ENVIRO-SHIELD
"3 Levels of Environmental Protection"
For years, a major problem in the electronic
industry has been the deterioration of electrical components from
the natural elements such as rain, sleet, and snow. Other conditions
such as salt from coastal areas or road salts cause accelerated
corrosion on electrical components. Even sulfur dioxide produced
from the burning of coal has a major impact on electrical component
life. Cooling fans are no exception to this rule.
Comair Rotron, the leader in innovative cooling ideas, has pioneered
the way in environmentally protected fans. With the continuous
advancements in conformal coating materials, Comair Rotron has
researched various chemicals, materials, and processes that provide
the greatest degree of protection to our customers. The results
have produced our latest value-added product, "Enviro-Shield".
The Enviro-Shield products are rated to 3 levels of protection;
which are described later in this paper as Type 1, 2, & 3. Each
material fully encompasses all electrical components, wires, circuit
paths, motor windings, and stator assemblies; ensuring the optimum
protection for any condition. These materials can be sprayed,
dipped, or injected into the motor assemblies, creating a protective
barrier between the delicate electrical components and the outside
environments.
Comair Rotron's environmentally protected fans are designed and
tested to withstand mild environmental conditions such as light
water mists to the harshest environments including long term salt
exposure. There are several standard specifications written with
various degrees of protection and methods for testing to these
standards. The most common standards are NEMA, IP, BELCOR, MIL,
UL, and ASTM. These standards and the testing methods can be made
available to you upon request.
To test a fan's ability to maintain such reliable protection,
Comair uses a variety of testing apparatus. The most commonly
refer to test is the salt fog test. This test demands that the
fan be subjected to as many as 14 days of continuous exposure
to salt fog environment. Types 2 and 3 materials have gone as
high as 80+ days before encountering a failure. This says a lot
considering 14 days is estimated as the equivalent to 10 years
of normal operation. Other tests include direct water spraying
on the fan, humidity, and dust.
Some discussion can be made over the type of bearing used. Comair
has performed numerous tests and has found that the ball bearing
system works exceptionally well. It is not recommended to use
sleeve bearings in an environmentally protected fan. The ball
bearings are double shielded which resists most contaminants from
entering the bearing surfaces.
As a brief outline as to what type of protection is best suited
for your needs, consider the following:
1. Type 1 protection is intended for environments that included
exposure to water mists, sprays, dripping, dust, condensation,
and moderate vibrations.
2. Type 2 protection is intended for harsher environments that
include exposure to ocean salts in the form of fog or a mist.
Type 2 protection also provides extra protection to the fan for
excessive shock and vibration.
3. Type 3 protection is also intended for harsh salt fog environments
but includes additional protection to the motor windings. Type
3 protection also provides extra protection to the fan for excessive
shock and vibration.
