I have a 2200va UPS that I want to feed a branch circuit with, it is currently on a dedicated circuit which I want to pull out of the panel and put a cord and plug connected UPS in-line with. The UPS has 4 NEMA5-15 on the back of it now with no hardwire connections. I would install a 15 amp recpticle at the panel for the feed. What would be the best way to go about connecting the NM-B to the 5-15? I thought about a small spa panel, wire some SJ with a cord cap to the feed, install a 15 amp OCPD and wire my load to the OCPD. I know it will work but is this a code complient installation? The UPS will feed some outlets and a couple ceiling lights. Does anybody have any other ideas? Thanks

Jim

[This message has been edited by JCooper (edited 09-27-2004).]

I am not sure there is a code compliant way to use a cord and plug connected UPS to feed premise wiring.

I suggest the UPS is put at the point of use.

Anyone else got some ideas?

I also vote with putting the UPS at the point of use Tough to do for those light fixtures), or buying one that is meant to be hardwired.

If you do what you propose, you will be installing flexible cord as part of a branch circuit, this is definitely not allowed.

Tom

[This message has been edited by Tom (edited 09-27-2004).]

I knew that flexible cord wasn't allowed for a branch circuit, I was just curious if there was some kind of a loophole, like a feed from a generator. I got the ups free from a tearout that I was on so I don't think I will be purchasing a hardwire model, do they make any that small? I thought only the much larger output ones came with the hardwire option. I can hardwire the input, but the output would still be cord and plug. THanks

Jim

There is really no loophole for a generator.

If the generator was permanently installed as this UPS would be rubber cord would not really be an option either.

Code wise you can not put a cord cap on NM. (The UL white book makes this clear.)

And you can not use rubber cord for branch circuits.

Sorry I do not have an answer for you.

406-6(B) would prohibit you from using a double male ended cord.

You can make this code compliant as long as you can isolate the circuit via some kind of transfer switch, like you would for a portable generator. Basically you can backfeed the circuit if you isolate it, however getting around the way the unit yo have feeds may be a problem.

I figured that there would be no way around the cord and plug connection, I just wanted to see if there was something I was overlooking, and I wouldn't even consider putting a cord cap on NM. Thanks for the replies

Jim

One problem I have not seen addressed yet is UL listing. As long as the unit is plug and cord connected, NEC does not have anything to say about it. But once you cross over into making it part of the wiring system, NEC does pertain. And in this case the UPS becomes a SDS, for which is not made or listed for. You would have to purchase a UPS made and listed for the purpose.

What about using a panel mount receptacle and a panel mount inlet to plug the UPS into? These could be mounted into a 12x12x4 screw cover box then the only cord involved would be the one permanently attached to the UPS and all of the NM would still be in listed enclosures. Shoot it down...

400.7(A)(8) would seem to permit both the supply to and the feed from the UPS to be a flexible cord. Clearly this UPS is intended to be used with flexible cords on both the input and the output

I do not see the use of a flexible cord in this situation as a problem, as long as all of the standard flex cord precautions are met. There are UL listed generator transfer switches that use a panel mount twist-lock inlet, and which are connected to the generator via a flexible cord.

The SDS issue is also a red herring, because most UPS devices are not galvanically isolated input to output, and are thus more like auto-transformers. Both ground and neutral continuity are maintained through the devices, and thus they are not SDSs.

-Jon

I don't believe that a UPS is an appliance, other than built in losses, it does not consume power and it certainly doesn't wash my clothes or fry my food .

Flexible cord is not a Chapter 3 wiring method and cannot be inserted into a branch circuit. Check out definitions of "branch circuit " and "appliance."

Tom

UPS installation can be complicated. To start with, the UPS is only PART of the system; just as inportant is the transfer switch.

OK, so your UPS needs to be addad to the circuit. Yours sounds small enough to easily fit into a pull box, and be hard-wired.
Larger units, which often have wheels, are commonly attached with SO cord. These cords are connected to the panel with strain-relief connectors, and hard-wired to the circuit.
For other applications -such as a means to attach a power cord to a trailer, the device used is called a "power inlet." It's kind of like a cover plate with a plug mounted in a recessed area. This allows you to push a cord cap onto it. The problem with a UPS is that these prongs will be 'hot' as long as the batteries have a charge.

The first thing to do is contact the UPS manufacturer, and find out what his reccomendations are.