Emerson FOUNDATION Fieldbus Interface Bedienungsanleitung Seite 8

Safe Use Instructions – F
Figure 10. Integral Wiring of the FFI
Wiring the FFI as a Standalone Device
If you choose to configure the FFI as a standalone unit
separate from a ROC800, you must wire the FFI to its
own power supply. See Figure 11.
Figure 11. Standalone Wiring of the FFI
GROUNDING THE FFI
If your company has no specific grounding
requirements, install the FFI as a "floating"
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Fieldbus Interface
(unconnected to ground) system. Otherwise, follow
your company's specific grounding practices.
However, if you are making a connection between a
grounded device and a FFI EIA-485 (RS-485) port,
ground the FFI power supply.
If you must ground the equipment, observe the
following guidelines:
•
When the equipment uses a DC voltage source,
the grounding system must terminate at the
service disconnect. All equipment grounding
conductors–including wire or conduit carrying
the power supply conductors–must provide an
uninterrupted electrical path to the service
disconnect.
•
Improper grounding or poor grounding practices
can often cause problems, such as introducing
ground loops into the system. Properly
grounding the FFI helps to reduce the effects of
electrical noise on the unit's operation and
protects against lightning. Install a surge
protection device at the service disconnect on
DC voltage source systems to protect the
installed equipment against lightning and power
surges. You may also consider a telephone
surge protector for the dial-up modem
communications module.
Connect the power wiring. Determine the power
requirements as described in Chapter 3 of the
Foundation Fieldbus Interface Instruction Manual
(Form A6259).
Verifying the Connection Polarity
1. To make DC power supply connections:
•
If appropriate, perform the backup
configuration and log data procedure.
•
Optionally, install a surge protection device at
the service disconnect.
•
Remove all other power sources from the
ROC800.
•
Install a fuse at the input power source.
•
Remove the terminal block connector from
the socket.
•
Insert the bared end of each wire into either
the clamp beneath the appropriate BAT+ /
BAT– termination screw (for the 12-volt dc
source) OR into the clamp beneath the
appropriate + / - termination screw (for the
24-volt dc source).
Note: The + terminal should also have a
fuse.
Form A6296
Page 6