|
Alternating Current (AC)
|
An electric current
that reverses its direction at regularly recurring intervals. |
| Audible
noise
|
A measure
of the noise emanating from an uninterruptible power system (UPS) at audible
frequencies. |
| Backup
|
(1) To copy information
usually to a diskette or tape, for safekeeping. (2) Pertaining to a procedure,
technique, or hardware used to recover lost or destroyed data or to keep
a system operating. (3) Pertaining to a system or device, file or facility
that can be used in the event of a malfunction or loss of data. (4) Sometimes
a UPS is referred to as a "backup" power supply. |
| Blackout
|
A zero voltage condition
lasting for more than two cycles. |
| Bridge
|
A functional unit
that interconnects networks or systems with the same or similar architecture. |
| Brownout
|
A steady state of
low voltage, but not zero voltage. |
| Bypass
|
(1) To eliminate
a station or an access unit from a ring network by allowing the data to
flow in a path around it. (2) One of the basic operating sections of a UPS.
(3) One of the four basic modes of UPS operation. |
| Common
mode noise
|
Noise measured between
the electrical line and ground. |
| Common
Mode noise Rejection (CMNR)
|
The ability of a
UPS to block common mode noise from traveling between input and output. |
| Critical
equipment
|
Equipment such as
computers, communications systems or electronic process controls, whose
operation is affected by momentary or continuous power disturbances, including
waveform distortion. |
| Direct
Current (DC)
|
An electric current
in which the flow of electrons is in one direction, such as supplied by
a battery. |
| Double
conversion
|
A UPS design in
which the flow of electrons is in one direction, such as supplied by a battery. |
| Downtime
|
The time during
which a functional unit cannot be used because of a fault within the functional
unit or within the environment. |
| Efficiency
|
For a UPS, output
power divided by input power. Efficiency measures the power required to
run the UPS. |
| Electrical
line noise
|
Radio frequency
interference (RFI), electromagnetic interference (EMI), and other voltage
or frequency disturbances. |
| Electromagnetic
Interference (EMI)
|
Electrical interference
that can cause equipment to work improperly. EMI can be seperated into conducted
EMI (interference conducted through cables out of the UPS) and radiated
EMI (interference conducted through the air). |
| Ethernet
|
A baseband local
area network that allows multiple stations to access the transmission medium
at will without prior coordination, avoids contention by using carrier sense
and degerence and resolves contention by using collision and transmission.
Ethernet uses carrier sense multiple access with collision detection (CSMA/CD). |
| Frequency
variation
|
A change in frequency. |
| Gateway
|
A functional unit
that interconnects two computer networks with different network architectures. |
| Hertz
(Hz)
|
A unit of frequency
equal to one cycle per second. |
| High
voltage spike
|
Rapid voltage peak
up to 6,000 volts. |
| Hot-swappable
|
The ability to change
the battery without taking the critical load off the UPS. |
| Input
voltage range
|
The voltage range
within which a UPS operates in "normal" mode and does not require
battery power. |
| Inverter
|
UPS assembly that
converts internal DC power to output AC power to run user's equipment. When
the inverter is supporting 100% of the load at all times, as with online
UPS, there is no break from utility power to battery power. |
| Kilovolt
Ampere (kVA)
|
An approximation
of available power in an AC system that does not take power factor into
account. |
| Lead
time
|
The amount of time
before a product will be shipped. |
| Line-interactive
|
An offline UPS topology
in which the system interacts with the utility line in order to regulate
the power to the load |
| Load
crest ratio
|
The peak current
required by a load divided by the root mean squared value. (Extreme non-linear
loads may have a crest ratio of 3:1). |
| Load
regulation
|
Controlling the
flow of power to the UPS. |
| Local
Area Network (LAN)
|
(1) A computer network
located on a user's premises within a limited geographical area. (2) A network
in which a set of devices are connected to one another for communication
and that can be connected to a larger network. (3) LANs are usually connected
by means of a continuous cable or in-house, voice-data telephone system. |
| Maintenance
bypass
|
An external wiring
path to which the load can be transferred in order to upgrade or perform
service on the UPS without powering down the load. |
| Make-before-break
|
Operating sequence
of a switch or relay, where a new connection is made before the existing
one is broken. |
| Noise
|
(1) A disturbance
that affects a signal and that can distort the information carried by the
signal. (2) Random variations of one or more characteristics of any entity
such as voltage, current or data. (3) Loosely, any disturbance tending to
interfere with normal operation of a device or system. |
| Offline
|
(1) Any UPS that
does not fit the definition of online (see below). Line-Interactive and
standby topologies are offline. (2) Pertaining to the operation of a functional
unit that takes place either independently of, or in parallel with, the
main operations of a computer. (3) Neither controlled by, or communicating
with a computer. |
| One
line diagrams
|
A schematic or a
multiphase electrical system where one line is used to represent all phases. |
| Online
|
(1) A UPS that provides
power to the load from its inverter 100% of the time, regulating BOTH voltage
and frequency, usually double conversion topology. (2) Pertaining to the
operation of a functional unit when under the control of the computer. (3)
Pertaining to a user's ability to interact with a computer. (4) Controlled
by or communicating with a computer. |
| On-Site
|
At the site where
the UPS is located. |
| Operating
temperature
|
The temperature
range through which a UPS can sustain normal operations (typically 0 - 40
C). |
| Plug-In
|
Hardware attachment
used to expand the capabilities of a system. |
| Plug
and play
|
An electrical device
that does not require extensive setup to operate. |
| Point-Of-Sale
(POS) device
|
A device used in
retail establishments to record sales information in a form that can be
input directly into a computer. This intelligent terminal is used to capture
data in reatil sotres, often with the capactiy of verifying the credit worthiness
of the customer. |
| Power
factor
|
The ratio of real
power to apparent power. Watts divided by VA. |
| Power
Sag
|
Low voltage (below
nominal volts). |
| Power
Surge
|
High voltage (above
nominal volts). |
| Powertrain
|
Main power carrying
portion of an electrical system. |
| Premium
|
5 year parts and
labor |
| Private
Branch Exchange
|
(1) An automatic
or manual private telephone exchange for transmission of calls to and from
the public telephone network. (2) A switching system loctaed on a customer's
premises that consolidates the number of inside lines into a smaller number
of outside lines. |
| Rackmount
|
Ability to mount
an electrical assembly into a standardized rack. |
| Rectifier
|
UPS component that
converts invoming AC power to DC power for feeding the inverter and for
changing the battery. |
| Relay
communication
|
Communication between
a UPS and a computer through the opening and closing of solid state relays
which are pre-defined to indicated UPS status. |
| Router
|
(1) A computer that
determines the path of a network traffic flow. (2) An attaching device that
connects two LAN segments, which use different architectures. |
| RS-232
|
The standard for
serial interfaces (serial refers to the eight bits of each character successively
sent down one wire) used by most computers, modems and printers. |
| Run
Time
|
(1) Refers to the
amount of time the battery in a UPS is designed to support the load. (2)
An instant at which the execution of a particular computer program takes
place. (3) The amount of time needed for the execution of a particular computer
program. |
| Shut
down (verb)
|
The process of ending
operation of a system or subsystem. |
| Shutdown
(noun)
|
The termination
of electrical power to all or part of the computer system components, whether
intentional or inadvertent. |
| Sine
wave
|
A waveform that
represents periodic oscillations of a pure frequency. |
| Simple
Network Management Protocol (SNMP)
|
Request/response
type of protocol that gathers management information |
| Single
phase
|
Power system with
only one primary waveform. |
| Stand-alone
|
Operation that is
independent of any other device, program or system. |
| Standard
|
2 years parts and
labor, return to factory. |
| Standby
|
(1) UPS technology
where power is applied to the load directly from the utility under normal
operation, but switched to the inverter and battery for emergency support
(offline topology). (2) A condition of equipment that permits complete resumption
of stable operations within a short span of time. (3) A druplicate set of
equipment to be used if a primary unit becomes unusable because of malfunction. |
| Telecommunication
|
(1) The transmission
of control signals and information between two or more locations, such as
telegraph, radio, or television. (2) The transmission of data between computer
systems over telecommunications lines and between a computer system and
a remote device. |
| Three-phase
|
A power system with
three primary voltage waveforms spaced equally (in time) out of phase with
each other. |
| Token
ring
|
A network with a
ring topology that passes tokens from one attaching device to another. |
| Total
Harmonic Distortion (THD)
|
Describes how much
the circuit voltage deviates from a perfect sine wave. A poor voltage THD
is most often manifested in a flat topped waveform that comes from the inability
of a power source to respond the demands of highly non-linear loads. |
| Transverse
Mode Noise Rejection (TMNR) |
The ability of a
UPS to block transverse-mode noise from traveling between input and output. |
| Turnkey
system
|
A system that is
ready to use when installed and supplied to the user in ready-to-run condition
possible customized to a specific user or application. Delivery does not
necessarily include preparatory work on the user's data. |
| Uninterruptible
|
Without pause, constant. |
| Uninterruptible
Power System (UPS)
|
An electrical system
designed to provide instant, transient-free backup power during power failure
or fault. Some UPSs also filter and/or regulate utility power (line conditioning). |
| UPS
bypass
|
A second source
of power to which the UPS can transfer the load in the event of an overload
or electronics failure within the UPS. |
| Uptime
|
Dedicated term for
available time. Operable time. Operating time. |
| Volt
(V) Voltage
|
Electrical pressure that pushes
current through a circuit. High voltage in a computer circuit is represented
by (1) Low (or zero) voltage is represented by a 0.
|
| VoltAmps
(VA)
|
Voltage X Amps |
| Volts
Direct Current
|
(VDC) |
| Volts
Alternating Current
|
(VAC) |
| Wide
Area Network (WAN)
|
(1) A Network that
provides communication services to a geographic area larger than that served
by a local area network or a metropolitan area network, and may use or provide
public communication features. (2) A data communications network designed
to serve an area of hundreds or thousands of miles. (3) WANs are generally
implemented by linking together several remote local are networks through
the use of gateways and bridges over dedicated phone lines. |
