IBM LCM8, Installation And User Manual

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Appendixes 61
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Particulate contamination
Attention: Airborne particulates (including metal flakes or particles) and reactive gases acting
alone or in combination with other environmental factors such as humidity or temperature might
pose a risk to the device that is described in this document. Risks that are posed by the presence of
excessive particulate levels or concentrations of harmful gases include damage that might cause the
device to malfunction or cease functioning altogether. This specification sets forth limits for partic-
ulates and gases that are intended to avoid such damage. The limits must not be viewed or used as
definitive limits, because numerous other factors, such as temperature or moisture content of the
air, can influence the impact of particulates or environmental corrosives and gaseous contaminant
transfer. In the absence of specific limits that are set forth in this document, you must implement
practices that maintain particulate and gas levels that are consistent with the protection of human
health and safety. If IBM determines that the levels of particulates or gases in your environment
have caused damage to the device, IBM may condition provision of repair or replacement of
devices or parts on implementation of appropriate remedial measures to mitigate such environmen-
tal contamination. Implementation of such remedial measures is a customer responsibility.
Table H.2: Limits for particulates and gases
Contaminant Limits
Particulate
•
The room air must be continuously filtered with 40%
atmospheric dust spot efficiency (MERV 9) according
to ASHRAE Standard 52.2
1
.
• Air that enters a data center must be filtered to
99.97% efficiency or greater, using high-efficiency
particulate air (HEPA) filters that meet MIL-STD-282.
• The deliquescent relative humidity of the particulate
contamination must be more than 60%
2
.
• The room must be free of conductive contamination
such as zinc whiskers.
Gaseous
• Copper: Class G1 as per ANSI/ISA 71.04-1985
3
• Silver: Corrosion rate of less than 300 Å in 30 days
1
ASHRAE 52.2-2008 - Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by
Particle Size . Atlanta: American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
2
The deliquescent relative humidity of particulate contamination is the relative humidity at which the dust
absorbs enough water to become wet and promote ionic conduction.
3
ANSI/ISA-71.04-1985. Environmental conditions for process measurement and control systems: Airborne
contaminants. Instrument Society of America, Research Triangle Park, North Carolina, U.S.A.