HP Integrity rx8620 Site Preparation Manual page 54

General Site Preparation Guidelines
Delivery Survey
L-N
Latent cooling capacity The capability of an air-conditioning system to remove heat from the air.
Leakage current A term relating to current flowing between the AC supply wires and earth ground. The
term does not necessarily denote a fault condition. In power supplies, leakage current usually refers to the
60-Hz current, which flows through the EMI filter capacitors that are connected between the AC lines and
ground.
Maximum input current The operating current of the product equal to the maximum load divided by the
minimum input voltage.
NEBS All electronic equipment has the potential to interfere with other electronic equipment. Interference
can be caused by electromagnetic radiation, the grounding system, the electrical power connection, excessive
heat or blocking the natural airflow, and connecting wires or cables. The Federal Communications
Commission (FCC) regulates a portion of this problem through Part 15 of their rules and regulations. Even
more stringent than the FCC Part 15 requirements, Network Equipment Building Standards (NEBS) covers
a large range of requirements including criteria for personnel safety, protection of property, and operational
continuity. The documents cover both physical requirements including: space planning, temperature,
humidity, fire, earthquake, vibration, transportation, acoustical, air quality and illumination; and electrical
criteria including: electrostatic discharge (ESD), electromagnetic interference (EMI), lightning and AC power
fault, steady state power induction, corrosion, DC potential difference, electrical safety and bonding and
grounding.
O-R
PCA Printed Circuit Assembly; also referred to as a printed circuit board (PCB).
PCI Currently, the most popular local I/O bus, the Peripheral Component Interconnect (PCI) bus was
developed by Intel and introduced in 1993.
PICMG A consortium of companies involved in utilizing PCI for embedded applications. The PCI Industrial
Computer Manufacturers Group (PICMG) controls the PICMG specification.
Power factor The ratio of true power to apparent power in an AC circuit. In power conversion technology,
power factor is used in conjunction with describing the AC input current to the power supply.
RMS Root-mean-square. Term that refers to the most common mathematical method of defining the effective
voltage or current of an AC wave. To determine RMS value, three mathematical operations are carried out on
the function representing the AC waveform: (1) The square of the waveform function (usually a sine wave) is
determined. (2) The function resulting from step 1 is averaged over time. (3) The square root of the function
resulting from step 2 is found.
S-T
Theoretical maximum power consumption Maximum wattage of a given configuration, assuming
worst-case conditions (thermal tolerances, workloads, and so forth) on all system components. It is extremely
unlikely that any customer will experience this level of power consumption.
Tonnage The unit of measure used in air-conditioning to describe the heating or cooling capacity of a system.
One ton of heat represents the amount of heat needed to melt one ton (2000 lb) of ice in one hour and 12,000
Btu/h equals one ton of heat.
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Chapter 2