Editing Uninterruptible power supply (section)

==Applications==

===''N''&nbsp;+&nbsp;1===
In large business environments where reliability is of great importance, a single huge UPS can also be a single point of failure that can disrupt many other systems. To provide greater reliability, multiple smaller UPS modules and batteries can be integrated together to provide [[Redundancy (engineering)|redundant]] power protection equivalent to one very large UPS. "''N''&nbsp;+&nbsp;1" means that if the load can be supplied by ''N'' modules, the installation will contain ''N''&nbsp;+&nbsp;1 modules. In this way, failure of one module will not impact system operation.<ref>Detailed explanation of optimized ''N''&nbsp;+&nbsp;1 configurations{{cite web|url=http://www.emersonnetworkpower-partner.com/ArticleDocuments/172/Balancing%20Scalability%20and%20Reliability%20in%20the%20Critical%20Power%20System.pdf.aspx|format=PDF|title=Balancing Scalability and Reliability in the Critical Power System: When Does ''N''&nbsp;+&nbsp;1 Become Too Many&nbsp;+&nbsp;1?|url-status=dead|archive-url=https://web.archive.org/web/20160303221250/http://www.emersonnetworkpower-partner.com/ArticleDocuments/172/Balancing%20Scalability%20and%20Reliability%20in%20the%20Critical%20Power%20System.pdf.aspx|archive-date=2016-03-03}}</ref>

===Multiple redundancy===
Many computer servers offer the option of redundant [[Power supply unit (computer)|power supplies]], so that in the event of one power supply failing, one or more other power supplies are able to power the load. This is a critical point – each power supply must be able to power the entire server by itself.

Redundancy is further enhanced by plugging each power supply into a different circuit (i.e. to a different [[circuit breaker]]).

Redundant protection can be extended further yet by connecting each power supply to its own UPS. This provides double protection from both a power supply failure and a UPS failure, so that continued operation is assured. This configuration is also referred to as 1&nbsp;+&nbsp;1 or 2''N'' redundancy. If the budget does not allow for two identical UPS units then it is common practice to plug one power supply into [[mains power]] and the other into the UPS.<ref>Detailed explanation of UPS redundancy options{{cite web|url=http://www.emersonnetworkpower.com/en-US/Brands/Liebert/Documents/White%20Papers/High-Availability%20Power%20Systems,%20Part%20II_Redundancy%20Options.pdf|title=High-Availability Power Systems, Part II: Redundancy Options|access-date=2018-12-11|archive-url=https://web.archive.org/web/20130326072431/http://www.emersonnetworkpower.com/en-US/Brands/Liebert/Documents/White%20Papers/High-Availability%20Power%20Systems,%20Part%20II_Redundancy%20Options.pdf|archive-date=2013-03-26|url-status=dead}}</ref><ref>{{Cite journal|last=Heydari-doostabad|first=Hamed|date=January 2019|title=A new approach to design an observer for load current of UPS based on Fourier series theory in model predictive control system|url=https://www.sciencedirect.com/science/article/pii/S0142061517316083|journal=International Journal of Electrical Power & Energy Systems|volume=104|issue=1|pages=898–909|doi=10.1016/j.ijepes.2018.07.047|bibcode=2019IJEPE.104..898H |s2cid=116458248 |issn=0142-0615|url-access=subscription}}</ref>

===Outdoor use===
When a UPS system is placed outdoors, it should have some specific features that guarantee that it can tolerate weather without any effects on performance. Factors such as temperature, [[humidity]], rain, and snow among others should be considered by the manufacturer when designing an outdoor UPS system. [[Operating temperature]] ranges for outdoor UPS systems could be around −40&nbsp;°C to +55&nbsp;[[Celsius|°C]].<ref>Refer to safety standard IEC 60950-22 or a local derivative according to location e.g. EN 60950-22 (Europe); UL 60950-22 (USA)</ref>

Outdoor UPS systems can either be pole, ground (pedestal), or host mounted. Outdoor environment could mean extreme cold, in which case the outdoor UPS system should include a battery heater mat, or extreme heat, in which case the outdoor UPS system should include a fan system or an air conditioning system.

[[File:Sunny Boy 3000.jpg|thumb|right|300px|Internal view of a solar inverter. Note the many large capacitors (blue cylinders), used to store energy briefly and improve the output waveform.]]
A '''solar inverter''', or '''PV inverter''', or '''solar converter''', converts the variable [[direct current]] (DC) output of a [[photovoltaic]] (PV) [[solar panel]] into a [[utility frequency]] [[alternating current]] (AC) that can be fed into a commercial electrical [[utility grid|grid]] or used by a local, [[off-grid]] electrical network. It is a critical [[Balance of system|BOS]]–component in a [[photovoltaic system]], allowing the use of ordinary AC-powered equipment. Solar inverters have special functions adapted for use with photovoltaic arrays, including [[maximum power point tracking]] and anti-[[islanding]] protection.