Emc Considerations; Cabling - Honeywell Vertex Operating Manual

EMC Considerations

Your Honeywell Analytics continuous gas monitor
has been designed to comply with applicable
Electromagnetic Compatibility (EMC) standards
at the time of manufacture. The design includes
filtering, shielding and bypassing techniques. At
the time of certification, simulated customer Input/
Output (I/O) schemes were tested.
All methods used in your equipment for emission
suppression and reduction of susceptibility are
interactive. Modifications to the monitor could result
in increased emissions and higher vulnerability to
other radiated fields.
Following the guidelines in this EMC Considerations
section will ensure your monitor maintains the
highest degree of EMC integrity. The guidelines
listed apply only to I/O emissions and do not apply
to A.C. and D.C. monitor power connections.

Cabling

At a very minimum, all cables should include a
braided shield. Ideal results have been obtained
with twisted pair cabling which has a foil shield
surrounding each pair plus foil and 90% braid
shielding around the bundle. In addition, ensure
local electrical code requirements are met.
Vertex Technical Handbook
V
ertex 72-Point Continuous Monitor
TM
The following cable parameters must be
considered:
Braid
Foil
Twisted Pair
Stranded Pair
Shield
Termination
Note:
Honeywell Analytics product testing uses >90%
braid with foil (around the bundle); twisted
pair; stranded 24 AWG (minimum wiring for all
qualification and certification testing.)
ii
Must have a minimum 90%
coverage
When used with braid, provides
100% coverage
Do not use foil alone. It has a
tendency to break.
Provides for cancelling of
magnetic fields
Provides the greatest surface
area
Continuation of the shield to the
cabinet earth ground is most
important.
For discrete wire terminations,
pigtails to the cabinet (connector)
ground should be extremely short
(absolutely no greater than three
inches).
For multiconductor connector
terminations, only 360° shielded
shells should be used.