HP 3000/9x9KS Series, Site Preparation And Requirements Manual

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2-9
Receptacles
When receptacles are used to connect system components to AC power, the receptacles must include a
dedicated ground connection that is insulated from the receptacle box. It is important that the
receptacle box be grounded with an additional ground connection that is non-dedicated.
(The additional ground can be a hard metal conduit.)
When installing receptacles, ensure that each receptacle has its own neutral (if required) and ground.
Using the same neutral or ground for more than one circuit will cause voltage loss, heat problems, and
can result in a fire hazard. A shared neutral conductor that fails open-circuit will result in possible
over-voltage damage to equipment.
Computer equipment power cord and plug requirements also vary from country to country. Unusual
power cords and plugs that cannot be ordered must be fabricated by a qualified electrician to meet
local safety codes and requirements.
Power Line Transients and Noise
Heavy electrical loads from nearby machinery or equipment (i.e., elevators or electric welders) can
cause power transients and noise which may cause system errors. This can occur even if the other
equipment is on a separate circuit breaker. Under these conditions, you should provide a separate
(completely independent) power panel. This should have an isolated ground and separate circuit
breaker and be fed directly from the main building power source or a secondary power source.
See the Computer Products Site Preparation Resource Guide, Section 3, for additional information.
Your Hewlett-Packard CE can monitor your power line for electrical noise and transients. If found,
they can make appropriate recommendations concerning the use of line conditioning devices.