help finding an uninterruptible power supply

[goodmanx]

we've finally decided that this would be a worthwhile investment to save potential loss of equipment and need to determine our needs. i'm not nearly as concerned with saving work in process at the time of a failure or surge as i am about protecting our equipment from damage from such an event.

my very limited understanding is that the wattage (voltage?) of the ups is of primary importance, such that the load the ups will be expected to bear must be roughly determined; please disabuse me of this notion if i'm wrong. we currently have a macbook, 22" monitor, a printer, cable modem, airport extreme, 8-port switch, cannon lide scanner (usb powered) and at least two external hard drives, one of which is attached to the airport extreme, powered up all the time. we also have a 7-port usb hub to which no drives are attached, though the printer and scanner are attached to it. my best (uneducated) guess is that the hub and switch, both of which are relatively inexpensive to replace, won't need to be plugged into the ups, but does their connection to the laptop and router, respectively, make protecting them important?

am i leaving out any important info?

i've started looking by going to this site: http://www.amazon.com/s/ref=nb_sb_ss_i_0...lias%3Daps&field-keywords=uninterruptible+power+supply&sprefix=uninterr%2Caps%2C257. of course, we'd rather spend less than more, but we do want to protect our stuff.

we'll appreciate y'all's getting us started here, along with any knowledgeable recommendations.

[Speedy]

APC has a calculator on its site. Plug it all into the UPS.

[JoeH]

First thing is to decide which items should be on the UPS, the rest can stay on surge protectors. At least part of your list I would leave off a UPS, for instance the printer and scanner. Also, given your statement:

i'm not nearly as concerned with saving work in process at the time of a failure or surge as i am about protecting our equipment from damage from such an event.

that goal could be almost entirely met with just surge protectors. The reason for using an UPS is to allow enough time to either ride out a short power loss or shutdown systems gracefully and save work.

With that in mind, if files are going to be saved over a network connection, that equipment should be on an UPS. The computer having its own battery might not need to be connected, but the external drives should be. As for capacity, most UPS's are listed by VA and may list the maximum wattage that can be drawn separately in the full specs. If that is not listed, you can estimate the wattage as being about 60-70% of the VA number. Normally you would want to keep the actual load to about half the maximum for a reasonable run time, but can go higher if all you want is a few minutes to shut down the connected equipment.

[Bill in NC]

Your first surge protector should be at the meter.

[westom]

goodmanx wrote:
i'm not nearly as concerned with saving work in process at the time of a failure or surge as i am about protecting our equipment from damage from such an event.

A UPS is for protecting unsaved data. If it protects hardware, then the electrical anomaly that harms hardware. That must be protected from. The problem must be defined before a solution can be discussed.

A typical UPS connects electronics directly to AC mains. Switches to battery only when AC mains power is lost. (A short period of no power exists during the switchover.) Larger spikes occur when a UPS is in battery backup mode. For example, this 120 volt UPS outputs spikes of up to 270 volts.

270 volts? Perfectly acceptable to all electronics due to superior protection existing and required to be inside electronics. That UPS is doing its primary function. To provide temporary and 'dirty' power during a blackout.

An AC utility demonstrates same in "Standby Power Supplies Can Lock Up Your PC":
http://www.duke-energy.com/indiana-busin...tip-03.asp

Another scoped his UPS. BTW, that is also called a pure sine wave output:
http://img260.imageshack.us/img260/8540/...50load.jpg


Sizing a UPS requires knowing consumption of the load. For example, a typical desktop computer most consumes less than 200 watts and rarely more than 350 (even with an 800 watt power supply). So a more than 350 watt UPS is required. But a UPS battery is typically good for three years. So that UPS is best sized so that its degraded battery can still provide sufficient power three years later. IOW a 500 watt UPS is probably necessary due to battery degradation (and other reasons).

Those waveforms say why a UPS is not recommended for motorized appliances (ie laser printer). Electronics make dirty power irrelevant, But small motors (and power strip protectors) can be harmed by a 'dirty' UPS output.

[Robert M]

Westom,

Some useful information in your post. Some info that I take issue with such as how to determine the appropriate UPS for the load you have on it. you didn't account for upgrades, additional devices and for duration of the outage. Each plays an important role when choosing the appropriately sized UPS for the job.

You've touched on the difference between standby models (very common) and online models. Here is a good white paper that describes it better than I:



For our purposes, here, I'd think of standard standby models and line-interactive models, i.e. APC Backup UPSs vs APC SMARTups models. The cheap UPSs that are very common at places like Staples and such are standby models. The better standby models also include automatic voltage regulation (AVR) which resolve the voltage issue you described. Think in terms of the APC Backups and Backups Pro models. The more expensive models also available from places like Staples and such are often line-interactive models such as the APC SMARTups series.

The info you provided about the type of output is very unclear. You're describing the difference between step-wave and sine-wave output. UPSs with sine-wave output have always been preferable. Good clean a/c output is sine wave output. The UPSs you commonly see are usually standby models with step-wave output. APC Backups XXXXX series and Backups Pro XXXXXX series are almost always step-wave models. Some can be had with AVR.

UPSs with sine-wave output have always been preferable to models with step-wave. Has been for years. However, models with sine-wave output tend to be line-interactive units or units that are on the next step up from that type. Line-interactive models are very expensive when compared to their standby cousins and oftne overkill for home, home office and even small office usage. I suspect one of the reasons why Cyberpower is making standby models with sine-wave output is because more and more people want sine-wave models but don't necessarily neither need nor can afford a line-interactive UPS like the SMARTups series.

But, all that aside, dirty juice isn't the reason people shouldn't connect printers to UPSs. It's power draw. Laser printers can draw a tremendous amount of juice at times, enough to blow the UPSs. An inkjet printer may not be an issue but I wouldn't connect one to a UPS either. Power draw is the primary reason I tell people not to protect printers with a UPS. The other reason is need. People use printers as necessary. Some don't even turn on their printers until they're actually printing something on it. That and it's easy enough to print something at a later time and/or throw a doc onto a stick and being it elsewhere for printing.

Robert

[Robert M]

Goodman,

If your goal is to protect your equipment from electrical surges, then you want a quality surge protector. These don't come cheap. However, if you want something that'll protect your equipment during a brownout, power flicker, power outage and/or surge, then you want a quality UPS. The type and size of UPS is dependent upon your equipment and budget.

The Macbook is a non-issue since its got a battery. It'll keep going in the event you lose juice. The rest of the items on your list aren't power intensive except for possibly the monitor and the scanner and that depends on the type of monitor (CRT vs LCD) and scanner. Possibly.

I can't give you a size recommendation because of the unknown factors. However, look for these items:

1. You'll do fine with a standby model, i.e. APC Backups. Line-interactive models like a SMARTups series are overkill for the circumstances.

2. Make sure the unit has automatic voltage regulation. This helps clean the juice being sent to the devices. Common on many standby models but rare on the cheap low-end models. It's a worthwhile feature. Make sure the unit you purchase has it.

3. If possible, purchase one with sine-wave output. Not common on the lower end models from APC. Becoming more common these days. You'll likely find it on a Cyberpower model before you'll see it on APC models in a similar price range.

4. Make sure the UPS has ample outlets including space for wall wart style AC adapters. The number of outlets in general and, of those outlets, the number of battery/surge protected outlets vs surge only outlets can be an issue. The sheer number of items you want to protect may dictate to two or more smaller UPSs vs a single large UPS. For example, connect all of the networking equipment to one UPS. Connect the display and drives to the other UPS.

It won't matter which UPS has the Macbook since the computer has a battery already. I wouldn't worry about connecting the scanner to a battery/surge outlet since in the event of an outage, short or long term, I deem it unlikely you'll be doing anything with it. You'll be shutting down your hardware or stopping the scan and starting it again at a later time.

FWIW, most of my networking hardware is protected by three a Cyberpower 685va UPSs that have AVR. One has a switch and two vonage boxes, an HP all-in-one and my wife's HP laptop connected to it. The computer and printer are on surge only outlets. The rest on surge/battery backup outlets. The UPS is overkill for the job. The other has the FIOS modem, a Mac Mini and a Drobo connected to it. I wouldn't go less than 685 va because these need to be powered for as long as reasonably possible during an outage. The third has a MoCa adapter, FIOS DVR and Playstation 3 connected to it. For these items, I wouldn't go less than 685 va because some need to be powered for as long as reasonably possible during an outage.

None of the Cyberpower UPSs have sine-wave output, just step-wave. This is because at the time of purchase, UPSs with sine-wave output was prohibitively expensive. That and I didn't have the MAc Mini and Drobo at the time of purchase. Most of the stuff was readily replaceable at reasonable cost. However, as these UPSs wear out (and/or need new batteries), they will be replaced with models that offer sine-wave output.

My Mac Pro and display are protected by an APC SMARTups 1500 va. These are my most expensive pieces of hardware and not as readily replaced as the rest of my tech. That and both Apple and APC said the Mac Pro should be protected by a UPS that offers true sine-wave output. APC SMARTups models were the sine-wave output UPSs of choice at the time. So, I dropped the bucks for one of the big boys.

Hope that helps,

Robert

[westom]

Robert M wrote:
The info you provided about the type of output is very unclear. You're describing the difference between step-wave and sine-wave output. UPSs with sine-wave output have always been preferable. Good clean a/c output is sine wave output. The UPSs you commonly see are usually standby models with step-wave output.

First, described UPS (with a spike of up to 270 volts) is an APC. Little difference between a step wave and so called sine wave output. Because all outputs are nothing more than a sum of sine waves. All are sine wave outputs. APC will forget to mention that .

To say more requires a parameter such as %THD. But to keep a consumer naive, many UPS manufacturers (ie APC) avoid that 'always required' number. What is 'dirty' power? %THD in manufacturer specs define 'clean' or 'dirty'. Some 'cleanest' power is when AC mains connects directly through a UPS to the appliance.

Difference between step wave and sine wave is relevant only when a number is provided. I have a 120 volt UPS described in advertising as a sine wave output. It outputs 200 volt square waves with a spike of up to 270 volts. They did not lie. Even high school math says that square wave or stepped wave output is only a sum of pure sine waves. Advertising hopes many will forget what is taught in math.

Second, step wave output is not harmful to electronics. Also forgotten when advertising myths replace science. That 200 volt square wave with a spike is made irrelevant by how electronics are designed. Electronics, even long before the IBM PC existed, are that robust.

Third, power draw is the myth that says do not connect a laser printer to AC mains. A printer (or any other motorize appliance) draws so much power. A specific number. So a UPS need only be sized that large or larger.

But, a UPS with sufficient power is still not recommended. Why? Because UPS power can be so 'dirty'. Ie step wave. A UPS can output more than enough power for a motorized appliance (printer). But its 'dirty' power, ideal for electronics, is also potentially harmful to small motors.

Advertising must avoid that reality. So advertising blames a "power hungry" printer. Otherwise you might learn (first point) how 'dirty' a UPS really is when in battery backup mode. And then you might also learn (second point) how robust electronics really are.

So again, point four: what anomaly does the OP wish to solve? That must be defined long before any suggestion can be posted.

One anomaly is a surge. Most surges are already made irrelevant by superior protection inside appliances. Same protection that also makes irrelevant a 'dirty' UPS. Concern is one type of surge that can occur maybe once every seven years. If any computer needs that protection, then so does the furnace, bathroom GFCI, clocks, refrigerator, and dishwasher. What most needs protection from the typically destructive surge? Smoke detectors.

Bill in NC has defined what always exists in every facility so that a potentially destructive transients does not cause damage. And what is necessary to protect household appliances. A technology well proven and routinely installed even 100 years ago. And is why every telco operates $multi-million computers, connected to exposed overwhead wires, without threat. That anomaly requires something called a surge protector. Completely different from another device - also called a surge protector - located adjacent to the appliance.

But again, which electrical anomaly must be solved. A $100 protector from Monster is only electrically equivalent to one also selling in Walmart for $12. But again, the always required numbers. Monster knows that a majority will believe advertising or price rather than learn simple spec numbers and basic science.

Numbers such as %THD or joules are essential for any honest recommendation. Numbers that are relevant only when the anomaly is first defined. View surge protection numbers for a UPS. Even the $12 Walmart protector may claim superior protection.

And that is the point. Subjective claims such as 'pure sine wave' are best called hooey.

So again, which electrical anomaly is to be elminated? Due to superior protection already inside electronics, even 'dirtiest' power from a UPS is ideal power.

[Speedy]

Thanks!

[Robert M]

Westom,

I stand by what I've posted to this thread. You've actually supported much of what I clarified in my post the exception being the draw of a laser printer. I've seen UPSs blown by high draw hardware such as laser printers. That's good enough reason for me to connect them to a different protective device, i.e. dedicated surge protector rather than a UPS.

Robert