General Site Preparation Guidelines
Environmental Elements
Chapter 2
24
Although this problem is relatively rare, it may 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 of
electronic equipment.
ESD Prevention
Static charges (voltage levels) occur when objects are separated or rubbed together. The voltage level of a
static charge is determined by the following factors:
•
Types of materials
•
Relative humidity
•
Rate of change or separation
Static Protection Measures
Follow these precautions to minimize possible ESD-induced failures in the computer room:
•
Maintain recommended humidity level and airflow rates in the computer room.
•
Install conductive flooring (conductive adhesive must be used when laying tiles).
•
Use conductive wax if waxed floors are necessary.
•
Ensure that all equipment and flooring are properly grounded and are at the same ground potential.
•
Use conductive tables and chairs.
•
Use a grounded wrist strap (or other grounding method) when handling circuit boards.
•
Store spare electronic modules in antistatic containers.
Acoustics
Computer equipment and air conditioning blowers cause computer rooms to be noisy. Ambient noise level in a
computer room can be reduced as follows:
Table 2-1
Effect of Humidity on ESD Charge Levels
Personnel Activity
a
a. Source: B.A. Unger, Electrostatic Discharge Failures of Semiconductor Devices
(Bell Laboratories, 1981)
Humidity
b
and Charge Levels (voltages)
c
b. For the same relative humidity level, a high rate of airflow produces higher
static charges than a low airflow rate.
c. Some data in this table has been extrapolated.
26%
32%
40%
50%
Person walking across a linoleum
floor
6,150 V
5,750 V
4,625 V
3,700 V
Person walking across a carpeted
floor
18,450 V
17,250 V
13,875 V
11,100 V
Person getting up from a plastic
chair
24,600 V
23,000 V
18,500 V
14,800 V
Summary of Contents for Integrity rx5670
Page 4: ...Contents 4 Power Cable 43 Glossary 45 ...
Page 10: ...System Specifications Environmental Specifications Chapter 1 10 ...
Page 30: ...General Site Preparation Guidelines Space Requirements Chapter 2 30 Equipment cable routing ...
Page 42: ...Power Plug Configuration Male End of Power Cable Chapter 3 42 Figure 3 10 GB 1002 Plug ...
Page 44: ...Power Plug Configuration Power Cable Chapter 3 44 ...
