Building Distribution; Grounding Systems; Power Distribution Safety Grounding (Lahj); Main Building Electrical Ground - HP 9000 rp3410 Manual

Building Distribution

Place building feeders and branch circuitry in rigid metallic conduits with proper connectors (to
provide ground continuity). Ensure that all conduits that are exposed and subject to damage are
constructed of rigid galvanized steel.

Grounding Systems

HP systems are tested and certified only with grounding systems in which a neutral return path
and a protective earth are separate conductors without any inserted impedances. Additionally,
protective earth and return neutral are shorted together at the X0 bonding junction on the
secondary side of the newly derived power source.
IT Power System
HP products have not been evaluated for connection to an IT power system (an AC distribution
system having no direct connection to earth according to IEC 60950).
A product requires two methods of grounding:
• Power distribution safety
• High-frequency intercabinet

Power Distribution Safety Grounding (LAHJ)

The power distribution safety grounding system connects various points in the power distribution
system to earth ground using green (green/yellow) wire ground conductors. To protect computer
room personnel against shock hazards from current leakage and fault conditions, tie the ground
connections to metal chassis parts.
Power distribution systems consist of several parts that should be solidly interconnected to
provide an equipotential ground to all points.

Main Building Electrical Ground

The main electrical service entrance equipment must have an earth ground connection as required
by applicable codes. Such connections as a grounding rod or building steel provide an earth
ground.

Electrical Conduit Ground

All electrical conduits must be made of rigid metallic conduit that is securely connected together
or bonded to panels and electrical boxes so as to provide a continuous grounding system.

Power Panel Ground

Ground each power panel to the electrical service entrance with green (green/yellow) wire ground
conductors. Size the green (green/yellow) wire ground conductors per applicable codes (based
on circuit-over-current device ratings). The PE (Protective Earth) wire gauge may be a larger
diameter wire but not a smaller diameter wire than the AC input power distribution wire.
NOTE: The green wire ground conductor mentioned above can be a black wire with green
tape. (LAHJ)

Computer Safety Ground

Ground all computer equipment with the green (green/yellow) wire included in the branch
circuitry. Connect the green (green/yellow) wire ground conductors to the appropriate power
panel and size them per applicable codes (based on circuit-over-current device ratings).
Electrical Factors 13