-
wire connection cable
.
P
ower is supplied via the
H
1
power
supply
.
C
onnection is carried out with screened cable according to
F
ieldbus speci
fi
cation
.
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 other diameter or cross
-
section
,
you have to exchange the seal or use a suitable cable
gland
.
M
ake sure that the entire installation is carried out according to
the
F
ieldbus speci
fi
cation
.
I
n particular
,
make sure that the
termination of the bus is done with appropriate terminating
resistors
.
O
n the instrument with cable entry
½
NPT
and plastic housing
there is a metallic
½"
threaded insert moulded into the plastic
housing
.
C
aution
:
N
o grease should be used when screwing the
NPT
cable
gland or steel tube into the threaded insert
.
S
tandard grease
can contain additives that corrode the connection between
threaded insert and housing
.
T
his would in
fl
uence the stability
of the connection and the tightness of the housing
.
N
ote safety instructions
T
ake note of
safety instruc
-
tions for
E
x ap
-
plications
S
elect power supply
S
electing connection
cable
C
able gland
½
NPT
14
VEGAFLEX
65
•
F
oundation
F
ieldbus
5
C
onnecting to power supply
31848
-
EN
-
080716
