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Questions tagged [ups]

uninterruptible power supply

An uninterruptible power supply, also uninterruptible power source, UPS or battery/flywheel backup, is an electrical apparatus that provides emergency power to a load when the input power source, typically mains power, fails. A UPS differs from an auxiliary or emergency power system or standby generator in that it will provide instantaneous or near-instantaneous protection from input power interruptions by means of one or more attached batteries and associated electronic circuitry for low power users, and or by means of diesel generators and flywheels for high power users. The on-battery runtime of most uninterruptible power sources is relatively short—5–15 minutes being typical for smaller units—but sufficient to allow time to bring an auxiliary power source on line, or to properly shut down the protected equipment.

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Source: wikipedia

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Can I plug a 15A UPS into a 30A receptacle?

I know that typically electronics draw only as much current as they need. Is this the case with UPSs? I have a 120 volt, 30 amp circuit, and am replacing the UPS plugged into that circuit with a lower wattage UPS. This UPS has a 15 amp plug. Is it…
bsamek
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Why do I need a raid battery pack?

I'm trying to understand why one would add a batterypack to a raid card. It seems to me like if power goes down, running just the raid card is going to do little good: without power for HDs and motherboard, writing in-memory data isn't going to work…
user60704
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Sysadmin in the Developing World: What are the differences between various kinds of power protection?

Hello I'm an ICT (InfoComTech) US Peace Corps volunteer deep in Tanzania who has the task of managing and advising concerning our college's two SunFire Sun Ray Servers and Dell Proxy server (on 2 Tripplite 2000VA rackmount Server UPSs and behind 30A…
thadk
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datacenter UPS electronics/chassis expected lifetime

We have a small datacenter with seven APC 5000VA rackmount UPS. These have had regular battery replacement, but have just passed 10 years of service. We also have a boxed spare unit of the same model in storage. The devices have seen very few…
rmalayter
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How to configure UPS to restart servers in the right sequence?

Here we have some servers and almost each of them has a dedicated UPS. There are dependencies between them so they must be switched on in the correct sequence. Ultimately we are experiencing serious problems with the power supply, so the servers are…
Filippo
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New UPS Batteries Dying in Months

This is something that has had me stumped for over a year. I have 3 APC SmartUPS 3000's and a few non APC units in my server room. Each unit has it's own dedicated connection to the breaker panel. It seems that I am having to replace the batteries…
TriadicTech
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Daisy Chaining UPS Power Cable

I have a rackmount UPS. The UPS has a 6ft long 12AWG thick power cable that powers it from one of the server room's 20A wall plugs. The current orientation of the cabinets is not ideal. All but this one are easily moved, however this cabinet's UPS'…
SnakeDoc
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How can I calculate if a UPS is sufficient for my requirements?

I am not that of an electricity knowledgable person, so I'll try to put as much info as possible. I have a Rack Mount UPS of 1800 Watts Model: PRP 3050 RM (in total I have 2 of these - talking about one specifically) I had to change it's batteries…
Saariko
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Does UPS Rack Position Matter

Short version of question: Is there any reason a UPS (or any other device) should be at a particular level in a rack. Long version (with explanation): I have a full height rack with two servers, two Dell rail mount UPS units, a direct attached…
user426724
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What purpose does the battery serve on a battery-backed caching RAID controller if the server is on an uninterruptible power supply?

Is the battery redundant if the server is on a properly-sized UPS? There is an option to force write-back mode and I want to understand the risk. It is my understanding that it helps against power failures while data in the cache has not been…
RPC
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One server, Two APC UPS on redundant power supplies : How to trigger shutdown?

I have a server racked and its redundant power supplies plugged in two APC Smart-UPS 3000 XLM. Each UPS is connected to two different mains power sources. Two instances of apcupsd are running, each one connected to its own UPS. They can both detect…
Falken
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UPS Requirements - Max load or actual load?

One of our UPS units failed this weekend (Happy new year!), and so I'm on the look out to replace it. I've done the calculations for our power requirements, and it comes out just under 8000W. This is based on data sheets from manufacturers of the…
adamstrawson
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Automatic power on after graceful shutdown on UPS

This is my basic setup: I run a server (DL380 G7; linux 3.13 kernel) that is host to ~10 virtual machines It is set for automatic power on I use NUT for UPS management Graceful shutdown duration of the Host (including first shutting down the VMS)…
martin
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What less obvious ways are there to misuse and damage a UPS?

I've never had an uninterruptible power supply and think of buying one. What not-so-obvious things should I not do to the UPS so that it lives longer? I don't mean some obvious abuse like dropping/exposing to direct heat/exposing to wrong voltage. I…
sharptooth
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UPS - Two computers - How to get them to both shutdown when battery is low?

Short Version: How do I get 2 computers to shutdown when a UPS battery gets low? Long Version: I have an APC UPS, the RS 1500. It has a USB cord that goes into my main dev computer. My dev computer will shutdown when the battery gets low. However,…
Brian Webster
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