Small centralized UPS

[RickH]

I need to put a centralized UPS in my business office. Do I need to get into an expensive 3 phase unit? Or will the elecrical code allow me to distribute the outlets from a less expensive 115v consumer UPS, through existing conduit, (to orange outlets), to 3 separate offices? The number of computers I need to protect can easily be handled by a larger consumer unit. However my question is on the code legality of distributing the UPS outlets back out to the 3 offices. I can esily pull dedicated wires through the conduit. I would keep the UPS unit in the electrical room by the mains.

[Ed Pawlowski]

There are probably ways to do it, but it may be cheaper to buy separate UPS units. Even a $100 unit can save the day.

[trader4]

It would seem to me that "less expensive consumer unit" and wiring an appropriate size unit for 3 offices are mutually exclusive. Why not just use a seperate consumer UPS in each office ? Aside from the cost, the consumer units come with outlets built-in. How are you going to then wire that in for distribution?

Another note, whatever you get, you surely don't need 3 phase, unless you have 3 phase eqpt in those offices.

[George]

You certainly don't need a three phase unit (or even a large single phase unit)to have a unit that can be directly wired into your electrical system.

[JIMMIE]

Installing these to code is going to be expensive, much more than just putting a consumer grade UPS at each place it is needed.

Jimmie

[RickH]

.

I meant 3 phase on the primary side of the UPS unit where the output of the unit is a single phase inverter to 115v.

For hookup I was thinking of making extension cords out of 3/8 BX cable and steel plugs. Those would go to a pull box. From the pull box I would go into the subpanel just to pass-thru into the conduits. UPS would be secured to the wall.

It is a commercial office condo unit with 3 phase main, but I have a single phase subpanel for these offices (signage, parking lot, AC, heat, etc is common and 3 phase). All the conduit from the subpanel is 3/4 so there is plenty of room. I just dont know if it's ok to distribute from a plug-type UPS unit, or if I have to look for a wire- in unit (which I've had a hard time finding).

[EXT]

Code varies from location to location, so no one can answer your question accurately. However, most codes do not allow different electrical systems in the same conduit and electrical boxes. A UPS in most locations would count as a separate electric system as it would be powered when the mains are cut off and could present a problem if someone worked on the conduit after turning the mains off or interconnected the two power systems. I think you would have to install a separate conduit or wiremold raceway to carry UPS powered lines.

[RickH]

Thanks,

I'm so used to pulling, I didn't even think of wiremold, that I know would be up to code. I can easily come down into each office from the drop ceiling and still keep the plug-type UPS unit(s) locked up in the electrical closet.

[George]

Direct connect UL approved for purpose units are commonly available but not in big box. You get them where you get any other commercial quality stuff.

[RickH]

...

Yes, but I'd still have the issue of combining the electrical systems unless I use a dedicated raceway. I think just getting a larger APC or Triplite consumer unit and distributing with wiremold is the best fit for this cost-wise. About 5000VA is all I need mostly to keep the network LAN and servers up for a half hour or so, the desktops are shut off at night. The unit I'm looking at has a built in web server to check on its status remotely too. I'm not building a whole data center but like the idea of being able to lock up the UPS centrally. All the small data-center wire in units I've seen start above $5,000.

[LouB]

But you did not respond to the idea of just using individual consuner UPS systems. WHy not go that route?

Lou

[Bill]

sounds like he wants to reinvent the wheel

[dpb]

RickH wrote: ...

...

You'll still need the conduit above the ceiling for commercial I think for Code w/ the wiremold on exposed walls.

If it were me, I'd probably solve the connection problem by removing the UPS plug and making that a permanent junction box instead if going that route.

But, depending on the arrangement and number, I'd agree it seems the individual units might still be simpler/cheaper depending on just how many there are that really need the UPS.

--

[John Gilmer]

The cheap units have cheap batteries (and a cheap battery charger) and the result may be that when the "mains" go down, that may not carry the load long enough even to safely shut down the system.

There are "code" provisions for "separately derived" power sources. It's no big deal. The grounding and "bonding" rules still apply.

Three phase equipment is a good idea at higher power levels. If you are talking of a "pure" UPS (rather than a system that does a quick transfer from mains to inverter, a 3 phase input will reduce the cost and increase the efficiency. On the output side, a reasonably balanced 3 phase system can provide better results at the same cost.

If you really, really want to have secure data, you want a good and well thought out UPS.

Note that "they" make PC power supplies that take in 48 volts DC. These can be powered directly from a battery. For most data handlling a server applications this might be the most cost effective approach. You still would need a "traditional" UPS for the monitors but your "power glitches" of a few second or even hours would not cause any data loss.

[RickH]

I first thought of buying 4 separate UPS units and lock up the one for the LAN but decided against that, costs more.

I secure the servers and LAN equipment in a separate room, so since a UPS is becoming an integral part of the network now, I want to secure that too. The desktop computers are less important to have on the UPS because no critical data is on them and shut down at night, but I would still like UPS outlets available to the 3 office cubes. I simply dont want the LAN or server hardware accessible to anyone but me, same with the UPS its plugged into. The servers are up 24/7, except when the new UPS does a controlled shutdown of the servers in the event of a power outage.

[mkirsch1]

That's not taking into account wiring per code. If you could get away with snaking extension cords through existing conduits (you can't), then it would probably be cheaper to go with a single central unit.

[chrish57]

[RickH]

p <

The desktops are already networked into the LAN, the servers and network stuff is already locked up separately without a UPS. My intention was to put a UPS with the secured servers, then install orange outlets in 3 cubes for the desktops all hooked to the one locked up UPS. I dont understand what you&#39;re suggesting. I&#39;m just trying to avoid having UPS hardware in the cubes if my locked up UPS already has 3000 to 5000VA available and is secured.

[Wayne Whitney]

To do this in an NEC compliant way, you&#39;d need to install permanent wiring between the server room and the cubes using a wiring method appropriate for your building type. You can terminate the server room end of each run with an inlet that will accept the female end of a cord. Then you can use a short cord to connect the UPS outlets to the inlets.

There may be labeling requirements for the receptacles in the cubes to indicate that they are powered by a source (the UPS) that will not be shut down by the main breaker, I&#39;m not sure about that. Another possible issue is that these UPS powered repectacles couldn&#39;t be disconnected without access to the UPS, which you indicated would be kept locked. I don&#39;t know if that would be a problem.

Cheers, Wayne

[Van Chocstraw]

Get your self an auto start back up generator, then you can keep working when the power goes out. Then you only need an el-cheapo UPS on each computer to hold them while the genny starts up.