Safest way to put a UPS inline with a circuit?

Red Squirrel · 12-06-2010, 10:08 PM

I will be installing some sockets and I want them to be UPS protected, with the UPS out of that room. I can put a plug end on the romex feeder and plug into a UPS that is then plugged into a socket that then goes to the panel but from my understanding this is bad practice, I'm guessing because of how rigid the wire is, and the plug end is designed more for stranded wire.

What if I get some heavy duty extension cord wire (12 awg) for the plug end, and have it go to a junction box that converts back to romex? Or is there a better way? I'm sure they make inline UPSes but I'm hoping to be able to use a standard one.

This is for a custom PDU I will be making for my server room. Basically a serries of receptacles on a wood strip using proper wiring boxes, covers etc... and wire not exposed. The PDU would technically be a separate entity so not even sure if code comes into play here, but I want to play it safe. It will be maybe even be attached to the structure (from ceiling to floor, on both sides of the rack), so technically it probably will count as being part of the house, and be no different then a wall with plugs on it.

joed · 12-06-2010, 10:55 PM

No You can't put a plug on romex. But you can install an inlet and make cord to plug from the UPS to the inlet.
Here is an example of an inlet. They make them to fit electrical boxes also.

Red Squirrel · 12-06-2010, 11:02 PM

Hmm that seems like a good idea. I'm guessing this inlet installs just like a normal receptacle?

From there I could buy or make the proper extension cord to go to it.

homerb · 12-07-2010, 12:55 PM

I've thought about this as well to be able to keep my wall mounted TV running if the power goes out, or to keep everything in the home office room running (including the lighting fixtures) running.

What kind of UPS's will you be using? Rack Mount? Expandable? What size?

I was thinking of buying a used 1500W to 3000W rack mount APC UPS on Craigslist. One with dead batteries, so it'd be cheap. I'd then hook up a bank of cheap 12V car batteries to dramatically increase the capacity and runtime.

While the smaller UPS's don't really have the circuitry to charge a larger bank of batteries, or to run for a longer period of time than they were designed for, but the professional rack mount ones have cooling fans, better charging circuits, and are designed to be expandable.

Interesting.

Post up some pics!

Red Squirrel · 12-07-2010, 01:04 PM

I only have a 1000va Ultra unit now, but eventually I do want to upgrade to a 3000va UPS. I recently ordered a rack, waiting for it to be shipped now. I'll have to bolt it to the ground.

I've also thought about using car or marine batteries, they're much cheaper, and higher capacity.

homerb · 12-07-2010, 01:09 PM

Quote:

Originally Posted by Red Squirrel

I only have a 1000va Ultra unit now, but eventually I do want to upgrade to a 3000va UPS. I recently ordered a rack, waiting for it to be shipped now. I'll have to bolt it to the ground.

I've also thought about using car or marine batteries, they're much cheaper, and higher capacity.

You can wire them into big banks in series, parallel, or series parallel depending on the voltage of the UPS, either 12V, 24V, or 48V.

If you can find a bunch of generic car batteries for under $50 each from Sams Club or something, you could get 4-8 batteries and keep your room running for at least an entire day.

joed · 12-07-2010, 06:27 PM

A 15 amp circuit is only 1800 watts. No point in getting a bigger one unless it has two separate outputs and you are installing two separate circuits.
If you want to go bigger you need a sub panel with separate breakers. Then feed the panel from the UPS.

Red Squirrel · 12-07-2010, 06:47 PM

I think they have built in breakers for multiple 15 amp circuits, but definitely something to look at before buying.

RTypeEman · 12-08-2010, 08:33 AM

ive been working on a similar project in my home.

two bedrooms, two ups outlets in each bedroom, wired with 14/3. outlets were wired as if they were going to be MWBC split outlets. looking at using one of these per bedroom (http://www.grainger.com/Grainger/HUB...ck-Inlet-3D650) to connect to a custom built extension cord that will plug into both surge and battery sides of the ups. after doing testing on my ups units, ive determined the neutrals (battery and surge) inside them are tied together, even when running on battery. using the split circuits i am able to have surge protected and battery outlets in each bedroom.

this is how it ended up looking in each room: (red being the protected outlet)

homerb · 12-08-2010, 08:41 AM

That's a pretty nice setup! I take it, the red is for emergency power? Do you have anything plugged into them normally? Otherwise, when the power goes out, you'll have to unplug everything and plug it into the red sockets. Or, do you leave things like computers plugged into the red sockets?

Nice!

RTypeEman · 12-08-2010, 08:48 AM

well, its not finished yet, still have to sort out the area for the ups' to sit in the basement before i can finalize the hookups

LyonsElecSupply · 12-08-2010, 07:17 PM

I would recommend using the red emergency power outlets to identify the protected outlets........

Red Squirrel · 12-08-2010, 07:31 PM

Nice, that's actually how the setup is at the hospital I work at, though instead of UPS it's generator, so the stuff plugged into those will still go down, but come back up as soon as the generator kicks in.

The red outlets are very expensive last I checked though, but I will find some kind of system to identify the outlets. I think I will just number them, as I may start off with just one UPS so circuit 1 will be protected and 2 3 4 5 and 6 won't, then later on I might add another UPS and protect 2, and so on.

Also, how well do whole house surge protectors work? I'm thinking I might use one of those for that entire sub panel, that way I can skip individual surge protectors for the non UPSed circuits.

homerb · 12-08-2010, 09:27 PM

Quote:

Originally Posted by Red Squirrel

Nice, that's actually how the setup is at the hospital I work at, though instead of UPS it's generator, so the stuff plugged into those will still go down, but come back up as soon as the generator kicks in.

The red outlets are very expensive last I checked though, but I will find some kind of system to identify the outlets. I think I will just number them, as I may start off with just one UPS so circuit 1 will be protected and 2 3 4 5 and 6 won't, then later on I might add another UPS and protect 2, and so on.

Also, how well do whole house surge protectors work? I'm thinking I might use one of those for that entire sub panel, that way I can skip individual surge protectors for the non UPSed circuits.

Just spray pain them red before you install them. There you go, red outlets! Or you can put a red dot on them somewhere. Or use a label maker and write "Emergency Power" or whatever.

RTypeEman · 12-08-2010, 09:51 PM

the red outlets are actually very affordable on ebay (http://cgi.ebay.com/Leviton-RED-INDU...item35ae4b323d)