Dust And Pollution Control; Metal Particulate Contamination - HP Cluster Platform Introduction v2010 Introduction Manual

Low humidity contributes to undesirably high levels of electrostatic charges. This increases the
electrostatic discharge (ESD) voltage potential. ESD can cause component damage during servicing
operations. Low humidity levels are often the result of the facility heating system and occur
during the cold season. Most heating systems cause air to have a low humidity level, unless the
system has a built-in humidifier.
C.2.2.5 Dust and Pollution Control
Computer equipment can be adversely affected by dust and microscopic particles in the site
environment.
Specifically, disk drives, tape drives, and some other mechanical devices can have bearing failures
that result from airborne abrasive particles. Dust might also blanket electronic components such
as printed circuit boards causing premature failure due to excess heat and humidity. Other
failures to power supplies and other electronic components can be caused by metallically
conductive particles. These metallic particles are conductive and can short-circuit electronic
components. Make every effort to ensure that the environment is as dust and particle free as
possible.
Smaller particles can pass though some filters and, over a period of time, possibly cause problems
in mechanical parts. Small dust particles can be prevented from entering the computer room by
maintaining its air conditioning system at a high static air pressure level.
C.2.3 Metal Particulate Contamination
Metallic particulates can be especially harmful around electronic equipment. This type of
contamination might enter the data center environment from a variety of sources, including (but
not limited to) raised floor tiles, worn air conditioning parts, heating ducts, rotor brushes in
vacuum cleaners, or printer component wear. Because metallic particulates conduct electricity,
they have an increased potential for creating short circuits in electronic equipment. This problem
is exaggerated by the increasingly dense circuitry of electronic equipment.
Over time, very fine whiskers of pure metal can form on electroplated zinc, cadmium, or tin
surfaces. If these whiskers are disturbed, they may break off and become airborne, possibly
causing failures or operational interruptions. For more than 50 years, the electronics industry
has been aware of the relatively rare but possible threat posed by metallic particulate
contamination. During recent years, a growing concern has developed in computer rooms where
these conductive contaminants are formed on the bottom of some raised floor tiles.
Although this problem is relatively rare, it might be an issue within your computer room. Since
metallic contamination can cause permanent or intermittent failures on your electronic equipment,
Hewlett-Packard strongly recommends that your site be evaluated for metallic particulate
contamination before installation.
C.2 Environment 55