HP StorageWorks XP24000 Disk Array Site Preparation Guide, v01 (AE131-96002, June 2007)

If necessary, an HP representative can measure your power line noise level and make appropriate
recommendations concerning the use of line treatment devices.
UPS
Most disk array units are installed in data centers where an uninterruptible power supply (UPS) strategy
is already in place. However, if you are making your first large disk array purchase, you may need
a separate UPS solution.
CAUTION:
This section discusses a product UPS. If you are planning or already have a site-wide UPS, HP recommends
against using a product UPS powered by a site-wide UPS for the HP XP24000.
Design your UPS to account for worst-case voltage (rated voltage minus 10 percent) and a maximum
configuration of DKC/DKUs. Also include a phase imbalance of 15 percent in the calculation. For
system power specifications, see Electrical specifications for the HP XP24000 Disk Array
Sources of electrical interference
Ensure that the disk array is protected from sources of electrical interference as explained in the
following table.
Table 22 Sources of electrical interference
DescriptionPotential source
Convenience power outlets for building maintenance equipment (such
as vacuum cleaners and floor buffers) must be wired from circuit breakers
on a power panel separate from the computer system panel. The ground
wires from these outlets must be connected to the normal building
distribution panel and not to the system ground.If a separate power
source and separate ground are not provided, operation of janitorial
equipment can induce electrical noise and cause abnormal operation of
the computer system. Your electrician can verify whether or not
maintenance outlets are on separate panels.
Wall outlets
In geographical areas subject to lightning storms, it may by advisable
to install lightning protection for both personnel and computer systems.
The principles of lightning protection and personnel safety are outlined
in detail in the lightning protection code contained in the National Fire
Protection Association (NFPA) Handbook.
Lightning
The HP system is specifically designed to reduce its susceptibility to
radiated and conducted interference. Electromagnetic interference can
cause a variety of system problems. An HP representative can advise
you about the most common causes of electromagnetic interference.
Electromagnetic interference
XP24000 Disk Array Site Preparation Guide 45