Ametek Dycor CG1000-RTP User Manual page 8

Electromagnetic Compatibility (EMC)
The various configurations of the CG1000-RTP 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 that certain installation techniques
and wiring practices are used to prevent or minimize erratic behavior of the Ana-
lyzer or its electronic neighbors. 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 otherwise 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 equip-
ment 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. Discon-
necting one shield ground may not provide sufficient protection depending on the
electronic environment. 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 so that the shield materials
can be wrapped backwards onto the cable jacket and captured inside the gland, and
tightened up against the metal interior.
Inductive loads connected to the low voltage "Alarm Contacts" are not recommend-
ed. However, if this becomes a necessity, adhere to proper techniques and wiring
practices. 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 using an additional cable shield on the offending cable.
In general, for optimum protection against high frequency transients and other dis-
turbances, do not allow installation of this Analyzer where its unshieled I/O and DC
circuits are physically mixed with AC mains or any other circuit that could induce
viii | Dycor CG1000-RTP Oxygen Analyzer
Read and follow the recommendations in this section to avoid performance
variations or damage to the internal circuits of this equipment when installed
in harsh electrical environments.