Grounding Requirements - HP StorageWorks XP128 Installation Manual

Grounding requirements

Receptacles
Preparing for installation
Your disk array must meet all of the following conditions:
• An insulated grounding conductor that is identical in size, insulation
material, and thickness to the ungrounded branch-circuit supply
conductors. It should be green, with or without yellow stripes, and is to
be installed as a part of the branch circuit that supplies the unit or
system. This means the ground conductor must be run in the same
conduit, armored cable, or other cable bundle as the phase wires.
• Grounding as prescribed by your local country codes.
• The grounding conductor mentioned above should be grounded to
earth at the service equipment or other acceptable building earth
ground such as the building frames (in the case of a high rise steel
frame structure).
• IT configured grounding systems are not certified for use with the
XP128 as these grounding systems may not have solidly
conductor-connected grounded power systems and/or they may have
resistive impedance inserted in ground and/or neutral lines. The
XP128 requires a solidly conductor-connected ground and may require
a separate neutral in the case of WYE or STAR connections.
When receptacles are used to connect your disk array to AC power, they
must include a dedicated ground connection that is insulated from the
receptacle. It is important that the receptacle box be grounded with an
additional ground connection that is separate from the dedicated ground.
The additional ground can be hard conduit.
Each disk array cabinet has two or four separate connections to AC power.
For disk array cabinets with two connections to AC power, each input must
be capable of supporting the entire current demand for the cabinet. For disk
array cabinets with four connections to AC power, the two inputs to AC
Box 1 or the two inputs to AC Box 2 must be capable of supporting the
entire current demand for the cabinet. The figure below shows two
examples of the fault-tolerant operation of the disk array.
37