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General Environmental Considerations
Avoid installing the EZ12 unit in areas where the following conditions may exist:
•Environmental temperatures above or below those specified for the EZ12 unit
•Prolonged exposure to humidity and liquids which may be sprayed or splashed on the equipment
•Dusty environments where airborne particles may accumulate on equipment causing reduction of heat
dissipation and reduction in effective electrical spacing between components
•Areas with excessive vibration
•Areas with high-radiated electrical noise, such as near fields of transmitting antennas and areas in close
proximity of arc welding stations
Physical Layout in a Control Cabinet
When possible, cabinets housing electronic equipment should be designed with provisions for natural or forced
ventilation to facilitate heat dissipation. Observe the following rules for cabinet installation:
•Heat generating equipment (power supplies and other
heat inducing components) should be installed toward the
top of the cabinet. The lower space in the cabinet is
cooler than the top area.
•Install heat-sensitive components in the lower section.
•Provide enough space between components to allow a
free flow of air for better heat dissipation.
•Provide the maximum possible physical separation
between solid state and electromechanical controls. If
possible, the electromechanical controls (motors, starters,
solenoids, etc.) should be housed separately or at the
farthest point when enclosed within the cabinet.
We recommend that the unit has a minimum clear space of 2" on all sides for adequate ventilation as shown in the
image on the right.
Electrical Considerations
This section is designed to provide you with a very basic understanding of electrical noise and how to keep it away
from CPUs. Industrial plants have a number of generators of electrical noise that are sometimes also referred to as
Radio Frequency Interference (RFI). Anytime an inductive load like a motor, motor starter, or solenoid is turned off,
it generates a burst of excess energy that has to flow back to ground, just like electrical energy from a lightning
storm has to flow back to Earth. RFI is short bursts of electrical energy at very high frequencies. Other sources
include RF Welders or Radio Transmitters.
