HP L1000 - 9000 - 0 MB RAM, User Manual

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Appendix C
General Site Preparation Guidelines
Electrical Factors
196
Raised Floor “High Frequency Noise” Grounding
If a raised floor system is used, install a complete signal grounding grid for maintaining equal potential over
a broad band of frequencies. The grounding grid should be connected to the equipment cabinet and electrical
service entrance ground at multiple connection points using a minimum #6 AWG (16mm2) wire ground
conductor. The following figure illustrates a metallic strip grounding system.
Hewlett-Packard recommends the following approaches:
• Excellent—Add a grounding grid to the subfloor. The grounding grid should be made of copper strips
mounted to the subfloor. The strips should be 0.032 in. (0.08 cm) thick and a minimum of 3.0 in. (8.0 cm)
wide.
Connect each pedestal to four strips using 1/4 in. (6.0 mm) bolts tightened to the manufacturer’s torque
recommendation.
• Better - A grounded #6 AWG minimum copper wire grid mechanically clamped to floor pedestals and
properly bonded to the building/site ground.
• Good—Use the raised floor structure as a ground grid. In this case, the floor must be designed as a ground
grid with bolted down stringers and corrosion resistive plating (to provide low resistance and attachment
points for connection to service entrance ground and hp computer equipment). The use of conductive floor
tiles with this style of grid further enhances ground performance.
Figure C-1 Raised Floor Metal Strip Ground System
Ground wire
to power panel
Grounding clamp
Band and pedestal Grounding braid
to computer equipment
Grounding grid element
Hex bolt
Floor panel
11/30/99
60SP010A