Receptacles; Fault-Tolerant Ac Power Example - HP StorageWorks XP12000 - Disk Array Site Preparation Manual

• An insulated grounding conductor that is identical in size and 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.
• The grounding conductor should be grounded to earth at the service equipment or other acceptable
building earth ground such as the building frames (in case of a high-rise steel-frame structure).
• IT-configured grounding systems are not certified for use with the HP system 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 HP system requires a solidly
conductor-connected ground and may require a separate neutral in the case of WYE or STAR
connections. For the HP system, TN grounding systems are preferred.

Receptacles

Each disk array rack has two or four separate connections to AC power.
• For racks with two AC power connections, each input must be capable of supporting the rack's
entire current demand.
• For racks with four AC power connections, the two inputs to AC Box 1 or the two inputs to AC
Box 2 must be capable of supporting the rack's entire current demand.
Figure 9 illustrates faul-tolerant wiring.
Figure 9 Fault-tolerant AC power example
When receptacles are used to connect disk array components 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.
Specific power plugs and receptacles are required for the DKC and DKUs depending on the power
option you specify when ordering the disk array. The power cords on 60 Hz cabinets are shipped
with plugs attached and connected. The power cords on 50 Hz cabinets are shipped without plugs.
44 Site requirements for the HP XP12000 Disk Array