VEGA VEGASON 66 Foundation Fieldbus - Manual (Page 24)

5 Connecting to voltage supply
5.1 Preparing the connection
Generally not the following safety instructions:
l
Connect only in the complete absence of line voltage
l
If overvoltage surges are expected, overvoltage arresters
should be installed according to Foundation Fieldbus
specification.
In hazardous areas you should take note of the appropriate
regulations, conformity and type approval certificates of the
sensors and power supply units.
VEGASON 66 requires a supply voltage of 9 … 32 V DC.
Power and the digital bus signal are carried on the same two-
wire connection cable. Power is supplied via the H1 power
supply.
VEGASON 66 is connected with screened cable according to
the Fieldbus specification. An outer cable diameter of 5 … 9 mm
ensures the seal effect of the cable gland.
Please make sure that your entire installation is carried out
according to the Fieldbus specification. In particular, make
sure that the termination of the bus is done with appropriate
terminating resistors.
On VEGASON 66 with cable gland ½ NPT and plastic housing,
a metal ½" threaded insert is moulded in the plastic housing.
Caution:
No grease should be used when screwing the NPT cable
gland or steel tube into the threaded insert. Standard grease
can contain additives affecting the connection between
threaded insert and housing. This will influence the stability of
the connection and the tightness of the housing.
In 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. The screen in the sensor
must be connected directly to the internal ground terminal. The
ground terminal outside on the housing must be connected to
the potential equalisation (low impedance).
Note safety instructions
Take note of safety
instructions for Ex
applications
Select power supply
Selecting the connection ca-
ble
Cable gland ½ NPT
Cable screening and ground-
ing
24 VEGASON 66 - Foundation Fieldbus
Connecting to voltage supply
28795
-EN
-060731