dirt. If the unit does not have power applied to it,
supply a protective covering. It is important to
ensure that the components stay as clean as
possible. It may be necessary to clean the interior
once construction is completed.
•
Keep drawings and manuals accessible for
detailed installation and operation instructions. It
is important that the manuals be available for
equipment operators.
2.2 Harsh Environments
The mechanical and electrical components within the
panel can be adversely affected by the environment. The
effects of contaminants in the air, either solid, liquid, or
gas, are difficult to quantify and control.
2.2.1 Airborne Liquids
Liquids in the air can condense in components. Water
carried in the air is easily measured as relative humidity,
but other vapors are often more difficult to measure or
control. Steam, oil and salt water vapor may cause
corrosion of components. In such environments, use TYPE
12 enclosures to limit the exchange of outside air into the
option enclosure. Extremely harsh environments may
require a higher level of protection.
2.2.2 Airborne Solids
Particles in the air may cause mechanical, electrical or
thermal failure in components. A TYPE 1 enclosure
provides a reasonable degree of protection against falling
particles, but it will not prevent the fan from pulling dirty
air into the enclosure.
2.2.3 Corrosive Chemicals
In environments with high temperatures and humidity,
corrosive gases
such as sulfur, nitrogen and chlorine
compounds cause corrosion to occur in components.
Indications of corrosion are blackened copper or rust on
steel or oxidized aluminum. In such environments, it is
recommended that the equipment be mounted in a
cabinet with fresh air ventilation and that corrosive
compounds be kept away. A non-ventilated cabinet fitted
with an air conditioner as a heat exchanger may be used.
Conformal coated circuit boards may be specified to
reduce the corrosive effects of a harsh environment.
Pre-installation
Vertical Bypass/Non Bypass Panel
2-2
MG.13.A1.22 - VLT
®
is a registered Danfoss trademark
2
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