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Emerson Process Management GmbH & Co. OHG4-32
X-STREAM XE
Instruction Manual
HASXEE-IM-HS
04/2010
On-site conditions often differ from test
environments and may require special pre-
cautions. Such a case arises when strong
electromagnetic elds which could induce
an interference current in the shielding. This
type of current creates a potential difference
between the connected housings.
Two possible methods of eliminating this are
described here. Fitters familiar with EMC
problems must decide which method should
be emplyed.
• The shielding is connected only at one
end (connecting to the analyzer is re-
commended): this gives better protection
against external interference, and inter-
ference currents are prevented because
the ground loop is interrupted.
This is the preferred method for connecting
cable shields in hazardous area installations,
to prevent interference currents between con-
nected enclosures.
• Cables with double shielding: in this
case, one shielding is connected to the
analyzer housing, the other shielding
to the external device. This is advan-
tageous when both units are supplied
from different grids (e.g. when installed
in different buildings).
This method is more expensive, but gi-
ves the best protection against external
interference and against interference
currents
.
Fig. 4-25: Shielded Signal Cable, Shielding Connected At One end.
Fig. 4-26: Signal Cable With Double Shielding, Shieldings Connected At Alternate Ends.
4.6 Installation - Notes on Wiring