Uninterruptible power supply
electrical device that uses batteries to prevent a power flow interruption
An uninterruptible power supply (UPS) or uninterruptible power source is an electrical apparatus that provides emergency power to a load when the input power source or mains power fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide near-instantaneous protection from input power interruptions, by supplying energy stored in batteries, supercapacitors, or flywheels.
The on-battery run-time of most uninterruptible power sources is relatively short (typically ranging from 5 to 15 minutes) but sufficient to start a standby power source or properly shut down the protected equipment. It is a type of continual power system. A UPS is typically used to protect hardware such as computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption or data loss. UPS units range in size from units designed to protect a single computer without a video monitor (around 200 volt-ampere rating) to large units powering entire data centers or buildings.
Common power problems
The primary role of any UPS is to provide short-term power when the input power source fails. However, most UPS units are also capable in varying degrees of correcting common utility power problems:
Voltage spike or sustained overvoltage
Momentary or sustained reduction in input voltage
Voltage sag
Noise, defined as a high frequency transient or oscillation, usually injected into the line by nearby equipment
Instability of the mains frequency
Harmonic distortion, defined as a departure from the ideal sinusoidal waveform expected on the line
Some manufacturers of UPS units categorize their products in accordance with the number of power-related problems they address.
A UPS unit may also introduce problems with electric power quality. To prevent this, a UPS should be selected not only by capacity but also by the quality of power that is required by the equipment that is being supplied.
“Uninterruptible power supply” enters the record as electrical device that uses batteries to prevent a power flow interruption. Crown Archives preserves that source wording while asking what Uninterruptible, power and supply can confirm, complicate or overturn.
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