Electromagnetic Compatibility - Ametek 3050-AP User Manual

Electromagnetic Compatibility (EMC)
READ AND FOLLOW THE RECOMMENDATIONS IN THIS SECTION IN
!
ORDER TO AVOID PERFORMANCE VARIATIONS OR DAMAGE TO THE
INTERNAL CIRCUITS OF THIS EQUIPMENT WHEN INSTALLED IN HARSH
CAUTION
ELECTRICAL ENVIRONMENTS.
The various configurations of the 3050-AP should not produce, or fall victim to, electromagnetic
disturbances as specified in the European Union's EMC Directive. Strict compliance to the
EMC Directive requires certain installation techniques and wiring practices be used in order
that erratic behavior of the Analyzer, or its electronic neighbors be prevented or minimized.
Below are examples of the techniques and wiring practices to be followed:
In meeting the EMC requirements, the various Analyzer configurations described in this manual
rely heavily on the use of metallic shielded cables used to connect to the customer's equipment
and power. Foil and braid shielded I/O and DC power cables are recommended for use in oth-
erwise unprotected situations. In addition, hard conduit, flexible conduit, and armor around
non-shielded wiring also provides excellent control of radio frequency disturbances. However,
use of these shielding techniques is effective only when the shielding element is connected
to the equipment chassis/earth ground at both ends of the cable run. This may cause ground
loop problems in some cases. These should be treated on a case-by-case basis. Disconnecting
one shield ground may not provide sufficient protection depending on the electronic envi-
ronment. Connecting one shield ground via a 0.1 microfarad ceramic capacitor is a technique
allowing high frequency shield bonding while avoiding the AC ground, metal connection. In
the case of shielded cables, the drain wire or braid connection must be kept short. A two inch
connection distance between the shield's end, and the nearest grounded chassis point, ground
bar or terminal is highly recommended. An even greater degree of shield performance can
be achieved by using metallic glands for shielded cable entry into metal enclosures. Expose
enough of the braid/foil/drain where it passes through the gland such that the shield materials
can be wrapped backwards onto the cable jacket and captured inside the gland, tightened up
against the metal interior.
Inductive loads connected to the low voltage "Alarm Contacts" is not recommended. However,
if this becomes a necessity, proper techniques and wiring practices must be adhered to. Install
an appropriate transient voltage suppression device (low voltage MOV, "Transzorb", or R/C)
as close as possible to the inductive device to reduce the generation of transients. Do not run
this type of signal wiring along with other I/O or DC in the same shielded cable. Inductive
load wiring must be separated from other circuits in conduit by the use of an additional cable
shield on the offending cable.
In general, for optimum protection against high frequency transients and other disturbances,
do not allow installation of this Analyzer whereby its unshieled I/O and DC circuits are physi-
cally mixed with AC mains, or any other circuit that could induce transients into the Analyzer
or the overall system. Examples of electrical events and devices known for the generation of
harmful electromagnetic disturbances include motors, capacitor bank switching, storm related
transients, RF welding equipment, static, and walkie-talkies.
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