Power cable usage guidelines
Hitachi storage systems are intended for rack installation and ship with power cords.
Installation and service requirements may require additional cords and cables to be
ordered. The type of power cable required by a given installation is determined primarily
by the:
■
Type of AC line feed provided by the facility.
■
Type of AC source (wall outlet or modular and monitored PDU) to be used.
■
Serviceability of components to be connected.
Storage systems require a country-specific power cable for direct connection to a facility
AC feed.
Storage systems are designed to allow replacement of hot-pluggable components
without removing the chassis from the rack. As a result, power cables can be short
because cable movement is of minimal consideration.
Three-phase power considerations for racks
Increasing power requirements for racks are making the use of three-phase power at the
rack level compelling.
■
With single-phase power, at any given time the voltage across the hot and neutral
conductors can be anywhere between its peak (maximum) and zero. Electrical
conductors must be large to meet high amperage requirements.
■
Three-phase power uses three cycles that are 120 degrees out of phase, which never
allows the voltage to drop to zero. The more consistent voltage derived from the
three hot conductors results in smoother current flow and allows small-gauge
conductors to be used to distribute the same amount of AC power. As a result, the
load balancing and increased power handling capabilities of three-phase distribution
can result in more efficient and less costly installations that require fewer AC cables
and PDUs.
Cable management
Rack installations should be planned for operational efficiency, ease of maintenance, and
safety. Hitachi offers the Backend Configuration Utility (BECK), a graphical, cable-
management application that can relieve the typical cable congestion created when
populating a rack with storage systems and their accessories.
Power cable usage guidelines
Appendix D: Data and power cables
Hitachi Virtual Storage Platform G700 Hardware Reference Guide
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