Uninterruptible Power Supply

(redirected from UPS unit)

Uninterruptible Power Supply

(hardware)
(UPS) A battery powered power supply unit that is guaranteed to provide power to a computer in the event of interruptions in the incoming mains electrical power. Different rating UPSs will provide power for different lengths of time.

Modern UPSs connect to the computer's serial port and provide information such as battery time remaining, allowing the computer to shut down gracefully before complete loss of power.

UPS

(Uninterruptible Power Supply) A device that provides battery backup when the electrical power fails or drops to an unacceptable voltage level. Small UPS systems provide power for a few minutes; enough to power down the computer in an orderly manner, while larger systems have enough battery for several hours. In mission critical datacenters, UPS systems are used for just a few minutes until electrical generators take over.

UPS systems can be set up to alert file servers to shut down in an orderly manner when an outage has occurred, and the batteries are running out.

Surge Suppression and Voltage Regulation
A surge protector filters out surges and spikes, and a voltage regulator maintains uniform voltage during a brownout, but a UPS keeps a computer running when there is no electrical power. UPS systems typically provide surge suppression and may provide voltage regulation. See surge suppression.

Standby and Line Interactive
A standby UPS, also called an "offline UPS," is the most common type of UPS found in a computer or office supply store. It draws current from the AC outlet and switches to battery within a few milliseconds after detecting a power failure.

The line interactive UPS "interacts" with the AC power line to smooth out the waveforms and correct the rise and fall of the voltage.

Online UPS
The online UPS is the most advanced and most costly UPS. The inverter is continuously providing clean power from the battery, and the computer equipment is never receiving power directly from the AC outlet. However, online units contain cooling fans, which do make noise and may require some location planning for the home user or small office.


Three UPS Types
All UPS systems switch to battery when the power fails. The difference is how they handle the power under normal circumstances. Standby units provide limited attenuation whereas line interactive systems will adjust the voltage and smooth out bad harmonics. Online systems are constantly regenerating clean power. (Diagrams courtesy of MGE UPS SYSTEMS.)


Three UPS Types
All UPS systems switch to battery when the power fails. The difference is how they handle the power under normal circumstances. Standby units provide limited attenuation whereas line interactive systems will adjust the voltage and smooth out bad harmonics. Online systems are constantly regenerating clean power. (Diagrams courtesy of MGE UPS SYSTEMS.)







Size Does Matter
When the power goes off, the unit on the right will keep more equipment running for a longer time than the one on the left, because the battery is larger. Battery size is an important criterion when selecting UPS systems.








Backing Up the Backup
In APC's Symmetra Power Array, all modules share in the total load; thus, any unit can fail and be replaced without jeopardizing the security the UPS was intended to provide in the first place. (Image courtesy of American Power Conversion Corporation.)
References in periodicals archive ?
Haq Nawaz of Naro Kaley area said a UPS unit worked for two or three hours without stopping but it didn't charge if electric supply was suspended for long hours.
Last month, workers at the UPS unit rejected a tentative contract and their contract extension expires on November 12, after which the 11,000 members of the Teamsters union could go on strike.
M2 EQUITYBITES-April 3, 2013-Delta Air Lines ups unit revenues in March(C)2013 M2 COMMUNICATIONS http://www.m2.com
UPS System Power Loss Formula and Spreadsheet Verification UPS Data--Manufacturer Literature UPS Configuration Number Manufacturer Rated UPS Unit UPS System No.
The UPS unit's plug-and-power connections and hot-swappable batteries and electronics modules simplified the installation.
How to choose the right surge suppressor and UPS unit? APC provides the following tips to help you in making the right decision:
With a UPS unit, Hannaford stores can opt to do a "controlled shutdown" during a power blackout--checking out shoppers who are in the store and then closing the store until power is restored, says Al Carville, vice, president of information systems and technology.
It is now possible to place a static UPS unit in the same room as the computer equipment representing the critical load.
Each On-Line UPS unit features true on-line double-conversion technology and supports wide input voltage ranges.
Supply of one 6 KVA capacity UPS unit & six 5 KVA capacity UPS units.
Once you have determined which UPS unit is most suitable for your company, the next step involves examining the pertinent features for your chosen UPS type.