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 voltage surges are expected
,
install overvoltage arresters
T
he instrument requires a operating voltage of
9
…
32
V DC
.
O
perating voltage 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 a di
ff
erent diameter or cross
-
section
,
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 bus is
terminated with suitable terminating resistors
.
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
"
I
n the case of instrument housings with self
-
sealing
NPT
threads
,
it is
generally not possible to have the cable glands screwed in at the
factory
.
T
he openings for the cable glands are therefore covered with
red protective caps as transport protection
.
Y
ou have to replace these protective caps with approved cable glands
before setup or cover them with suitable
fi
ller plugs
.
U
nused cable
glands do not provide su
ffi
cient protection against moisture and must
be replaced with
fi
ller plugs
.
T
he suitable cable glands and blind plugs come with the instrument
.
M
ake sure that the cable screening and ground is executed according
to the
F
ielbus speci
fi
cation
.
I
f electromagnetic interference is expected
which is above the test values of
EN
61326
-
1
for industrial areas
,
we
recommend to connect the cable screen on both ends to ground
potential
.
W
ith systems with potential equalisation
,
connect the cable screen
directly to ground potential at the power supply unit
,
in the connection
box and at the sensor
.
T
he screen in the sensor must be connected
directly to the internal ground terminal
.
T
he ground terminal outside on
the housing must be connected to the potential equalisation
(
low
impedance
).
S
afety instructions
V
oltage supply
C
onnection cable
C
able gland
½
NPT
C
able screening and
grounding
16
POINTRAC
31
•
F
oundation
F
ieldbus
5
C
onnecting to power supply
41779
-
EN
-
120329
