UPS questions for iMac

Discussion in 'iMac' started by CatAndTie, May 27, 2013.

  1. CatAndTie macrumors newbie

    Sep 9, 2011
    Hello all,

    I've tried doing some research to understand the technical terminology for UPS and surge protectors, etc, but am still kind of confused plus have a few extra questions. After researching a bit on Mac forums, it appears that most people recommend getting a UPS for protection, which I'm fine with. I'd rather have more of a safety net than none.

    1. I have a mid-2011 27" iMac, and would be running a few external hard drives and a printer with this UPS... so what kind of UPS would be sufficient?

    2. I just moved into an older house and my office has one outlet alllll the way across the other side of the room. To efficiently wrap a cord around the room, I would need about a 10-12 ft cable, but have not found any UPS with that length of cord. So, maybe the bigger question is this:

    How can I safely extend the UPS? Plug an extension cord from the wall to the UPS? Get extension cords for my Mac, printer, externals and run all of them around the room to the UPS? How about plugging the UPS directly into the wall, and then run a surge protector from that to the computer station?

    3. I don't want to drop 100 bucks on a box that I make obsolete or bypass by running extensions cords and what not. By running these cords would the UPS even function correctly?

    I just do not understand electric, surges, currents, etc enough to make a smart decision and need some advice!

    Thanks in advance, guys.
  2. Bear macrumors G3

    Jul 23, 2002
    Sol III - Terra
    Do not ever plug a surge suppressor in to a UPS.

    If you have to you can use a heavy duty extension cord from the UPS to the wall. Home Depot sells some nice very heavy duty extension cords in assorted lengths.

    As for how big a UPS, you didn't say how many external drives or what type of printer. Without that info it's difficult to correctly size the UPS. Also any USB hubs or external optical drives that would be in use as well? I also have my networking gear plugged in to my UPS.
  3. CatAndTie thread starter macrumors newbie

    Sep 9, 2011

    OK, let's see.
    Right now I will two 3 TB external drives potentially plugged in at the same time and an Epson Stylus NX 430 wireless ink jet printer, and my iMac, and maybe charging a camera, batteries, or a phone at some point I'm guessing, but the important ones are the iMac, HD's and printer of course.
    As of right now I do not have a USB hub and don't plan on getting one in the future (yet). I also do not have any external optical drives... but maybe will get some sort of blu ray writer drive in the future. Other than that, nothing yet. I might get another external hard drive though, but no plans right now.

    Is that sufficient info or do you need more?
  4. flynz4 macrumors 68040

    Aug 9, 2009
    Portland, OR
    I would put the iMac into the battery backed up side... as well as the HDDs. Everything else I would put on the surge protector side of the UPS. You didn't mention your internet connection (modem/router, etc)... but I would put them on the surge protector as well (since network traffic is resilient to data loss).

    Then I would set the iMac to shut down in plenty of time to be off before the battery goes dead. I use all 3 mechanisms (Time, %battery, %time) to trigger shutdown events. Sometimes a process might prevent a Mac from shutting down... and this gives me 3 chances. I let the HDDs run until the battery is exhausted... They will not be doing anything anyway with the computer off.

    My priority is to get the Mac shut down prior UPS battery depletion. My priority is NOT to keep the iMac running as long as possible.

  5. westom macrumors regular

    Nov 8, 2009
    Code says a wall receptacle must be withing 6 feet of any location on any wall. A receptacle every 12 feet of wall means no appliance needs a power cord longer than 6 feet. If the office has only one receptacle, then it does not meet human safety codes. That office needs one or more wall receptacles.
  6. CatAndTie thread starter macrumors newbie

    Sep 9, 2011
    Yeah, I know the code says every six feet, but this is an old farmhouse that definitely doesn't have one every six feet... At least not in the office. There is one close to where you walk in the door and that's it. And I set my computer up on the other side, and don't want a cord going straight across the center of the room.
  7. westom macrumors regular

    Nov 8, 2009
    So install another wall receptacle. Solves many problems including a human safety issue.
  8. skinny*k macrumors regular

    Feb 21, 2011
    CatAndTie, before you do anything else, I suggest that you check the electrical service panel of your house; when houses first began to be wired for electricity (back when one outlet per room was common) the service panels (the fuse- or breaker-box) were usually only rated for 60 Amps, which was enough for lighting and a radio. If you have common modern kitchen appliances, and more than a radio in the way of home entertainment, you are probably already maxing-out your service panel, and a UPS won’t prevent damage—or even a fire—to your house.

    If you have at least a 200 Amp box (and more is better), with circuit-breakers instead of fuses, you can disregard the rest of this post. :)

    If your fuse-box contains those old-fashioned glass fuses (the ones that screw into light-bulb sockets) and/or cartridge fuses (tubes with metal caps on the ends) have it checked out by an electrician; your electric utility company might even provide a free courtesy inspection. If you’re having problems with things acting-up, or blowing fuses, say when the refrigerator kicks in or you use the microwave or air-conditioner, have your service checked.

    If its that old, the house wiring might be in bad condition, too, and adding more outlets would only make things worse, safety-wise.

    In case you’re renting, and the landlord won’t allow expenditures, for about $100 (depending on how much wire you’ll need) you could get a sub-panel to run additional outlets from; everything that you’ll need to know about home wiring can be found in self-help books on the subject, and you can find them at hardware stores or your local library.

    Home wiring isn’t rocket science, but there are some things that are important to know; just don’t take any short-cuts—saving a few bucks could cost you everything that you own, including your iMac and new UPS.
  9. CatAndTie thread starter macrumors newbie

    Sep 9, 2011
    This room is literally the only room in the house that doesnt have multiple outlets. I have never had issues with circuit breakers being tripped or blowing fuses. I'll have to check out the electrical service panel though and see. I'd be shocked if it wasn't circuit breakers.
  10. CatAndTie thread starter macrumors newbie

    Sep 9, 2011
    Ok, just checked on it. Here's what I found...

    It was an old farmhouse that was converted to two apartments. Both sides do have a circuit breaker box (I have no idea where to find the amps?). The landlord (who used to live on my side) said he never had issues with circuits tripping.
    However, there is still a fuse box with two tube fuses marked for the other side of the house on our side right next to my circuit breaker box. Is it possible to set it up to have a circuit breaker and a fuse box at the same time or might it just be an obsolete box at this point?

    The fuses were each 60 amps, too if that makes a difference.
  11. westom macrumors regular

    Nov 8, 2009
    Relevant is what each fuse or circuit breaker (always have numbers) is for each circuit. Fuses and circuit breakers do same function. However humans like to replace a 20 amp fuse with a larger fuse. A biggest danger is previous humans - not the fuse or circuit breaker.

    A 20 amp circuit could have 7 15 amp receptacles on it. Obviously 15 times 7 means the circuit could easily be overloaded by more than 5 times. Adding an eight receptacle does not increase risk. That receptacle was recommended to protect human life from fire.

    So, what exactly is powered by those 60 amps fuses? Are they the main fuse? Or a fuse for one 15 amp or 20 amp circuit? Easy is to learn this. Disconnect each fuse and locate all 'no longer powered' receptacles, switches, and appliances. Only then can anyone post something that is useful - without wild speculation.

    As another noted, home wiring is so layman simple that all stuff is sold in Home Depot and Lowes. However layman also know to learn layman simple concepts before doing anything. For the same reason every informed auto driver knows what dashboard light report.

    It's a rental. You cannot install that receptacle. But any minimally intelligent landlord would immediately fix defective electrics if you offer to pay. Especially when this solution is so trivial and layman easy.

    Meanwhile, informed layman would learn whether those fuses are properly installed or grossly oversized (a potential house fire). Then that layman can go to any future house and know what he has. Any 'guy' knows this stuff. Described here is what any 'guy' does to be informed.
  12. CatAndTie thread starter macrumors newbie

    Sep 9, 2011

    I'll check it out tomorrow to see what the fuses are connected to. He thinks they are for his side, meaning my office here would not be affected.

    I thank you for your help, but not really sure what you are referring to with the whole "guy" conversation... I don't know crap when it comes to electricity issues and wouldn't really like to mess with it to find out.

    If these fuses are not related to my office then I'd like to refer back to the original question about the UPS and extension cords, etc if we can't get another outlet installed. I'd like to know all of the options here.
  13. westom macrumors regular

    Nov 8, 2009
    Every 'guy' eventually must learn these basics. Should you own your own place, you will be the 'only' person responsible for knowing whether a serious problem exists. For example, you should know (just from looking at that box) whether that 60 amp fuse is the main fuse or is for a circuit. If not, get a friend to show you. As a homeowner, you will be the only person responsible for inspecting some other simple connections that are essential to human safety.

    By viewing wires leaving each box (assuming you can see them), then you should know if each box serves separate apartments. Generally, apartments should have their own breaker box.

    It is not hard. Electricity concepts taught in elementary school are necessary. You should be able to view even an appliance plug to know if it is safe or not. For the same reason every driver views lights on an auto dashboard to know whether a serious or even dangerous fault exists.

    Back to the wall receptacle. Extension cords are only a temporary connection. However, if a receptacle does not exist within 6 feet of the appliance (receptacle every 12 feet), then a properly sized extension cord is necessary. In your case, a power cord (or power strip) must be three wire type. Should be UL listed. And routed so as to not cause tripping. If using a power strip, it must have a 15 amp fuse. More examples of simple concepts that, as a 'guy', you need to know to protect any future family or home. And need to know why.

    Every appliance has a label, with numbers, adjacent to where the power cord connects. You do need to understand those simple numbers. The standard wall receptacle is 15 amps. That means an appliance cannot consume more than 13 amps. A UPS will either list its maximum amperage consumption (probably single digit amps) or wattage (probably hundreds of watts). That means a UPS consumes only a fraction of power possible from that receptacle and breaker box circuit breaker. Each circuit breaker will also state its amperage rating (15 or 20).

    Those consumption numbers (amps or watts) must also be only a fraction of the rating for that power cord or power strip (with 15 amp fuse).

    Unfortunately, you must know these basics about electricity. Since eventually you will become the responsible party required to know this stuff and its consequences. You are doing what we all did to learn these basics.
  14. Brian33 macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    I think we're getting overly complicated here. CatAndTie, your rental place is either properly wired with proper breakers/fuses, or it's not. If it's not, plugging in any electrical device could conceivably increase the risk of electrical fire (by overloading the circuit). It's the responsibility of the homeowner and the installing electrician to make sure it's safe. Should you trust them? I don't know!

    However, most likely the circuits are properly protected from overload by appropriate breakers or fuses. If that's so, then the worse thing that could happen when you plug in your computer, UPS, drives, printer, and extension cord in your office would be the tripping of the breaker or "blowing" of the fuse protecting that circuit, indicating too much current draw (too many working devices) on that particular circuit. It's not likely, but if it happens, unplug the computer stuff and reset the breaker (or replace the fuse) and come back here for advice about getting some load off that particular electrical circuit or using a different one.

    There is an issue with long extension cords and drawing a lot of power through them: ones with thin wires can get warm or even hot. Ones with thick enough wires will not because they have less resistance to the current flow than the thin ones (resistance produces heat).

    My advice is to use a power strip temporarily to plug your computer and stuff into the existing receptacle and see if it works. If it does, buy an extension cord the length you need and with the thickest wires you can reasonably find (more about that below). If it worked w/o the extension, I think the odds are very high it will work fine with a (quality) extension cord. If instead, it blows the fuse, replace it and think about alternatives then.

    I'm NOT a qualified electrician, but I've run a few new 120- and 240-volt circuits in my home, and I read (and understood) the relevant sections of the electrical code handbook. BUT, that was 10 or 25 years ago and I've never known everything a real electrician would.

    More about wire thickness: for now I'm going to make the assumption you're in the US or can make the appropriate translation.

    Wire "thickness" is called "gauge", at least here in the US. And just to make it confusing (ha ha) the lower the gauge number, the thicker the wire (and the less resistance to current). I think I'm right that most household electrical circuits are wired with cable that contains 14 gauge wires. Ads or specs may say AWG14 for American Wire Gauge. Also, a cable (that contains several wires) might have a spec of 14/3 which means 3 conductors of 14 AWG.

    There, now you can go out and buy the best current-handling extension cord available. You might want this one (amazon. For US$16, it's AWG14, and all the others I saw were AWG16, AWG18, or unspecified (surely thin gauge wire).

    There IS a way to calculate the effect of an extension cord on a household circuit, but I admit I don't know or understand it. My opinion is that it's not going to have a significant or noticable effect on your (future) UPS or computer. I can't see how using an ext. cord could damage your UPS or computer, but maybe someone will correct me...
  15. CatAndTie thread starter macrumors newbie

    Sep 9, 2011
    Thanks! This all makes the most sense to me in this particular situation. I do believe we were getting a bit over complicated for this situation. I've been running 2 externals, my computer, and a printer, and some phones charging on a basic surge protector now for about a month with no issues of tripping breakers or blowing fuses, so I'm assuming here that this particular outlet can handle it.

    This landlord seems to get most things done the proper way, so I'm fairly confident that a licensed electrician did the work setting up the circuit breaker boxes downstairs as well. I can see if I can convince him to get somebody in here to install another outlet and maybe check out our breaker boxes while he's here to make sure everything is good to go, but we'll see what he says!

    So, I definitely am leaning towards getting a nice sized extension cord and running it along the wall, then plugging a UPS into that closer to my computer. Anyone have suggestions on what kind/type of UPS to purchase?
  16. skinny*k macrumors regular

    Feb 21, 2011
    CatAndTie, I didn’t mean to sound alarmist, its just that your mention of an “old farm house” and only “one outlet” in the room raised a flag for me.

    I do have a concern about that fuse-box—the one with the 60 Amp fuses; if it does go to the neighbor’s house, it does not meet code, and it did not meet code when the circuit-breaker panel was put in, unless the electrical upgrade was done before the house was divided. By code, the resident must have unrestricted access. I only mention this because it suggests the possibility that the upgrade was jury-rigged, and that there may be other problems.

    At this point, I think that Brian33’s advice to proceed is reasonable, provided that you check to make sure that the office outlet is protected by a circuit-breaker, and not a 60 Amp fuse. You might also check to see what other outlets are protected by the same breaker; you won’t want to share the breaker with the refrigerator or other major appliances.

    As far as the Amp rating of the box, there should be a label—either on the face of the box or on the inside of the door, if it has one—stating the Amp rating, but they are often missing or painted-over. The box’s rating isn’t as important as how many circuits are there, and how well everything was done; a 10000 Amp service won’t protect anything if its only protecting the two circuits of the original house wiring; not counting any breakers that have two switches pinned together (those are 220 vac breakers, and you should have one for any 220 outlets you may have, like an electric stove and/or clothes dryer, and one for the MAIN breaker, but the MAIN breaker may be outside by your meter) again, not counting the 220 breakers, how many breakers are there? More is better.

    How about a picture of both boxes, with the doors open, if they have them?

    And, oh yes; it may be that those two 60 Amp fuses are your MAIN fuses, and I’d feel a lot better if that’s the case.

    I like APC UPSs, and I recommend getting one with a “true sine-wave” output, and not their cheaper options; they don’t cost that much more in a given power range, but the synthesized sine-wave UPSs can cause problems, and sometimes damage equipment—how often do you have power failures or brown-outs? Just wondering...
  17. Brian33 macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    OK, I'll give it a try. The basic idea is that you want to add up the watts consumed by each device on battery power and come up with a total. From that total find various brand UPSs that can just barely handle that load for a few minutes (long enough to shutdown everything cleanly) and then look "up" the model lineup and buy the UPS that can handle that load and costs a "reasonable" amount. Buying the higher-rated UPS will give you more minutes of operation under battery power (and/or the option of adding more devices later).

    The critical UPS spec is given in VA and (usually) also in watts. The higher the number of VA or watts, the longer the UPS's battery will be able to power your equipment, and the higher the cost of the UPS. I have a fair understanding of DC volts, amps, and so on, but I admit that at this time I don't understand the technical workings of VA. So, I go mostly by watts (energy per unit time).

    UPSs have two types of outlets. Some are surge-protected only, and some are surge-protected and powered by the battery in the event of a power loss. Call them "surge-only" and "battery".

    First, decide which of your devices will be plugged into which type of outlet. Devices that may "cause a problem" if power is suddenly removed should be plugged into the "battery" outlets. (E.g., the computer and probably all external disk drives.) Devices that can handle and don't really matter during a power outage get plugged into the "surge-only" outlets. (E.g., your inkjet printer, probably any optical drives, USB hubs not used for hard drives, etc.) Network equip. is a little bit of a grey area -- if you have the battery capacity, it's nice to be able to use the network/internet for a last few minutes before shutown, but that's just a luxury. So network devices like switches, modems, routers can go on either "type" of outlet depending upon the capacity (and cost) of your UPS.

    So, add up the watts used by all of the devices to be plugged into "battery" outlets. I don't know which mid-2011 iMac you have... here is the power consumption of mid-2011 iMacs according to Apple. Pick the "CPU Max" power consumption. So I'll assume you have the highest... 200w at max.

    Now you should add to 200w (for example), the watts from each external disk. Here's where you might run into a problem -- I checked my external drives and didn't immediately see any power consumption info. You could probably get it by searching, or at least get an "average" value. The good news is that the external drives will use much much less that the iMac. I would guess 20w each (unless they're bus powered--then they don't count).

    You can see this takes some estimating, but that's OK, just want to get in the ballpark. Now go and check what each UPS your intereested in can do with a (for example) 300-watt load. APC has a handy page that will give you the run-time (on battery) for various loads, so check it out: apc Back-UPS Pro. Also cheaper line: apc Back-UPS.

    Say you want a run-time of 14 minutes. Now from the above you know you want a UPS with a VA of 1000. (From the product name and specs of the BR1000G model, and we also see it's rated at 600 watts.) We also see it's rather pricey, so you may want to reduce your run-time requirement and/or check out other brands. Look at other brands of UPS (like CyberPower) and look for a 1000 VA/600w (or whatever) model and compare prices.

    CyberPower gives this handy page showing run-time at half-load (half of their wattage rating): CyberPower AVR.

    Well, hope that helps some, anyway.
  18. Chippy99 macrumors 6502a

    Apr 28, 2012
    I think you Americans with your 110v supplies have a whole load more to worry about than here in Europe where the current required is only half what you guys need.

    I have only 1 accessibly power outlet at the wall. Off it, I run a 10 extension block, with other extension blocks running off that one. Off these, I have a colour laser printer, an inkjet printer, a fujitsu scanner, a THX sound system, modem, wireless router, a PC with 700w internal power supply, a wireless phone base station/answering machine, a couple of Apple USB chargers and a 750w UPS with Mac Mini and 27" Eizo monitor attached!

    It is all absolutely allowable, within spec and works perfectly.
  19. Brian33 macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    Wow! Might heat the place, too! Just kidding -- you're probably right about the 110v.

    Also, just wanted to add for the OP, I've been using a CyberPower CP685AVR-G "AVR" UPS for five(!) years with no problems. I've had numerous short and long power outages and it's worked wonderfully. It's probably a bit undersized, as my 2008 iMac draws 280w, plus I've got two external drives and a network switch on it. Original battery, but I wonder how long it would power this load now...

    Oh yeah, be prepared for periodic battery replacement (or UPS replacement) every few(?) years...
  20. westom macrumors regular

    Nov 8, 2009
    Discussion such as wire gauge made things complex. If discussing wire gauge, then you must also discuss parameter for insulation, plug strain release, cord length, and a long list of other parameters. Simplify it for 'guys'z: it must be UL listed. Then the maybe 20 other concerns are eliminated - including wire gauge, insulation quality, and cord length.

    Of course, if you daisy chain extension cords, then you have compromised that UL listing.

    With a 'guys' knowledge, then identifying a breaker box problem is often only observation. If an electrician will visit, then have him show you what to look for. Especially what is the number for that main fuse/breaker. And identify key numbers on each breaker.

    Selecting a UPS: again, numbers on the label of each appliance are necessary. No way around an amp, watt, or VA number. Sum current (or wattage) of everything attached to a UPS. And then learn something more.

    A UPS battery will degrade quickly - in about 3 years. Due to battery degradation (and other factors you need not know), then a load of maybe 350 watts (ie almost 3 amps) requires a UPS of about 500 watts. Only then will the UPS provide temporary and 'dirty' power even three years later.

    BTW, all UPS (in battery backup mode) output simulated sine waves. This 120 volt 'pure sine wave' UPS is 200 volt square waves with a spike of up to 270 volts. That is ideal power for most electronics. And potentially harmful to motorized appliances. A UPS is temporary and 'dirty' power for during a blackout. Does nothing to solve problems created by a receptacle on the other side of the room. Does nothing useful for low voltages or rumored power conditioning.

    Described were things that 'guys' must learn. For example: what each (main and individual circuit) breaker does by simply looking inside that box. Whether a fuse is properly sized. What is necessary for any power cord and why you need one particular type (three wire type). What a UPS solves/addresses. And what should not be powered by a UPS.

    And finally, a computer with a 700 watt supply is not consuming anywhere near that power - despite popular myths. Otherwise it would be outputting heat like a toaster. If designed by an engineer, that computer would have a maybe 250 or 350 watt supply for a load that is even much smaller. Too many computer assemblers install 700 watt supplies due to hearsay, urban myths, and minimal personal knowledge of electricity. Should you doubt these numbers, then view what so many learned by actually measuring (with a layman's tool):

    Bottom line: everything in this and previous post are stuff that any 'guy' knows or should be learning. For example, a wire gauge number is nice additional information. But more important for an extension cord is a UL listing. UL demands many other important facts that most 'guys' do not and need not learn.

    One more point. Skinny*k's concerns were quite justified. Again, the household 'guy' is responsible for identifying and averting problems (such as a house fire) by knowing some simple basics. And by knowing what to look for. Skinny*k's requests for information (ie pictures) would be cational for the 'guy' who will eventually must be the informed homeowner or parent.
  21. Nuke61, May 31, 2013
    Last edited: Jun 1, 2013

    Nuke61 macrumors 6502

    Jan 18, 2013
    Columbia, SC
    Your plan will work perfectly fine; just make sure you get a new extension cord appropriate for the distance you want to cover. A U.L. approved cord will be correctly sized. As far as the UPS goes, I have two CyberPower UPS's and they both work well. They are

    HOWEVER... two things to note: 1) the simulated/modified sine wave UPS caused my iMC to make a buzzing sound when on battery power, and 2) they are oversized because I wanted to be able to use the my computer for a while during a loss of power. We recently had a power outage and I used my computer, router, and NAS support for about 20 minutes and was only down to around 50%.

    Macs, and probably most newer computers use Power Factor Corrected (PFC) power supplies that perform some input power modification. Some simulated/modified work O.K. with these PFC computer power supplies, but there are others that simply do NOT work with PFC power supplies.
  22. Nuke61, May 31, 2013
    Last edited: Jun 1, 2013

    Nuke61 macrumors 6502

    Jan 18, 2013
    Columbia, SC
    Incorrect, stepped sine wave UPS put out square waves, but true sine wave UPS's put out sine waves. While they can be dirty, any quality sine wave UPS puts out a sine wave comparable to normal home AC at the wall.

    You're also wrong about them doing nothing about low voltages or "rumored power conditioning" because an UPS with power conditioning has the ability to boost/buck line voltage using an AVR circuit *prior* to battery backup kicking in.
  23. Chippy99 macrumors 6502a

    Apr 28, 2012
    Yes, but at least you don't kill yourselves when messing with electrics and it does wrong... unlike over here where it happens all the time :-(

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