Harsh Environments - Danfoss VLT Option Panel Instruction Manual

Harsh Environments

The mechanical and electrical components within
the option 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.
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 NEMA 12 enclosures to
limit the exchange of outside air into the option
enclosure. Extremely harsh environments may
require a higher level of protection.
Airborne Solids
Particles in the air may cause mechanical,
electrical or thermal failure in components. A NEMA
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. A typical indicator of excessive levels of
airborne particles is dust around the fan. In dusty
environments, use NEMA 12 enclosures.
12
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.