Connections to UPS

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bjp_ne_elec

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Is there a limit to how long a cord can be that would be run back to a UPS? Have a situation where a telephone/computer room has a single UPS. Client is moving in to larger digs, and want to lay out so phone equipment is on opposite side of utility "closet" is on opposite wall from UPS. Can a cord be run bac, and if so, is there a limit? Not even sure which section of code this might be under.

If a cord can be used, considered possibly routing it back in a trough of some type - or just laying it in some of those hooks. The ones you might normally see with phone or computer cable laid in to them.

Thanks

Brett
 
Are you talking about running so or any other type as mentioned in 400.6 (A)? 400.8 prohibits, the use of said cords except for those listed in 400.7. How was this run before? You may have to run a little conduit.:smile:
 
What he said with a bit of an explanation.

Cords that are not part of the premises wiring are not covered by the NEC, so I guess it depends on what cord you are referring to.

IMO a power cord from a piece of plug-in equipment (such as a PC) is not part of the premises wiring. It is part of the equipment, and as such is not usually covered by the NEC.

In any event, it is a bad idea to install an extension cord for such a situation. I think the longest replacement cord you can get is about ten feet long.
 
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But once it is secured to the building it then becomes premise wiring. If he is going to hang it doesn't that then become structure wiring?
 
Are you talking about changing the cord thta is on the UPC? If so this voids the listing of the unit. If your talking about using an extension cord then this is what the NEC is written for as to the installation of the receptacles @ locations where needed.
 
bjp_ne_elec

bjp_ne_elec

You can probably tip toe around the code (calling it an equipment power cord), but why would you. You are going through the trouble of moving the room, take this time to re-work the room to make it right. It is not going to be difficult to install an outlet for the UPS, do it right now, so later it does not become a problem. Client will be happier in the long run. MY 2 cents........
 
The new situation actually calls for a UPS in two locations instead of one - that's the issue. The present UPS has the power capability, the issue is how to get from the phone equipment rack to the UPS. Presently the phone equipment rack is on the same wall as the computer rack, and the UPS sits between the two. Cords are not issue in present configuration.

I'd be interested in looking in to the UPS panel scenario. Any recommendations on vendors for these style UPS's - I have never seen one.

Thanks,

Brett
 
See my comment about UPSes having less than 120vac (or 240vac if that's what the output is) nominal voltage in the "Square wave inverters are evil" thread. Although many switching power supplies will run well below even 100V, if the UPS is outputting less than 120V as it is, and you're losing voltage with an extension cord, is that really what you want to be doing? And if you're not going to lose voltage with the cord, a second UPS might be cheaper for the customer (and safer, in terms of redundancy and on-battery run-time) than all the parts and labor involved in doing something code-compliant.

Assuming the telco gear is in a rack, I'd go with a rack mounted UPS (like this), assuming you can find one with the appropriate capacity. Go buy it, mark it up, slide it in, pickup a check.
 
bjp_ne_elec

bjp_ne_elec

Yes,, I understand you dilemma now,, I have to agree with tallgirl on this. You do not want to make the UPS work the distance, even if it is a small (relative) distance. Purchase a cheap second one it is a good solid solution...

ed
 
edamico11 said:
Purchase a cheap second [UPS] one it is a good solid solution...
Click to expand...

Arrgh!!! No, a "cheap" UPS is never a good solution, purchase a good UPS. It's not there so you can tick a box on your job sheet, it's there to protect your customer's business.

In passing, if the equipment being supplied uses a switched mode power supply, and the line voltage is a bit low, the SMPS won't mind, it will just draw more current to deliver the required power as drawn by it's load. Of course, ohms law continues to apply on the supply circuit, current is up, so the volt drop increases. Ultimately this limits how low the voltage can go, before collapse or overcurrent sets in.

Also, SMPSs really dont care about input waveform, even thouse from the aforementioned "evil" square wave inverters. After all, whats the first thing a SMPS does with input power: it rectifies it to DC...
 
dbuckley said:
Arrgh!!! No, a "cheap" UPS is never a good solution, purchase a good UPS. It's not there so you can tick a box on your job sheet, it's there to protect your customer's business.
Click to expand...

Agreed, which is why I pointed Brett at the APC 2U rack mounted UPS I did. He didn't provide a load and required runtime target, but APC has web pages he could access to find something that would provide the required runtime and likely cost less than the parts and labor to bring power over from the other UPS.
 
if the user wants regulated voltage from the UPS, having a long extension cord might be just what the user doesn't need. The drop in voltage might negate whatever voltage regulation benefits the UPS provide
 
How about this:

1. Cord (with 3 prong male plug) to wall plate (behind UPS)
2. Conduit from this JB/wall plate run to where the telephone rack is.
3. Set JB with receptacle that telephone rack equipment will plut in to.

The biggest question here is the short piece of cord.

Anybody going to shoot it down with a NEC reference. It would definitely be neatly done, as far as looks go.

Thanks,

Brett
 
I would argue 400.7 (B) '...shall be energixed from a receptacle outlet' if you are proposing to 'supply' power with the 3 prong male.

Edit: And if you are proposing installing a cord cap assembly to the wall jb, I would argue 400.8 (1) and (7)
 
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dbuckley

dbuckley

"cheap",, my God I still see the stones coming ouch:smile: .

To clarify,, I did not mean cheap as in Comp USA brand. I meant you can get a good UPS (APC for example) especially for the telco, at a reasonable price. I am sorry for the confusion, sometimes I forget my audience. I appreciate the comments however..


bjp_ne_elec,

I like your plan, and lets put the voltage drop on the shelf for a moment. But wanderer20001us would be correct if the 3prong male is energized. Would it be?
 
John Deere Man said:
Are you talking about changing the cord that is on the UPC? If so this voids the listing of the unit. If your talking about using an extension cord then this is what the NEC is written for as to the installation of the receptacles @ locations where needed.
Click to expand...

Changing the cord does not void anything. That is a myth. For practical purposes, it does not affect the warranty either. Also a myth.

An extension cord is a bad idea for several reasons. The NEC does not care about extension cords at all, because they are clearly not a part of the premises wiring. Fire codes and OSHA do care if you permanently install a piece of equipment using an extension cord.
 
muskiedog said:
But once it is secured to the building it then becomes premise wiring. If he is going to hang it doesn't that then become structure wiring?
Click to expand...

Horse hockey. There is no NEC requirement requiring a power cord for a piece of equipment be not secured. There are all kinds of UL listed devices for doing just that. UL would not list a product the use of which violated the NEC.
 
edamico11 - not sure what you're getting at - but the male would be energized. as it's plugged in to the UPS receptacle. I think you're wondering if the male plug is energized if the other end was plugged in - not the case as the male end is being fed.

Make sense?

Thanks,

Brett
 
Alright, now I'm confused.

Brett, you say that you're going to somehow plug the UPS into a receptacle located on the wall opposite the telco rack, then presumably plug the telco rack into a receptacle in the same closet with the telco rack, with that receptacle being fed through the wall -- again, my assumption -- from the other side.

This is what I get for the connections -- female receptacle on the UPS, male plug on the wire which runs into the conduit, male plug on the wire which emerges from the conduit, female on the wall outside the telco closet, wire connecting outside the closet receptacle to inside the closet receptacle, female on the wall inside the telco closet, male on cord from the telco rack to the outlet inside the telco closet. That's what I get.

I think what edamico11 was getting at is that if you do that, when you plug the male end of the "whatever goes into the conduit" (and of course, "conduit" could be whatever it is you have in mind for protecting this length of wire), the male end on the other end of "whatever goes into the conduit" becomes energized. If the far end plug isn't plugged in, the blades are hot and exposed to finger poking. That's what I think some of us are concerned about.
 
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