822 lines
40 KiB
Plaintext
822 lines
40 KiB
Plaintext
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UPS HOWTO
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Eric Steven Raymond
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[http://www.catb.org/~esr/] Thyrsus Enterprises
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Nick Christenson
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Revision History
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Revision 2.2 2007-05-22 Revised by: esr
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Minor update with more info about battery types.
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Revision 2.1 2005-09-28 Revised by: esr
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Link fixes.
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Revision 2.0 2005-08-15 Revised by: esr
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Merged in material by Nick Christenson.
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Revision 1.3 2005-08-17 Revised by: esr
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Fix a bad link.
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Revision 1.2 2004-10-28 Revised by: esr
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Remove a bad link.
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Revision 1.1 2004-02-21 Revised by: esr
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Add a little deployment advice, and stuff on other technologies.
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Revision 1.0 2003-10-07 Revised by: esr
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Initial release.
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An Uninterruptible Power Supply (UPS) is an important thing to have if you
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live in an area where power outages are at all common, especially if you run
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a mail/DNS/Web server that must be up 24/7. This HOWTO will teach you things
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you need to know to select a UPS intelligently and make it work with your
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open-source operating system.
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-----------------------------------------------------------------------------
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Table of Contents
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1. Introduction
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1.1. Why this document?
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1.2. New versions of this document
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1.3. License and Copyright
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2. An Overview of Power Protection
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2.1. Surge suppressors
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2.2. Line Conditioners
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2.3. Uninterruptible Power Supplies
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3. UPS Basics
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3.1. How To Select A UPS
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3.2. Deploying your UPS and other devices: the total picture
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3.3. Software Assistance
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3.4. Preparing Your System For Auto-Reboot
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4. Testing Your UPS
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5. Maintaining Your UPS
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5.1. Service contracts
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5.2. Extending battery life
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5.3. Recalibrating Your UPS
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5.4. Replacing Your Batteries
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5.5. Buying Batteries
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6. Vendor information
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7. Bibliography
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8. Acknowledgements and Related Resources
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1. Introduction
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1.1. Why this document?
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An Uninterruptible Power Supply (UPS) is an important thing to have if you
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live in an area where power outages are at all common, especially if you run
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a mail/DNS/Web server that must be up 24/7. The aging power grid in the U.S.
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has made this a more urgent issue than it used to be even for American
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hackers, but everyone is vulnerable to outages caused by storms and other
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natural phenomena. This document covers both the software and hardware
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aspects of protecting yourself.
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The advice in this document is aimed primarily at small installations ?? one
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computer and one UPS. Thus we'll focus on consumer-grade UPSes, especially
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those designed for home and small-business use. If you are a data center
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administrator running a big server farm, there is a whole different (and much
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more expensive) range of technologies we'll do no more than hint at here.
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The people who contribute to this document can speak only about equipment
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they have experience with. This may reflect a bias toward or against certain
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brands, features, functions, etc. Please keep in mind that the suggestions,
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brand names and functions here are by no means exhaustive, or even
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necessarily applicable to your situation. Also, if you have information that
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is not in this document, please submit it to the maintainer listed above. If
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you submit information, please say whether you'd like it to be attributed to
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you or not. We are more than glad to give credit to the fine people who
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helped with this document, but we want to respect the anonymity of those
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people who would prefer it.
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-----------------------------------------------------------------------------
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1.2. New versions of this document
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You can also view the latest version of this HOWTO on the World Wide Web via
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the URL [http://www.tldp.org/HOWTO/UPS-HOWTO.html] http://www.tldp.org/HOWTO
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/UPS-HOWTO.html.
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-----------------------------------------------------------------------------
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1.3. License and Copyright
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Copyright (c) 2003,2006 Eric S. Raymond.
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Permission is granted to copy, distribute and/or modify this document under
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the terms of the GNU Free Documentation License, Version 1.2 or any later
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version published by the Free Software Foundation; with no Invariant
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Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the
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license is located at [http://www.gnu.org/copyleft/fdl.html] www.gnu.org/
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copyleft/fdl.html.
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Feel free to mail any questions or comments about this HOWTO to Eric S.
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Raymond, <esr@snark.thyrsus.com>. But please don't ask me to troubleshoot
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your general UPS problems; if you do, I'll just ignore you.
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-----------------------------------------------------------------------------
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2. An Overview of Power Protection
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Power protection guards your equipment against blackouts, brownouts, surges,
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and spikes. All these events are anomalies in the flow of mains power that
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can damage your electronic equipment.
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A blackout is a complete interruption of power; some literature considers a
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voltage drop below about 80V to be a blackout as well since most equipment
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will not operate below that level.
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A dropout is a very short (less than one second) blackout.
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A brownout or sag is a decrease in voltage levels which can last for periods
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ranging from fractions of a second to hours. This can be caused by heavy
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equipment coming on line such as shop tools, elevators, compressors etc. Also
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occurs when utility companies deliberately do this to cope with peak load
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times.
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A spike is a tremendous increase in voltage over a very short period of time
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often caused by a direct lightning strike on a power line or when power
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returns after a blackout.
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A surge is a substantial increase in voltage lasting a small fraction of a
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second, often caused when high powered appliances such as air conditioners
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are switched off.
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There are three levels of power protection available to the home computer
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user. The levels are:
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1. Surge Suppressor
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2. Line Conditioners
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3. Uninterruptible Power Supplies
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While this HOWTO mainly focuses on UPSs, we'll start with some basics about
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the other two kinds of power filtering to help you understand where UPSes fit
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in. This is useful even though plummeting UPS prices have made the low-end
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alternatives less interesting than they used to be.
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-----------------------------------------------------------------------------
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2.1. Surge suppressors
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These are basically a fancy fuse between the source and your hardware; they
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clamp down spikes, but can't fill in a low voltage level or dropout.
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This is a bare minimum level of protection that any piece of expensive
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electronics should have. Note that this applies to more than just AC power;
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surge suppressors are available for (and should be used on) phone lines, and
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RS-232 and parallel connections (for use on long lines; generally not needed
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if the devices are colocated with the computer and all devices are protected
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from outside sources). Note also that all devices connected to your computer
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need to be protected; if you put a surge suppressor on your computer but not
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your printer, then a zap on the printer may take out the computer, too.
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An important fact about surge suppressors is that they need to be replaced if
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they absorb a large surge. Besides fuses, most suppressors rely on on
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components called Metal-Oxide Varistors (or MOVs) for spike suppression,
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which degrade when they take a voltage hit. The problem with cheap
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suppressors is that they don't tell you when the MOV is cooked, so you can
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end up with no spike protection and a false sense of security. Better ones
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have an indicator.
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You can buy surge suppressors at any Radio Shack; for better prices, go
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mail-order through Computer Shopper or some similar magazine. All of these
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are low-cost devices ($10-50).
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-----------------------------------------------------------------------------
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2.2. Line Conditioners
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These devices filter noise out of AC lines. Noise can degrade your power
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supply and cause it to fail prematurely. They also protect against short
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voltage dropouts and include surge suppression.
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The Tripp-Lite 1200 I used to have was typical of the better class of line
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conditioners; a box with a good big soft-iron transformer and a couple of
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moby capacitors in it and no conductive path between the in and out sides.
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With one of these, you can laugh at brownouts and electrical storms. A fringe
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benefit is that if you accidentally pull your plug out of the wall you may
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find you actually have time to re-connect it before the machine notices (I
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did this once). But a true UPS is better.
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Netter Trey McLendon has good things to say about Zero Surge conditioners. He
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says: "Our systems at work [...] have been protected for 2.5 years now
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through many a violent storm...one strike knocked [out] the MOV-type
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suppressors on a Mac dealer's training setup across the street from us. The
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Zero Surge just sort of buzzed when the surge came in, with no interruption
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whatsoever. The basic principle is this: ZS units slow down the surge with a
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network of passive elements and then sends it back out the neutral line,
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which is tied to ground outside at the box by code. MOV units shunt the surge
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to ground at the computer, where it leaps across serial ports, network
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connections, etc. doing its deadly work."
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Price vary widely, from $40-400, depending on the power rating and
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capabilities of the device. Mail-order from a reputable supply house is your
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best bet. Line conditioners typically don't need to be replaced after a
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surge; check to see if yours includes MOVs.
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-----------------------------------------------------------------------------
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2.3. Uninterruptible Power Supplies
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The remainder of this document will focus on UPSes. A UPS does three things
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for you. First, it filters the power your machine sees, smoothing out spikes
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and voltage fluctuations that can stress or even damage your electronics.
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Secondly, it provides a certain amount of dwell time in the event your power
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goes out entirely ?? this can often get you through brownouts and short
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blackouts. Third, when the UPS is about to run out of power it can arrange a
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graceful shutdown of your computer so that no unpleasant things happen to
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your disk filesystems. While the risks of unexpected shutdown are much
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lessened in these days of journalling filesystems like Linux's EXT3 or JFS
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from what they once were, ensuring a clean shutdown is still a valuable
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contribution to any system administrator's peace of mind.
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Here's what a UPS will do for you:
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1. Absorb relatively small power surges.
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2. Smooth out noisy power sources.
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3. Continue to provide power to equipment during line sags.
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4. Provide power for some time after a blackout has occurred.
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In addition, some UPS or UPS/software combinations provide the following
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functions:
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1. Automatic shutdown of equipment during long power outages.
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2. Monitoring and logging of the status of the power supply.
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3. Display the Voltage/Current draw of the equipment.
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4. Restart equipment after a long power outage.
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5. Display the voltage currently on the line.
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6. Provide alarms on certain error conditions.
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7. Provide alarms on certain error conditions.
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Many pronounce UPS as "ups", but most of the literature seems to favor "you
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pee ess", since they use "a UPS" instead of "an UPS". This document will try
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to follow the literature. Neither pronunciation will get you laughed at by
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those who are experienced in the field.
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-----------------------------------------------------------------------------
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3. UPS Basics
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3.1. How To Select A UPS
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UPSes are nowadays very inexpensive. In the U.S. in 2006, quite capable ones
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are available for less than $100, and prices are heading down. In fact prices
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are so low now that we're not going to walk you through the elaborate
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optimization step that would have been important even two or three years ago,
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of estiming the watt dissipation of your computer and matching it to a UPS
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rating. Instead we'll explain why this would be a waste of effort and how to
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buy in a simpler and more effective way.
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Warning Bear in mind that the UPS systems that you're likely to buy in a
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store or computer catalog are not intended for safety or
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life-critical equipment. These devices should be considered to be
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pieces of consumer electronics. As such, the number-one basis on
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which most of these devices compete with each other is on price, not
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quality.
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Cost-effectiveness is more important to UPS vendors (because it
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appears to be more important to their customers) than ultimate
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reliability. If your life depends on computer uptime, you need a
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special purpose, online, big, redundant, expensive system. These
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systems are beyond the scope of this document. When you buy a UPS at
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your local computer store, you are not buying this sort of system.
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UPSes are rated by the watts a full battery can put out before it drains.
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However, they are marketed using a VA (voltage-amps) figure; often,
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consumer-grade UPSes don't even specify a wattage on the box where you can
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see it. This is because the VA figure is larger and looks sexier. As a rule
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of thumb. assume the wattage is half of the VA rating; for an explanation of
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the complexities involved (if you care) see the white paper Understanding
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Power Factor, Crest Factor, and Surge Factor on the APC website.
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But even if you know the watt rating of the UPS, it is the ratio of that
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figure with the wattage dissipation of your computer that controls the dwell
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time. Your dissipation is hard to predict; it can even be effected by things
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like the size of monitor you use (big ones can be quite power-hungry).
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Manufacturers try to get around this technical thicket by putting an expected
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dwell time on the box. But they exaggerate and even lie about their dwell
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times a lot (this is called "marketing"). What they'll do is quote you the
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dwell time you would get driving a bare minimum system with the disk drives
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shut off and a tiny monitor, in much the same way laptop manufacturers lie
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about their battery dwell times. The more honest UPS manufacturers give you a
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little table showing expected dwell times for different system configurations
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("desktop", "tower", etc.). As a rule of thumb, assume you will get about 50%
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of the dwell time listed on the box for your configuration type.
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My advice is to forget the numbers game. Just go online or to your local
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computer store and buy one of the higher-end consumer or home-office models
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from APC, Best, Tripp-Lite, Belkin, or some other reputable manufacturer. Go
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ahead and grab the model with the longest dwell time, highest watt rating, or
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biggest VA number you can find; the premium for it is not likely to be more
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than $75 over the bargain-basement model. I guarantee you will feel very good
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about your decision not to pinch pennies come your first extended power
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outage.
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Perhaps a more compelling reason it is better to over-buy capacity rather
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than ending up with a UPS that is too weak for your power drain is that
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overstrained UPSes can fail in ugly ways, including catching fire and
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exploding.
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Be sure you get a line interactive UPS rather than the older standby or SPS
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type. The older technology doesn't actually filter your power through the
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battery, so you're not assured of good voltage conditioning. The main
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advantage of an SPS (low cost) has been eroded now that line-interactive
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UPSes are so inexpensive. There are other UPS types, but they are either
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obsolescent or targeted at large data-center installations. For a detailed
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discussion of the different UPS types, see The different types of UPS systems
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, a white paper on the APC site.
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Another important consideration is how your UPS will communicate with your
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computer. Do not buy a serial line UPS (one that communicates via an RS-232C
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cable). These are passing out of use in favor of UPS designs that use USB or
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Ethernet, for the very excellent reason that RS-232C interfaces are flaky,
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difficult to configure, and difficult to debug. Ethernet is overkill for this
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application; UPSes simply don't need that kind of bandwidth. We recommend
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sticking with USB, which is well-matched in price/performance to this job and
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relatively easy to troubleshoot.
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Until recently there was an important distinction between smart and dumb
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UPSes. Dumb UPSes did voltage-level signaling through individual pins; smart
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ones used the link as a primitive character channel and could pass more
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status information over it. But if you avoid RS232C UPSes you will never see
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a dumb one; indeed, it is likely that by the time you read this no dumb UPses
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will be in production any longer.
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Some UPSes advertise that they deliver a sinusoidal waveform. Those that
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don't may be delivering something more like a square wave or a very noisy
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sine wave. There are differing schools of thought about how important this
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is. One school of thought holds that one should always run equipment on the
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best approximation of sinusoidal input that one can, and that deviations
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produce harmonics which may either be interpreted as signal if they get
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through a power supply, or may actually damage the equipment. Another school
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holds that since almost all computers use switching-type power supplies,
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which only draw power at or near the peaks of the waveforms, the shape of the
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input power waveform is not important.
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Who's right? We don't know. Nick's opinion is that sinusoidal output is worth
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the extra money, especially for on-line UPS systems that continually provide
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their waveform to the computer; Eric is inclined to doubt it matters much
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with modern power supplies. If you don't know that your equipment has a
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switching-type power supply, you certainly might want to think twice before
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buying a low quality UPS.
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Personally, I (Eric) like APC UPSes (nether Eric nor Nick has any connection
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with the company). But this is not the kind of widget for which manufacturer
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makes a whole lot of difference as long as you stick with one of the
|
|||
|
reputable brands.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
3.2. Deploying your UPS and other devices: the total picture
|
|||
|
|
|||
|
Our recommendation for a production Unix environment is a configuration like
|
|||
|
the following:
|
|||
|
|
|||
|
1. An UPS for the computer system.
|
|||
|
|
|||
|
2. Surge suppression on all phone lines, and also on serial/parallel lines
|
|||
|
that leave the room.
|
|||
|
|
|||
|
3. Line conditioners on any devices not connected to the UPS. If you do take
|
|||
|
a power hit, it's cheaper to replace a $50 line conditioner than a $1500
|
|||
|
laser printer.
|
|||
|
|
|||
|
|
|||
|
If this is too expensive for you, then downgrade the UPS to a line
|
|||
|
conditioner like the TrippLite. But don't go without at least that. Running
|
|||
|
unprotected is false economy, because you will lose equipment to electrical
|
|||
|
storms ?? and, Murphy's Law being what it is, you will always get hit at the
|
|||
|
worst possible time.
|
|||
|
|
|||
|
One thing to note is that you typically shouldn't put a laser printer on the
|
|||
|
brownout-protected sockets in a UPS ?? toner heaters draw enough current to
|
|||
|
overload a UPS and cause a shutdown within seconds. Modern UPSes generally
|
|||
|
have some plugs that are marked surge-suppressed but not filtered through the
|
|||
|
battery; plug your printer into one of those.
|
|||
|
|
|||
|
A UPS should be wired directly to (or plugged directly into) the AC supply
|
|||
|
(i.e. a surge suppressor is neither required nor suggested between the wall
|
|||
|
and the UPS). In addition, a surge suppressor between the UPS and the
|
|||
|
equipment connected to it is redundant.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
3.3. Software Assistance
|
|||
|
|
|||
|
Your UPS communicates with your computer so it can gracefully shut the
|
|||
|
computer down when an outage has lasted too long for the battery to cope. In
|
|||
|
order for graceful shutdown to actually happen, your computer needs to have a
|
|||
|
background process ?? a daemon, in Unix terms ?? watching whatever messages
|
|||
|
come over the UPS cable for the one that says terminate. Then it needs to
|
|||
|
tell the operating system to shut down.
|
|||
|
|
|||
|
Your UPS probably comes with a CD full of such software. Throw it away, as
|
|||
|
(a) most of it will be useless bits written for Windows systems, and (b) in
|
|||
|
the unlikely event you get Linux software it will almost certainly be stale
|
|||
|
binaries for a version you don't run.
|
|||
|
|
|||
|
Back in the days of dumb serial-line UPses, there used to be about half a
|
|||
|
dozen different open-source UPS monitor daemons: apcd, dumbupsd, genpowerd.
|
|||
|
powerd, smupsd, usvd and more. These were fairly stupid programs for a simple
|
|||
|
job. Many required you to hand-wire a custom RS232C cable to get around
|
|||
|
various evil things that UPS manufacturers did to their ports in order to
|
|||
|
lock in customers.
|
|||
|
|
|||
|
Those days are gone. USB UPSes get rid of the cable-hacking and hardware
|
|||
|
klugery, but require a bit more smarts from a monitor daemon. Accordingly the
|
|||
|
field has narrowed considerably. There appear to be only two such projects
|
|||
|
left standing.
|
|||
|
|
|||
|
The Network UPS Tools project is a generic UPS monitor daemon that aims to
|
|||
|
communicate intelligently with all current UPS designs.
|
|||
|
|
|||
|
[http://www.apcupsd.org/] apcupsd is a daemon specifically designed for
|
|||
|
communicating with UPSes made by APC, the American Power Corporation.
|
|||
|
|
|||
|
Both are solid, well-run projects. Their development groups are mutually
|
|||
|
friendly, and there has been occasional talk of a merger. Awkwardly, the
|
|||
|
apcupsd project is in many ways the more featureful of the two, with, among
|
|||
|
other things, better USB support and better documentation ?? but the NUT
|
|||
|
tools have a cleaner architecture, more developers, and acceptance in Red Hat
|
|||
|
and other major distributions.
|
|||
|
|
|||
|
My advice is simple; run apcupsd if you buy an APC UPS, and the NUT tools if
|
|||
|
you buy anything else. RPMs and Debian packages (which will modify your
|
|||
|
system's boot sequence appropriately as well as installing the daemon
|
|||
|
binaries) are available for both, so installation should be easy either way.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
3.4. Preparing Your System For Auto-Reboot
|
|||
|
|
|||
|
If you are using your UPS to try to keep a DNS/Web/mailserver up 24/7, you
|
|||
|
will want to make sure the machine can be configured to boot automatically
|
|||
|
when it is powered up.
|
|||
|
|
|||
|
This is not the normal behavior of most computers as shipped from the
|
|||
|
factory. Normally after the power is cut and restored, you must explicitly
|
|||
|
press a button for the power to actually be turned on. You can test your
|
|||
|
computer by powering it down; shutting off the power (pull the plug); then
|
|||
|
plugging the cord back in. If your computer immediately starts up, good.
|
|||
|
There is nothing more to do.
|
|||
|
|
|||
|
If your computer does not start up, manually turn on the power (by pressing
|
|||
|
the power on button) and enter your computer's SETUP program (often by
|
|||
|
pressing DEL during the power up sequence; sometimes by pressing F10). You
|
|||
|
must then find and change the appropriate configuration parameter to permit
|
|||
|
instant power on.
|
|||
|
|
|||
|
Normally, this is located under the BOOT menu item, and will be called
|
|||
|
something such as Restore on AC/Power Loss or Full-On. The exact words will
|
|||
|
vary according to the ROM BIOS provider. Generally you will have three
|
|||
|
options: Last State, Power On, and Power Off.
|
|||
|
|
|||
|
Some BIOSes do not support such an option. This is idiotically bad design,
|
|||
|
but it does happen. If so, your only practical remedy is to get a new
|
|||
|
motherboard.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
4. Testing Your UPS
|
|||
|
|
|||
|
To test your UPS, throw the circuit breaker with the UPS on it to simulate
|
|||
|
and outage and see how the transition goes. Note that in general testing an
|
|||
|
UPS by pulling the plug from the wall is not a good idea. Electronics like to
|
|||
|
always have a good ground reference. If you unplug a UPS, it's still powered
|
|||
|
but now has what electricians call a "floating ground". Not only can this be
|
|||
|
bad for electronics, but it can be quite dangerous as well. It is likely that
|
|||
|
unplugging just about any UPS for a short amount of time isn't likely to
|
|||
|
result in disaster (don't take our word for it, though!), but in all cases,
|
|||
|
throwing a circuit breaker would be a better thing to do.
|
|||
|
|
|||
|
It might be useful to install a GFI (Ground Fault Interrupter) on your
|
|||
|
UPS-covered outlets to facilitate this testing without having to throw a
|
|||
|
breaker, especially if you don't have your UPS protected machines on an
|
|||
|
isolated circuit (which you probably should). These are the sockets found in
|
|||
|
most modern kitchens and bathrooms with a red and a black button. You push
|
|||
|
the latter to cut power and the former to restore power.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5. Maintaining Your UPS
|
|||
|
|
|||
|
Make sure the UPS keeps in contact with its electrical ground at all times.
|
|||
|
Don't overload it. If it shows signs of misbehavior or malfunction, yank it
|
|||
|
until it's repaired, or replace it.
|
|||
|
|
|||
|
Your UPS has a battery inside it. Usually it is a lead-acid type (those are
|
|||
|
the least expensive for the manufacturer), but both lithium and gel-cel
|
|||
|
batteries are sometimes used.
|
|||
|
|
|||
|
The battery is by far the most vulnerable and failure-prone part of your UPS.
|
|||
|
If you have your UPS long enough, you will probably have battery problems.
|
|||
|
Once every six months to a year or so you should recalibrate your UPS's
|
|||
|
battery sensor, and once every several years you will have to replace the
|
|||
|
batteries.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5.1. Service contracts
|
|||
|
|
|||
|
Some consumer-grade UPSes, and all UPSes designed for serious data-center
|
|||
|
use, can be bought with vendor service contracts. These don't make sense for
|
|||
|
low-end units that can be replaced cheaply from a local electronics store. If
|
|||
|
you're an IT shop with a bunch of UPSes scattered over a campus, a service
|
|||
|
contract might make sense, depending on circumstances. If you have a larger
|
|||
|
UPS in the 5-10 KVA range, a service contract may be a valuable hedge against
|
|||
|
extended downtime.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5.2. Extending battery life
|
|||
|
|
|||
|
To extend your battery life, (a) avoid deep discharges, and (b) don't expose
|
|||
|
them to extremes of heat, cold, or humidity. Unfortunately there is not much
|
|||
|
you can do to avoid deep-discharging your UPS other than living in an area
|
|||
|
where power outages are few and short.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5.3. Recalibrating Your UPS
|
|||
|
|
|||
|
Your UPS's dwell-time calibration will lose accuracy over the life of the
|
|||
|
battery. The usual symptom of this problem is that the UPS overestimates the
|
|||
|
dwell time it has remaining during outages, but occasionally it can also lead
|
|||
|
to an actual bad-battery condition going undetected and very odd symptoms as
|
|||
|
a result.
|
|||
|
|
|||
|
UPSes have a recalibration procedure built into their firmware. It generally
|
|||
|
involves deep-discharching and recharging the battery while the UPS is in a
|
|||
|
special test mode. Your recipe for triggering such a recalibration will vary
|
|||
|
according to your UPS software.
|
|||
|
|
|||
|
You always need to do this when you install new batteries (see below). It is
|
|||
|
a good idea to do it once every six to twelve months as routine maintenance,
|
|||
|
but no more often than that; as we noted previously, deep discharges shorten
|
|||
|
your battery life.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5.4. Replacing Your Batteries
|
|||
|
|
|||
|
All modern UPSes have a low-battery alarm and run a periodic self-test; they
|
|||
|
will alert you when replacement is needed. Usually they both flash an
|
|||
|
indicator and make an alarm sound. If you have a monitoring daemon set up,
|
|||
|
they will alert it and you will probably get warning mail. If you ignore the
|
|||
|
alarm it will time out, but be repeated at intervals.
|
|||
|
|
|||
|
You will occasionally get a false alarm. It's a good idea, if you get an
|
|||
|
alarm, to explicitly trigger a UPS self-test the next day and see if the
|
|||
|
alarm goes away (the procedure for doing this varies depending on your UPS
|
|||
|
software). If the alarm is persistent, you need to replace the batteries.
|
|||
|
|
|||
|
It has been reported that bad batteries can also produce symptoms that mimic
|
|||
|
inverter failures or wonky control electronics. Even if your UPS is
|
|||
|
displaying epileptic symptoms like repeating alarms and flashing panel
|
|||
|
lights, a bad battery is the first thing to suspect.
|
|||
|
|
|||
|
UPS manufacturers would of course prefer that you replace your entire UPS
|
|||
|
when the batteries die, since they make more money that way. But in fact
|
|||
|
there is nothing unique or magic about UPS batteries. They are standard types
|
|||
|
also used for other applications such as powering marine electronics, with
|
|||
|
standard connectors. You can buy them from sources other than the UPS
|
|||
|
manufacturer, and sometimes replace them with equivalents that are better and
|
|||
|
less expensive.
|
|||
|
|
|||
|
It's best to wait until the low battery alarm before ordering a replacement;
|
|||
|
keeping batteries on the shelf reduces their life unless you keep them fully
|
|||
|
charged.
|
|||
|
|
|||
|
Do not throw old batteries in your regular trash! They contain toxic metals
|
|||
|
and acids. Be kind to your environment and hand them to a qualified party for
|
|||
|
recycling. Most battery dealers will cheerfully do this for you. If not, your
|
|||
|
local garbage company or waste-disposal authority can explain to you how and
|
|||
|
where to turn them in safely.
|
|||
|
|
|||
|
Many UPS models use gel-cel batteries in standard formats like 12.0 V, 7.2Ah
|
|||
|
(151x64x94 mm). Warning: Many manufactors sell two or three different types:
|
|||
|
standard use, cyclic use and high-current use. UPSes require high-current and
|
|||
|
some UPS don't work well with batteries for standard use, because the voltage
|
|||
|
goes low too early under high load (the UPS turns off too fast or the output
|
|||
|
voltage drops so that the computer turns off). Standard batteries are for
|
|||
|
alarm devices, emergency lights or things like that. For instance Panasonic
|
|||
|
sells the "LCR127R2PG1" (standard), and "UPRW1245P1" (high current), Fiamm
|
|||
|
the "FG20271" (standard) and "FGH20902" (high current), CSB the "GP1272"
|
|||
|
(standard) and "HR 1234W" (high current).
|
|||
|
|
|||
|
Below, you will find some suggestions for buying replacement batteries. One
|
|||
|
important note of caution: at least one user purchased one of the aftermarket
|
|||
|
batteries noted below and found out that they would not fit into his unit.
|
|||
|
This required cutting and soldering and other very undesirable things, so be
|
|||
|
extremely careful in measuring your batteries ?? including every millimeter
|
|||
|
of the terminal connections, which can cause problems.
|
|||
|
|
|||
|
Although you can do a hot swap of your batteries while the computer is
|
|||
|
running, it may not be very satisfactory, because the unit will not know that
|
|||
|
the batteries have been swapped and your monitor daemon will continue to show
|
|||
|
a low-battery indication. To correct this situation, you must do a discharge
|
|||
|
and recharge of the battery. At that point the battery should be calibrated
|
|||
|
better.
|
|||
|
|
|||
|
It may take several discharges and recharges of new batteries before they
|
|||
|
reach full capacity and the dwell-time calibration is accurate. If your UPS
|
|||
|
contains two or more battery units and your monitoring software reports
|
|||
|
separate voltage levels for them, one way to tell is to watch the divergence
|
|||
|
in voltage levels. As the cells reach nominal full capacity, their voltages
|
|||
|
should converge.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
5.5. Buying Batteries
|
|||
|
|
|||
|
APC makes "Replacement Battery Units" for each of the SmartUPS models, but
|
|||
|
they sell them directly only in the U.S. Your local Yamaha SeaDoo shop (if
|
|||
|
you have one) carries 35 ampere-hour deep cycle marine batteries that are
|
|||
|
direct replacements for the kind APC uses in many of its models. These are
|
|||
|
gel-cel and will double the runtime and/or cut your recharge time in half.
|
|||
|
Here are some West Coast sources:
|
|||
|
Jet Works
|
|||
|
1587 Monrovia Ave.
|
|||
|
Newport Beach CA 9266?
|
|||
|
Tel: +1 714 548-5259
|
|||
|
|
|||
|
J-W Batteries, Inc.
|
|||
|
Tel: +1 714 548-4017
|
|||
|
|
|||
|
WPS 49-1200
|
|||
|
GEL-CELL KB-35 BATTERY
|
|||
|
|
|||
|
The company I've heard most strongly recommended (by Carl Erhorn, a core
|
|||
|
developer on the apcupsd project) is called Battery Wholesale Distributors of
|
|||
|
Georgetown, Texas. If you have questions, you can reach them by phone at
|
|||
|
(800) 365-8444, 9:00AM to 5:00PM (their local time), Monday through Friday.
|
|||
|
Carl reports having gotten email from them on the weekends, although the
|
|||
|
office is not open then.
|
|||
|
|
|||
|
The web site, with current pricing, is [http://www.batterywholesale.com]
|
|||
|
www.batterywholesale.com. They will ship outside of the US, they take all the
|
|||
|
usual credit cards, and they accept orders by phone or Web.
|
|||
|
|
|||
|
Carl reports that BWD has found manufacturers who make batteries in the
|
|||
|
standard case sizes, but have additional capacity over original UPS
|
|||
|
batteries. Often, the difference is as much as 15% or so, and this can result
|
|||
|
in additional runtime. It's a nice upgrade for a minor increase in price.
|
|||
|
|
|||
|
BWD is also 'green-aware', in that they encourage you to recycle your old
|
|||
|
batteries, and will accept the old batteries back from you if you cannot find
|
|||
|
a local place that recycles them. You pay the shipping but other than that,
|
|||
|
there is no charge.
|
|||
|
|
|||
|
Carl says "I've been very pleased with their products, service, and pricing.
|
|||
|
I hope you find them as helpful to you as I do. I've been dealing with them
|
|||
|
since about 1994, and have never been disappointed. The owner of the place
|
|||
|
also is very good on technical issues, so if you have questions on their
|
|||
|
products, he can get as technical as you need to go."
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
6. Vendor information
|
|||
|
|
|||
|
Note: Many of these manufacturers make specialty systems for large data
|
|||
|
centers, not the consumer-grade UPSes that we cover in most of the rest of
|
|||
|
this document.
|
|||
|
|
|||
|
[http://www.apcc.com/] American Power Conversion
|
|||
|
APC is the largest manufacturer of small UPSes (<2000 VA) and has a
|
|||
|
whole line of UPS systems (mostly line interactive), software, and power
|
|||
|
system accessories which can be purchased directly from them or via many
|
|||
|
retail outlets around the United States and overseas.
|
|||
|
|
|||
|
[http://www.belkin.com/index.asp] Belkin
|
|||
|
Belkin makes a lot of computer connectivity products, including UPSes.
|
|||
|
|
|||
|
[http://www.clary.com] Clary Corporation
|
|||
|
Clary sells UPS products and specializes in emergency, military, and
|
|||
|
life support systems. They also sell management software and accessories.
|
|||
|
|
|||
|
[http://www.controlledpwr.com/] Controlled Power Company
|
|||
|
Controlled Power produces UPS systems, power conditioners, voltage
|
|||
|
regulators and transformers. Equipment can be ordered direct.
|
|||
|
|
|||
|
[http://www.powerware.com/USA/default.asp] Eaton Powerware
|
|||
|
Eaton Powerware includes the product line that was formerly Best Power,
|
|||
|
Inc.. They produce many types of UPS systems. more advanced line
|
|||
|
interactive systems, and ferroresonant line interactive systems as well
|
|||
|
as software, PDUs, and power system accessories.
|
|||
|
|
|||
|
[http://www.gotoemerson.com/main/default.asp] Emerson Electronics
|
|||
|
Emerson is a big electronics conglomerate. Its claim to fame in the UPS
|
|||
|
world is that it's the parent company to Liebert.
|
|||
|
|
|||
|
[http://www.powersource.net/] Energy Technologies, Inc.
|
|||
|
Energy Technologies provides power devices (including UPSes) for
|
|||
|
physically demanding customers, including military and vehicle uses. Most
|
|||
|
if their UPS systems seem to fall in the 600 to 6000 VA range.
|
|||
|
|
|||
|
[http://www.exide.com] Exide Electronics
|
|||
|
One of the bigger players in the data center sized UPS system industry,
|
|||
|
Exide also makes more modest sized on-line and line interactive systems.
|
|||
|
Exide products can be purchased direct or from their distributors.
|
|||
|
|
|||
|
[http://www.gamatronic.com/] Gamatronic Electronic Industris, Ltd.
|
|||
|
We're told these guys are the largest UPS manufacturer in Israel and
|
|||
|
the Middle East. Their product line runs the gammut from 1000 VA to 150
|
|||
|
kVA systems.
|
|||
|
|
|||
|
[http://www.geindustrial.com/industrialsystems/gede/index.html] General
|
|||
|
Electric Industrial Systems
|
|||
|
Yup, GE makes UPSes from 300 VA up to MVA systems.
|
|||
|
|
|||
|
[http://www.intellipower.com] IntelliPower, Inc.
|
|||
|
Intellipower sells on-line UPS systems and management software.
|
|||
|
|
|||
|
[http://www.liebert.com/] Liebert
|
|||
|
A subsidiary of Emerson Electronics (see above), Liebert is probably
|
|||
|
the largest manufacturer of large (10 kVA +) UPS systems. Also well known
|
|||
|
for their other data center products including power distribution units
|
|||
|
and HVAC products. They also make smaller UPS systems (300 VA on up), but
|
|||
|
these are not nearly as popular.
|
|||
|
|
|||
|
[http://www.mgeups.com] MGE UPS Systems
|
|||
|
MGE UPS Systems sells UPS systems from 300 VA to the very large and
|
|||
|
additional power equipment.
|
|||
|
|
|||
|
[http://www.meau.com/eprise/main/Home/home] Mitsubishi Electric Automation
|
|||
|
Mitsubishi Electric Automation seems to specialize in larger (> 5 kVA)
|
|||
|
UPSes, but they make them as small as 1 kVA.
|
|||
|
|
|||
|
[http://www.oneac.com/home.asp] Oneac
|
|||
|
Oneac sells line interactive and online UPS systems with software in
|
|||
|
the US and UK. They were acquired by the Chloride Group (see Chloride
|
|||
|
Power, below) in 1998.
|
|||
|
|
|||
|
[http://www.opti-ups.com/] OPTI-UPS
|
|||
|
OPTI-UPS makes standby, line-interactive, and online UPS systems
|
|||
|
ranging from 375 VA to 8000 VA.
|
|||
|
|
|||
|
[http://www.philtek.com/] Philtek
|
|||
|
Philtek makes inverters and other similar power system components.
|
|||
|
|
|||
|
[http://www.waber.com/] SL Waber
|
|||
|
SL Waber sells mostly UPS systems including the Tripp Lite brand name
|
|||
|
as well as a wide assortment of surge suppression and other power
|
|||
|
accessories.
|
|||
|
|
|||
|
[http://www.toshiba.com/] Toshiba
|
|||
|
Toshiba sells a lot of things, including UPSes. They sell online UPSes
|
|||
|
from 1400 VA to the 300 kVA range. One of Toshiba's product lines are
|
|||
|
UPSes specially designed to automatically configure themselves to work
|
|||
|
with both US (60 Hz) and European (50 Hz) power.
|
|||
|
|
|||
|
[http://www.p3international.com/] P3 International
|
|||
|
P3 International makes a number of cool consumer electronics devices,
|
|||
|
but as far as this document is concerned, the most interesting is an
|
|||
|
easy-to-use and relatively inexpensive power monitoring device called
|
|||
|
"Kill A Watt". When you can't or don't want to use a good break-out cable
|
|||
|
and ammeter, this device is a good choice for measuring power
|
|||
|
consumption.
|
|||
|
|
|||
|
[http://www.power-innovations.com/] Power Innovations International, Inc.
|
|||
|
Power Innovations sells online UPS systems ranging from 500 VA to 400
|
|||
|
kVA.
|
|||
|
|
|||
|
[http://www.chloridepower.com/] Chloride Power
|
|||
|
Chloride Power is a relative newcomer to the U.S. market but has much
|
|||
|
more experience and is better known in Europe. For the US market Chloride
|
|||
|
produces online UPS from the 700 VA to 3000 kVA range, and what look like
|
|||
|
they might be standby systems from 300 VA to 650 VA.
|
|||
|
|
|||
|
|
|||
|
There are a lot of companies in this space, and there's no way that we can
|
|||
|
list all of them. We try to include most of the best known companies along
|
|||
|
with a few niche players that might be of interest to the readers of this
|
|||
|
document. Let me know if there are important companies that we haven't
|
|||
|
included.
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
|
|||
|
7. Bibliography
|
|||
|
|
|||
|
One critical source of information on power protection is the IEEE "color
|
|||
|
book" series, especially the following:
|
|||
|
|
|||
|
<EFBFBD><EFBFBD>*<2A>The Emerald Book, IEEE Recommeded Practice for Powering and Grounding
|
|||
|
Electronic Equipment, Std. 1100-1999, 1999.
|
|||
|
|
|||
|
<EFBFBD><EFBFBD>*<2A>The Gold Book, IEEE Recommended Practice for the Design of Reliable
|
|||
|
Industrial and Commercial Power Systems, Std. 493-1997, 1997.
|
|||
|
|
|||
|
<EFBFBD><EFBFBD>*<2A>The Green Book, IEEE Recommended Practice for Grounding of Industrial and
|
|||
|
Commercial Power Systems, Std. 241-1990, 1990.
|
|||
|
|
|||
|
|
|||
|
-----------------------------------------------------------------------------
|
|||
|
8. Acknowledgements and Related Resources
|
|||
|
|
|||
|
Substantial portions of this document, notably the bits on maintaining your
|
|||
|
UPS, were originally part of the apcupsd documentation. The project
|
|||
|
maintainers have graciously permitted me to re-use them here. Other parts
|
|||
|
were part of my Unix Hardware Buyer HOWTO.
|
|||
|
|
|||
|
There was a previous UPS HOWTO by Harvey J. Stein, last updated in 1997. It
|
|||
|
was so out of date that I ended up using none of it.
|