IBM 2810-A14, Manual

Page: 31 / 62

The following criteria must be met:
Gaseous contamination
Severity level G1 as per ANSI/ISA 71.04-1985
1
, which states that the
reactivity rate of copper coupons shall be less than 300 Angstroms per
month (Å/month,
≈ 0.0039 µg/cm2-hour weight gain)
2
. In addition, the
reactivity rate of silver coupons shall be less than 300Å/month ( ≈ 0.0035
µg/cm2-hour weight gain)
3
. The reactive monitoring of gaseous corrosivity
should be conducted approximately 2 inches (5 cm) in front of the rack on
the air inlet side at one-quarter and three-quarter frame height off the floor,
or where the air velocity is much higher.
Particulate contamination
Data centers must meet the cleanliness level of ISO 14644-1 class 8. For
data centers without airside economizers, the ISO 14644-1 class 8
cleanliness can be met by choosing one of the following filtration methods:
v The room air can be continuously filtered with MERV 8 filters.
v
Air entering a data center can be filtered with MERV 11, or preferably
MERV 13 filters.
For data centers with airside economizers, the choice of filters to achieve
ISO class 8 cleanliness depends on the specific conditions present at that
data center. The deliquescent relative humidity of the particulate
contamination should be more than 60% RH
4
. Data centers must be free of
zinc whiskers
5
.
1.
ANSI/ISA-71.04.1985. Environmental conditions for process measurement and control
systems: Airborne contaminants. Instrument Society of America, Research Triangle
Park, NC, 1985.
2. The derivation of the equivalence between the rate of copper corrosion product
thickness growth in Å/month and the rate of weight gain assumes that Cu
2
S
and Cu
2
O grow in equal proportions.
3. The derivation of the equivalence between the rate of silver corrosion product
thickness growth in Å/month and the rate of weight gain assumes that Ag
2
S is
the only corrosion product.
4. The deliquescent relative humidity of particulate contamination is the relative
humidity at which the dust absorbs enough water to become wet and promote
corrosion, ion migration, or both.
5. Surface debris is randomly collected from 10 areas of the data center on a 1.5
cm diameter disk of sticky, electrically conductive tape on a metal stub. If
examination of the sticky tape in a scanning electron microscope reveals no zinc
whiskers, the data center is considered free of zinc whiskers.
Physical space requirements
Depending upon shipment dates, racks are supplied with one of the following
front doors:
v
Doors supplied with racks ordered with feature code 1100; See Appendix D,
“Specifications - pre-August, 2009 racks,” on page 27 for the dimensions of racks
ordered with feature code 1100.
v
Doors supplied with racks ordered with feature code 1101 (door includes an IBM
logo illuminated by an LED); Dimensions for IBM XIV systems ordered with
feature code 1101 are shown in Table 9 on page 12.
Chapter 3. Physical requirements
11
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