Flexible cord for UPS cart

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winslowfam

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VA
Hi...we have a client who wants to place a small (50A/208V) cart-mounted UPS in a room. They chose to put it on a cart so it can be moved a short distance either way, when needed. We want to use a flexible cord (SO or SJO) for both the line side and the load side wiring from the UPS to wall-mounted JB's. Do you think this application (portable UPS cart) qualifies under art. 400.7 for use of flexible cords? Thanks.
 
Are both the UPS and load plug-connected? (Please tell us more about the application, too.) Without knowing more, I'd mount the UPS somewhere, hard wire it's input, and extend the output to where it needs to be with SO (not SOJ).
 
zbang said:
Are both the UPS and load plug-connected? (Please tell us more about the application, too.) Without knowing more, I'd mount the UPS somewhere, hard wire it's input, and extend the output to where it needs to be with SO (not SOJ).
Click to expand...

This UPS was provided with wheels so it can be rolled into place, as needed. The line side and load side cords will be plug-connected at the wall. I agree with using SO cord...I just want to make sure the application qualifies for the use of Flexible Cords...400.7. Thanks again...
 
winslowfam said:
This UPS was provided with wheels so it can be rolled into place, as needed. The line side and load side cords will be plug-connected at the wall. I agree with using SO cord...I just want to make sure the application qualifies for the use of Flexible Cords...400.7. Thanks again...
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If the UPS has not been bought yet or can be returned, I would check with Tripp-lite.

They may have what you need and would be a listed assembly. Much easier that way, no fussing.

This is not exactly what you want, but is an example of a pretty cool UPS with cords.

https://www.tripplite.com/smartonli...switch-nema-outlets-50a-plug~SU8000RT3UN50TF/
 
winslowfam said:
The line side and load side cords will be plug-connected at the wall.
Click to expand...

I'm still not clear on things (which happens often)- How would the load connect? Remove load supply plug from a regular receptacle and insert into UPS? If there's any fixed wiring between the UPS and the load itself and that's fed by a cord/plug, I'd be looking closely at "not as a substitute for fixed wiring".

A better understanding of the application would help (me, at least).
 
zbang said:
I'm still not clear on things (which happens often)- How would the load connect? Remove load supply plug from a regular receptacle and insert into UPS? If there's any fixed wiring between the UPS and the load itself and that's fed by a cord/plug, I'd be looking closely at "not as a substitute for fixed wiring".

A better understanding of the application would help (me, at least).
Click to expand...

It could be done with a set up like for a genny.

Sub panel, transfer switch, power inlet.
 
The UPS is small, rated 50A at 208V, 3-ph. It comes with casters so it can be rolled place to place, as needed. Our idea is to feed it with a SOW cord, connected to a twist-lock receptacle mounted on the wall. The output of the UPS would be cord connected to a pin and sleeve receptacle on the wall, with the sleeve (female) being connected to the cord and the pin (male) assembly being mounted on the wall. This would prevent any energized pieces from being exposed. From the pin assembly (load) on the wall, we wire to a distribution panel in the room.

My main question is, does this installation qualify for the use of flexible cords and cables per 400.7, or other portions of the code? The UPS needs to be able to be moved a short distance, at times, while in use.
 
I don't understand why it being on the wall would be a concern. The receptacles have to be mounted somewhere. Could you clarify? Thanks.
 
The point is that if the portable UPS is connecting back into fixed wiring, that may be a problem.

Without knowing the specifics of the setup, it we have-
supply breaker ->
female wall-mounted PS ->
cord mounted PS ->
cord ->
(spliced to THHN in conduit) runs to equipment
THHN hard-wired onto equipment terminals

Just that set of pin/sleeve connectors will be a problem for some AHJs, the UPS is just icing.

On the other hand, if the output of the UPS connects to a cord-mounted P&S and that cord is the sole feed to the equipment, that is probably alright for the UPS. Still might be a violation of the "fixed-equipment" rule.
 
hbiss said:
As soon as you mount a receptacle on the wall it becomes part of the structure. You can't use portable cordage to wire a structure.

-Hal
Click to expand...

He's not using the cord to wire the structure, he's using the cord to connect the load side of the UPS to an "Inlet" mounted on the wall, which , if this inlet is wired directly to a panel which feeds a stand alone emergency panel there is not transfer switch per say.

The transfer takes place in the UPS Unit itself.

Most small UPS units I've seen like this are wired inlet and outlet with cord and plug on purpose, so that if something was to go wrong with the UPS unit itself, they can unplug the house power from the UPS and plug house power directly into the inlet feeding the panel and get things back up and running on house power only.

This is not unusual.

The only thing that doesn't add up it the "Used only when needed" part.

The whole point of a UPS is to be online and charging at all times so when the power goes out the UPS would be fully charged and make a seamless transfer.

To me, they are not wanting it for a "Roll Up" situation as much as they would want the cord and plug install if something should happen to go south with the UPS.

That's been my experience with this type of install anyway.


JAP>
 
zbang said:
The point is that if the portable UPS is connecting back into fixed wiring, that may be a problem.

Without knowing the specifics of the setup, it we have-
supply breaker ->
female wall-mounted PS ->
cord mounted PS ->
cord ->
(spliced to THHN in conduit) runs to equipment
THHN hard-wired onto equipment terminals

Just that set of pin/sleeve connectors will be a problem for some AHJs, the UPS is just icing.

On the other hand, if the output of the UPS connects to a cord-mounted P&S and that cord is the sole feed to the equipment, that is probably alright for the UPS. Still might be a violation of the "fixed-equipment" rule.
Click to expand...

More like,
Supply breaker to cord with Female Sleeve
Male Pin on input cord of UPS plugs into female Sleeve of cord from supply breaker.
Install Female Sleeve on output cord of UPS
Install Male Pin on cord feeding UPS Panel and plug into Female Sleeve of UPS output cord.
In case of UPS failure or need to remove UPS from the lineup for some reason.
Unplug cord with Male Pin on it feeding the Distribution Panel and plug into cord with Female Sleeve coming from Supply breaker.


JAP>
 
Maybe I'm not understanding this correctly with all this irrelevant 50A male/female/pin sleeve stuff.

You have a UPS with a line cord. It also is equipped with an output cord. Line cord plugs into a receptacle on the wall. You also have an "inlet" receptacle on the wall properly wired to feed a distribution panel. The output cord plugs into the inlet receptacle.

As long as there are plugs on the ends of the line and output cords now I see no problem.

-Hal
 
jap said:
Male Pin on input cord of UPS plugs into female Sleeve of cord from supply breaker.
Click to expand...

Are you planing to use 'standard' style wiring devices? It sounds like you are describing the use of single conductor pin & sleeve style, often seen with rental generators and welder cords
 
hbiss said:
Maybe I'm not understanding this correctly with all this irrelevant 50A male/female/pin sleeve stuff.

You have a UPS with a line cord. It also is equipped with an output cord. Line cord plugs into a receptacle on the wall. You also have an "inlet" receptacle on the wall properly wired to feed a distribution panel. The output cord plugs into the inlet receptacle.

As long as there are plugs on the ends of the line and output cords now I see no problem.

-Hal
Click to expand...

So, you would be saying that it meets the flexible cord requirements of 400.7(A)(6), with the plugs/receptacles required by 400.7(B)?
 
Yes. However I'm not sure about what you are calling pin and sleeve connectors and if the language of 400.7(B) would allow them. So let's talk about them.

"... each flexible cord shall be equipped with an attachment plug and shall be energized from a receptacle outlet or cord connector body."


-Hal
 
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