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Thread ID: 54680	2005-02-19 03:35:00	Uninterrupted Power Supply Recomendations?	CliveM (6007)	Press F1

Post ID	Timestamp	Content	User
326362	2005-02-19 03:35:00	Hi all I am considering purchasing a Uninterrupted Power Supply for my home office and would appreciate any expert opinion on what is/is not good currently on the market. I require something with enough grunt to handle my PC, Printer, Scanner, Fax machine and the usual associated bits and pieces. I would like at least 30 minutes and preferably an hour or two. Within the bounds of reason cost is of lesser importants than performance. I have had a look at Ascent,s offerings but find they do not give enough information to make a sensible choice without some prior knowledge of the items. Thanks in advance. :)	CliveM (6007)
326363	2005-02-19 03:54:00	Hi Clive It sounds like you want to be able to work on through any outage, but your list of appliances would require a large and quite expensive UPS. Most people settle for 650-1000 VA max, which will run the average computer and monitor long enough to complete the immediate task (say 10-15 minutes if you really want a printer attached) and carry out an orderly shutdown. You would probably get much longer than that out of a 1000 VA UPS, especially if you have an LCD monitor, but it is better to plan for the reserve capacity available 2-3 years down the line when the battery is not so hot anymore. Murphys law says you will never see an outage while everything is in tip top order, just like hard drives never seem to crash when your back ups are fully up to date. Can you define your requirements a little more, especially if they are mission-critical. Cheers Billy 8-{)	Billy T (70)
326364	2005-02-19 04:08:00	Without knowing the loading of the devices it's a bit of a guess. LCD screens require significantly less power than CRT for instance. But the hour or two is the real killer. Most UPS give a 5 minute window in which they shut the system down or allow you to do it manually. To have 30 minutes to 2 hours is a big step up from the common systems. It becomes more of a back-up supply in nature. You would probably need 750 - 1000 vA in UPS capacity. That is about 70 amps at 12 volts, after efficiencies are taken into account. That means for 2 hours it would have to have over 140 amp hour capacity of storage batteries (a large size car battery is 60 amp hours, a standard size is 45 amp hours as an indication) plus a charger sized to service the large battery bank. Is this along the lines of your needs? You may need to look at specialised power systems companies more than PC shops for the large system suggested. Beware attaching external batteries to smaller units not designed for them as well. The electronics is often designed in a manner (non-isolated) that means the battery is "alive" at 230 volts when the unit is active. You usually cannot easily extend the standby time of smaller units with larger batteries either as the electronics is not designed to run for long periods, it will overheat.	godfather (25)
326365	2005-02-19 04:32:00	Thanks for the prompt advice . My system is a P4 monitor is LCD . From what you seem to be suggesting I should be looking at spending around $1k . Whilst I wish to have a reasonable margin of safety without being paranoid so long as I can shut things down properly that could work . Perhaps just PC, Monitor and usb hub etc on the UPS and protect everything else through my current power surge protection . I had 4 power outages here last night and do not like them when in the middle of running a programme . Thanks again . Any brand recommendations?	CliveM (6007)
326366	2005-02-19 04:43:00	I had a quick look at Ascent's site and they do have a range of good quality UPS available . I use APC myself, but Liebert are also OK . I don't know much about the others . To assess your needs, add up the wattages of all the items you want to connect up, take the faceplate value for your PC power supply (e . g . 350 watts) so it is a worst case example, then multiply the result by 50% to get an approximate minimum VA rating . That is only the capacity of the UPS to supply the load current though, and says nothing about how long it will last during an outage . That depends on the battery capacity, so for the run-time specification you will have to refer to manufacturer's literature . I still think 1000VA is a minimum even if you don't load it up with the fax and the scanner . I can't see why you would need to scan during an outage, but I can appreciate that if you frequently do important scans, you might not want one interrupted . Cheers Billy 8-{)	Billy T (70)
326367	2005-02-19 04:54:00	Thanks again for your advice. Gives me an idea as to which way to go :thumbs:	CliveM (6007)
326368	2005-02-19 05:29:00	Agree with BT & GF, you don't normally plug printers and scanners into a UPS's battery powered backup outlets, but it's good practice to plug them into the UPS units surge protected outlets . Like Billy I have an APC 500VA ES and find rhis suits with a CRT monitor, scanner, printer and switch plugged into the power surge/conditioning otlets while the PC and adsl modem are plugged into the UPS side with phone/adsl also plugged in . When I researched the pro's and cons, I found that it was cheaper to purchase two 500VA units rather than one 1000VA (1 . 0KVA) and that this gave me far more outlets as well . Mine has never been overloaded . Look for units that come with auto save and graceful programme/OS shutdown software, phone/modem line protection and network protection if necessary . For a small office/home also look for user replaceable batteries . Crickets back on see u	Murray P (44)
326369	2005-02-19 06:04:00	Many thanks for everyones input! It is a lot cheaper to pick your brains than to try it all out on my own. :)	CliveM (6007)
326370	2005-02-19 06:44:00	I had 4 power outages here last night and do not like them when in the middle of running a programme. Why do you have so many outages?	sambaird (47)
326371	2005-02-19 08:46:00	Hi Sam Dont know. Any outage here is unusual. Probably some idiot ran a power pole over late yesterday. Cheers Clive Incidently it is about 50 years since anyone called me a junior member of anything. :)	CliveM (6007)
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