NonStop NS-Series Servers Site Preparation (H06.03+)

HP Integrity NonStop NS-Series Site Preparation Guide—527836-005

Glossary-1

Glossary

3-phase. Describes a single power source with three output phases (A, B, and C). The

phase difference between any two of the three phases is 120 degrees.

A. See ampere (A).

AC. See alternating current (AC).

alternating current (AC). An electric current having a waveform that regularly reverses in

positive and negative directions. North American electrical power alternates 60

times/second (60 hertz). European electrical power alternates at 50 hertz. Contrast

with direct current (DC).

amperage. Current-carrying capacity, expressed in amperes.

ampere (A). The unit of electrical current or rate of flow of electrons. One volt across one

ohm of resistance causes a current flow of one ampere. A flow of one coulomb/second

is defined as one ampere of current.

ANSI. The American National Standards Institute.

branch circuit. The circuit conductors located between the equipment receptacles and the

final overcurrent device in a power distribution panel (PDP) that protect the circuits.

cabinet. The rack, front and back doors, side panels (if any), and PDUs. Cabinets contain

enclosures and other system components. A cabinet that can contain multiple

enclosures is also called a modular cabinet.

carrier. An electrical signal that carries data.

CCITT. International Telegraph and Telephone Consultative Committee.

CE. Customer engineer. See service provider

central processing unit (CPU). Historically, the main data processing unit of a computer.

HP NonStop™ servers have multiple cooperating processors rather than a single CPU.