How to choose an uninteruptible powersupply?
Thread poster: Heike Holthaus

Heike Holthaus  Identity Verified
United States
Local time: 23:51
Member (2012)
German to English
+ ...
Apr 23, 2013

I am looking into buying an uninteruptible powersupply for 1 pc, monitor and printer. The goal is to be able to work through a power outage with power coming from a generator.

What do I need to look for? Would these do the job?
Or has anyone suggestions for a better UPS?

CyberPower CP850AVRLCD 850 VA 510 Watts 9 Outlets UPS
TRIPP LITE ECO ECO850LCD 850 VA 425 Watts 12 Outlets UPS with Enhanced LCD Interface and USB Monitoring Port, RJ11
Tripp Lite OMNI900LCD Omni Smart Digital 900 VA 475 Watts 8 Outlets Line Interactive UPS w/ LCD display

Thanks for your input.


Direct link Reply with quote
 

Tony M  Identity Verified
France
Local time: 05:51
Member
French to English
+ ...
Capacity rating Apr 23, 2013

What is most important for you is going to be the capacity rating, usualy expressed in Ah (= ampère-hours), which means in essence how long you can draw how much power from it.

I somehow think you may be optimistic to imagine you can run PC, screen, and printer for any length of time on a UPS available for an affordable price; my own aim would be to run the PC and screen just long enough to be able to save my work and shutdown cleanly.

I somehow thing much longer capacity than that is likely to be expensive, as would be supplying a (relatively) power-hungry printer.

Bear in mind that an office PC is likely to be running at somewhere around 500 W, and a monitor say 100 W — that means 600 W = approx. 2½ A (@ 230 V); so without taking the printer into account, you need to look at a capacity greater than 2.5 Ah to be able to run those two for an hour; of course real capacities are a lot higher than that, but dividing the unit's Ah capacity by 2½ should at least give you a ballpark idea of how long it might hold up for.


Direct link Reply with quote
 
Kevin Fulton  Identity Verified
United States
Local time: 23:51
German to English
UPS Apr 23, 2013

Most affordable uninterruptible power supplies only provide enough juice to allow you to finish a limited task, save your work, and shut down your computer in an orderly manner. If you have a power outage greater than about 15-20 minutes, you will not be able to work, as I've found out (I have an APS, can't read the model number as it's behind my desk). It is useful for momentary dropouts, however.

Direct link Reply with quote
 

Heike Holthaus  Identity Verified
United States
Local time: 23:51
Member (2012)
German to English
+ ...
TOPIC STARTER
UPS plus generator Apr 23, 2013

is the key. My understanding is, that a generator can cause damage to electronics because of "noise". Hence the UPS, but if choosing the wrong one, they may also be damaged.
The printer is only sometimes required. Most times I could do without.


Direct link Reply with quote
 

Meta Arkadia
Local time: 11:51
English to Indonesian
+ ...
Stabiliser Apr 23, 2013

Don't forget to buy one. A stabiliser, that is. Connect it between mains/generator and UPS.

Cheers,

Hans


Direct link Reply with quote
 

Rolf Keller
Germany
Local time: 05:51
English to German
The design principle is the key Apr 23, 2013

TranslatorHeike wrote:

My understanding is, that a generator can cause damage to electronics because of "noise". Hence the UPS, but if choosing the wrong one, they may also be damaged.


Additionally the PC may crash occasionally.

Generally there are 3 design principles but the names can differ:
see http://de.wikipedia.org/wiki/Unterbrechungsfreie_Stromversorgung
or http://en.wikipedia.org/wiki/Uninterruptible_power_supply

For what you are wanting to achieve you MUST buy a device with the second or (better but more expensive) third design.


Direct link Reply with quote
 

Rolf Keller
Germany
Local time: 05:51
English to German
Power? Apr 23, 2013

Tony M wrote:

What is most important for you is going to be the capacity rating, usualy expressed in Ah (= ampère-hours), which means in essence how long you can draw how much power from it.


Really? Actually the manufacturers seem to publish a time vs. wattage diagram. Which manufacturer specifies Ah?

Bear in mind that an office PC is likely to be running at somewhere around 500 W, and a monitor say 100 W


I disagree. An office PC without a gamer's graphic card should take less than 150 W, and a 21" flatscreen less than 40 W.


Direct link Reply with quote
 

Alma de Kok  Identity Verified
Poland
Local time: 05:51
Member (2006)
Polish to Dutch
+ ...
Internet + laptop Apr 24, 2013

I have a UPS (Lestar) TS 1100 and a backupsystem on a laptop with a long batterylife. When I have a power outage I back up my work from my main system on my laptop and use the UPS only for keeping internet running (I have internet via satellite Tooway, it works about 4-6 hours). Battery life of my laptop (Acer) is also about 4-6 hours. It happened only once I couldn't work (but only 10 minutes) before power returned.
The UPS also takes care of peaks and lows in the power supply (in the Polish countryside that's a rule....).

Alma


Direct link Reply with quote
 

Meta Arkadia
Local time: 11:51
English to Indonesian
+ ...
Yes but Apr 24, 2013

Alma de Kok wrote:
The UPS also takes care of peaks and lows in the power supply (in the Polish countryside that's a rule....)

It does, but once Heike has to switch on her generator, the "noise" may ruin her UPS, if not more. That's why I suggested the stabiliser. They are dirt cheap anyway, no reason not to buy one.

Here (Indonesia): Mains/generator | surge protector | stabiliser | UPS* | iMac 27"

*A Prolink 1200VA, maybe a bit excessive for one AiO, but it's only around USD 80.
http://www.alnect.net/products.php?/2/75/275/788/Accessories-Parts/Power-Sources-Batteries/UPS/UPS-Prolink-PRO1200S-1200VA

Cheers,

Hans


Direct link Reply with quote
 

Alex Lago  Identity Verified
Spain
Local time: 05:51
Member (2009)
English to Spanish
+ ...
Get a power pack Apr 25, 2013

You could always get a power pack, that should cover most of your needs

Here is one example:
http://www.goalzero.com/shop/p/19/Extreme-350-Power-Pack/2:8/


Direct link Reply with quote
 

Rolf Keller
Germany
Local time: 05:51
English to German
A power pack is no UPS Apr 26, 2013

Alex Lago wrote:

You could always get a power pack, that should cover most of your needs

Here is one example:
http://www.goalzero.com/shop/p/19/Extreme-350-Power-Pack/2:8/


This device is useless regarding Heike's needs. She wants & needs a so-called uninterruptable power supply device (UPS). The power pack you mentioned is no UPS, it is for use in environments where no ac outlet is available. Charge it at home, then take it to your garden and use your pc for one hour. Then go back home and charge again.

And, btw, this power pack needs an additional device (an inverter), because it can't deliver any AC voltage.


Direct link Reply with quote
 

Alex Lago  Identity Verified
Spain
Local time: 05:51
Member (2009)
English to Spanish
+ ...
Yes, but Apr 26, 2013

Rolf Keller wrote:

And, btw, this power pack needs an additional device (an inverter), because it can't deliver any AC voltage.


This model has an AC outlet and adding the inverter doesn't add much to the cost.

She said she wanted a UPS to work with a generator, that means the UPS will actually only work for a few minutes/seconds (depending on whether she has her generator set up to start automatically or not) as she didn't specify whether or not she already had the generator I assumed she did not (maybe she does).

If she does have a generator already then it doesn't really matter what UPS she buys as it will only have to keep the devices going while she turns on the generator, so any half-way-decent UPS will do. If she doesn't have a generator then she would have to buy one and they tend to be quite noisy so I though getting a power pack would be a quieter solution.

Obviously the generator would run for hours and a power pack won't but how often does her electricity go off for hours?


Direct link Reply with quote
 

Rolf Keller
Germany
Local time: 05:51
English to German
There is good and bad electricity Apr 26, 2013

Alex Lago wrote:

She said she wanted a UPS to work with a generator, that means the UPS will actually only work for a few minutes/seconds


She wrote: " My understanding is, that a generator can cause damage to electronics because of "noise". Hence the UPS ..."

The UPS will work all the time, filter the noise, and regulate the voltage, because generators are no precise devices. Generators have limited power, thus their voltage may exhibit heavy spikes when loads like refrigerators or cookers switch themselves on or off.

Is it really possible to switch the supply safely & on-the-fly from the power pack to the generator and vice versa? Without crashing Windows?

how often does her electricity go off for hours?


As Heike considers using a generator, there must be a reason. Some people live in houses/areas that have no reliable connection to a reliable grid. There are even houses with generators running all the time, e. g. small waterfall generators.


Direct link Reply with quote
 

Alex Lago  Identity Verified
Spain
Local time: 05:51
Member (2009)
English to Spanish
+ ...
That's true Apr 26, 2013

Rolf Keller wrote:

As Heike considers using a generator, there must be a reason. Some people live in houses/areas that have no reliable connection to a reliable grid. There are even houses with generators running all the time, e. g. small waterfall generators.



Very true


Direct link Reply with quote
 

Heike Holthaus  Identity Verified
United States
Local time: 23:51
Member (2012)
German to English
+ ...
TOPIC STARTER
Thank you all Apr 26, 2013

for offering your insight.

I do in fact have a generator, but I do not want to run the computer on it without any thing between the computer and the generator.

To the question about the power outages:

I live in rural Michigan and one would think this whole discussion shouldn't even have to happen. Unfortunately just this year alone we were without power 3 or 4 times and always between 1 and 2 days in length. So far I have not been caught in the middle of a project with a tight deadline, but it is always on my mind.

I will probably add the stabilizer, as t doesn't help if I fry my UPS:{.


Direct link Reply with quote
 


To report site rules violations or get help, contact a site moderator:


You can also contact site staff by submitting a support request »

How to choose an uninteruptible powersupply?

Advanced search






Protemos translation business management system
Create your account in minutes, and start working! 3-month trial for agencies, and free for freelancers!

The system lets you keep client/vendor database, with contacts and rates, manage projects and assign jobs to vendors, issue invoices, track payments, store and manage project files, generate business reports on turnover profit per client/manager etc.

More info »
memoQ translator pro
Kilgray's memoQ is the world's fastest developing integrated localization & translation environment rendering you more productive and efficient.

With our advanced file filters, unlimited language and advanced file support, memoQ translator pro has been designed for translators and reviewers who work on their own, with other translators or in team-based translation projects.

More info »



Forums
  • All of ProZ.com
  • Term search
  • Jobs
  • Forums
  • Multiple search