Running a Home-Office Through a UPS

mwagner_00 asks: "After spending lots of money and time, I now have an office in my home. My wife and I both have computers (mine is a high powered gaming rig), and I also have a workbench where I work on other people's PCs. I have a web/email server as well. I would like to protect the investment by running the room's power through a UPS. I have a APC 3000NET that my workplace was going to throw out. The only thing it needs is a good set of batteries. Has anyone tried something like this before? Basically I want to find the breaker for the room, and after the breaker, run the power through the UPS and back out to the room. Is the UPS that I have sufficient to run a whole small office?"

My recommendation

[RingDev]

A surge strip and extention cord for the work bench. If you are going to try to patch into the house wiring you're going to want a certified electritian, and depending on housing codes in your area, you may need a certificate from the building inspector.

Much easier to mount the UPS under the work bench and to run an extention cord/surge strip to the other PCs. You don't want to have anything running off the protector you don't need. Things like speakers, printers, PDA chargers, etc.

-Rick

18 amps

[MobyDisk]

The specs say 2250 watts. 2250 watts divided by 120 volts = 18.75 amps. So, in theory, you could hook this to a circuit with an 18 amp fuse or breaker.

Of course, doing this is surely a crazy violation of electrical codes. Would it be that hard just to plug the computers into the UPS? It has plenty of outlets, it really looks like that is how it was intended. Wiring it right to the electrical box might get you some geek points, but you might also become a Darwin awards nominee.

I doubt it is worth it.

Re:My humble suggestion...

[KILNA]

A UPS only outputs power to the protected connections, the only person getting shocked would be the OP if he forgot to turn off the UPS before doing electrical work in the single room he was planning on giving backup power to.

UPS

[HotNeedleOfInquiry]

First of all, don't muck with your house wiring. It would be far better to reorganize your room around the UPS than to change the wiring inside your breaker box. It's unlikely that it would be legal and if there ever was an issue concerning fires or insurance, your ass would be in a sling.

As to batteries, I have an old surplus 700 watt APC UPS that I run 4 servers and a couple of switches on. The batteries were dead when I got it and I jury-rigged 2 garden tractor batteries in series to it. It works perfectly, but your mileage may vary. The UPS manufacturers generally *do not* want you to do this, so do it at your own risk.

Code is the key here.

[Myself]

Don't even think about doing this without talking to your city's electrical inspector. She will, of course, laugh you out of her office.

The UPS is an appliance, not a fixture. It has to be separable from the building wiring by a plug. It doesn't carry the appropriate ratings and classifications for being wired-in. Use the appropriate output cords and power strips.

That being said, you might want to do some research into generator transfer switches, and the idea that some of the house's loads would be on a separate panel that gets backup power.

Re:My recommendation

[Anonymous Coward]

I would suggest that anything connected to the computer at least be run through a surge protector - so you won't have any surges finding their way into your computer through them.

But the only thing you should have running on the uninterruptable power supply itself is the computer and monitor - the essentials only. You want to be able to save documents and safely turn the machine off should the mains power fail (or have PowerChute do it). Do not make the solution more complicated than the problem.

You'll loose flexibility...

[WoTG]

Besides the electrical code violations, you'll loose flexibility in what you can power in the room. Laser printers and other very high current appliances (maybe microwaves?) will not be good for your UPS. I've seen laser printers cause UPS's reset themselves. It's not fun having workstations loose power every time someone tries to print. =)

Re:Code is the key here.

[GoRK]

You can have your privacy, but when your house burns down and takes your neighbor's homes with it and they find this... you are going to be in a world of hurt with your insurance companies and probably the police. You can do a lot of stuff in your own home that's not legal for various reasons. Regardless of whether or not the idea has merit or is valid or even could be done safely, wiring a UPS into the breaker box is most assuredly against electric code and in the event of an inspection or investigation wouldn't even come close to being a violation that is plausibly deniable.

Of course there are a whole bunch of technical reasons you can't just feed the UPS power through the breaker box easily either, but I'm assuming that most of those will be addressed in other comments egging this guy on.

Here are your main problems

[Roadkills-R-Us]

1) Many houses and apartments are not wired the way
      you think; all the outlets in one room may not be
      on the same breaker. Other rooms may have outlets
      on that breaker. Lights may or may not be on the
      outlet with that breaker. IOW, you would need to
      test thoroughly, and probably do some rewiring.
      And you still might miss something.
2) If you miswire anything and the house burns down,
      your insurance may not cover you. You'll need to
      check what the code is where you live and look into
      inspections. Getting a licensed electrician involved
      is a good idea.
3) You don't want to plug your vacuum cleaner into the
      output side of your UPS; not great for either one
      of them. Sooner or later, something like that will
      happen.
4) If you have a laser printer, startup surges can be
      huge; not a good idea to be on the UPS.

There are others, but this should be enough. I have
to go along with the people who receommended running
one (or however many) separate outlets for the UPS.
These can be current or new outlets wired to the UPS
and *clearly labeled*. Maybe use red covers or something,
with a label "Computer equipment only" or "Ask Fred
before plugging anything in here". Of course, you'd
have to change your name to Fred.... Depending on who
could possibly be plugging things in, you could even
consider switching to no normal outlets; hardwire some
power strips into a junction box, and bolt them underneath
the desks the equipment sits on. The biggest problem with
that is moving the desks.

And finally, what happens when you move? You need to make
sure this isn't too hard to reverse, or consider what
happens if you leave it. You don't want someone coming
after you with an axe or lawyer later.

Listen to me if you want to live

[unitron]

Do not touch your house wiring. The fact that you have asked the question which you have asked shows that you don't know enough to do it safely even if it were practical. Don't take this as a personal insult. Almost everybody who isn't an electrician falls into this category (not to mention some who are, allegedly, electricians).

It's almost certain that the wall sockets in the room are daisy chained with sockets in other rooms and all off of the same breaker. Same deal with the overhead lights. This makes your plan somewhat physically impractical.

If you are going to use this unit (the UPS), get the proper replacement battery or batteries. Do not even think of using automobile batteries or anything like that anywhere indoors. Do not think of using those types of batteries outdoors with a long cord running indoors to the UPS.

Get a licensed electrician to install a separate 30 amp circuit from your breaker panel to a single outlet in the room you have set aside as an office and plug the UPS into that outlet. Make sure that the UPS is working properly before going to the expense of installing the outlet.

Use the UPS to power your computer equipment (and perhaps a low wattage lamp), excepting of course any laser printers or the like.

As long as you're going to be talking to a real electrician you might inquire about the feasibility of setting up a generator and the necessary equipment to switch between it and the power company's wires. Unless you get a *very* large generator you'll need to have things set up so that the generator feeds selected circuits in the house (lights, refrigerator, wall outlets, but not the stove, the washer, the dryer, the water heater, the heat pump, etc.) while disconnecting the power company so that there's absolutely no way for the generator to feed power back into the power company's lines or for the power company to feed into the generator's output. Whether you get a generator that starts automatically and automatically disconnects the power company and connects itself, or one that has to be started and switched manually depends on how much money you can afford to throw at it.

You may want to look into swapping this unit (the UPS) for 2 or 3 lesser ones that can be plugged into your existing 15 amp outlets if you can find someone in the reverse of your situation. That way you won't need any special wiring (unless you go with the generator idea).