Power Bridge

[roger]

I just want to say thanks to everyone participating in this thread for keeping it so civil, this post is # 560 and there is not a single deleted post, thanks to all.

BTW, I still say it's legal.

Roger

 

[LarryFine]

I can see no code compliant use of a cord that supplies power to the fixed wiring of the building other than an Article 702 application or a Article 590 application.

What about a fastened-in-place lighting fixture, such as under-cabinet lighting, that comes with a permanently-attached length of lamp cord? We can't plug them into counter-top receptacles.

How are they to be powered? How do we interface them with building wiring?

 

[mivey]

If the INLET device instead was a 3-prong IEC type C14 male panel mounted to a wall-plate.
...
Would these devices provide a possible different application for using a power supply cord to extend circuit power from an existing receptacle outlet?

Blade configuration is not the issue.

Basis is applied as these connectors have SPECIFIC use as to power connectors for utilization equipment. These could be viewed to not be considered a substitution as they would carry specific use and be a differential of standard 5-15R type receptacles.

It is not the blade configuration. It is the fact that the appliance cord's attachment plug is required to be energized by a receptacle. FWIW, the female connection on the end of an extension cord is not a receptacle but a cord connector and the male end is the attachment plug. Installing extension cords to get around that receptacle is substituting for the fixed wiring.

 

[mivey]

Yes, extension cords are not fixed premise wiring, that is implied as an extension cord can be removed, is portable, replaceable and is not attached to the structure unless permitted in some sections of Code.

You continue to cite the word "temporary" without actual basis. It's your inserted word.

Not just me. It is common knowledge that extension cords are temporary. The places where flexible cords are allowed otherwise are specifically spelled out in the code.

Let's ask Mike:

Q. Is there a section in the Code that restricts the use of extension cords?

A. No. The NEC is an installation standard, not a product standard. However, listed extension cords should be used in accordance with the listed instructions, but this isn't a Code requirement. According to UL's Web site, extension cords aren't intended to be used as a substitute for the fixed wiring of a structure. So basically, an extension cord is only for temporary usage.

 

[LarryFine]

I just want to say thanks to everyone participating in this thread for keeping it so civil, this post is # 560 and there is not a single deleted post, thanks to all.

The night's still young.



Seriously (Hey, it could happen!), I concur!

BTW, I still say it's legal.

In case it's not obvious, I agree.

 

[mivey]

The question was addressed to Bob, but I?ll give my answer anyway. I never saw any portion of this product as constituting a portion of the premises wiring system.

The only reason I suggested it was that there was a question as to whether it provided the receptacle for the appliance. In order for it to do that, it needs an acceptable wiring method on the front end and, as you noted, the extension cord won't get it done.

OK, we agree the PowerBridge is not part of the premises wiring system. Then I can't see how it is substituting for a hard-wired receptacle directly behind the TV. It is instead an alternative, and you end up with a different thing.

If it is going to be an alternative, it must use approved wiring methods.

Under the definition of substitute you seem to be using, any utilization equipment that can be either hardwired or cord-and-plug-connected must be hard-wired. Otherwise the cord is substituting for fixed wiring.

No. The appliance cord is not in question. It only requires a receptacle for the attachment plug.

 

[mivey]

What would you call an affixed extension cord?

A violation unless it was specifically allowed.

I'm not clear which of the two receptacles in a Powerbridge installation you are referring to here. I would say that the premises wiring system ends at the first receptacle (into which the Powerbridge cord plug is inserted), and you are running some additional wiring in the wall as a way to avoid running a long power cord directly to that first receptacle. So you are not substituting cord for in-wall wiring, you are substituting in-wall wiring for part of the cord.

So call it an extension cord. Where is permanent use of an extension cord to an appliance allowed?

Let me try to rephrase my argument about powerbridge and its relationship to utilization equipment that may be either cord-and-plug-connected or hardwired.

(1) If 400.8(1) means "don't use a cord in any place where you could use a Chapter 3 method", then any utilization equipment that could be hard-wired would have to be hard-wired, you couldn't use a cord with it. (2) That seems absurd, so we reject that interpretation.

Not so fast. The utilization equipment can have its own cord and that cord may have an attachment plug. That is specifically allowed.

Using a cord (cord connector) to power the equipment cord is where the trouble starts. The code says the attachment plug shall be energized from a receptacle outlet.

 

[mivey]

I just want to say thanks to everyone participating in this thread for keeping it so civil, this post is # 560 and there is not a single deleted post, thanks to all.

BTW, I still say it's legal.

Roger

Well, there's a post that should be deleted if I ever saw one. :grin:

 

[wwhitney]

I can see no code compliant use of a cord that supplies power to the fixed wiring of the building other than an Article 702 application or a Article 590 application.

I can think of a couple, but they are pretty out there:

(1) A rotating or moving building or portion thereof. Say a small (very unusual!) house or a large telescope dome. Under 400.7(A)(9) you can use a cord to interconnect the wiring in the fixed section and in the moving section.

(2) A test house or building built on a shake table for earthquake testing. Under 400.7(A)(7) you could use a cord to provide power to the building.

Cheers, Wayne

 

[mivey]

What about a fastened-in-place lighting fixture, such as under-cabinet lighting, that comes with a permanently-attached length of lamp cord? We can't plug them into counter-top receptacles.

How are they to be powered? How do we interface them with building wiring?

With approved wiring methods. Got a particular fixture in mind?

 

[wwhitney]

What about a fastened-in-place lighting fixture, such as under-cabinet lighting, that comes with a permanently-attached length of lamp cord?

I took Don's statement to only include situations where power travels through building wiring after going through a cord.

Wayne

 

[don_resqcapt19]

What about a fastened-in-place lighting fixture, such as under-cabinet lighting, that comes with a permanently-attached length of lamp cord? We can't plug them into counter-top receptacles.

How are they to be powered? How do we interface them with building wiring?

How is a cord that is directly attached to the light fixture supplying power to the building wiring system?

 

[wwhitney]

Using a cord (cord connector) to power the equipment cord is where the trouble starts. The code says the attachment plug shall be energized from a receptacle outlet.

OK, so 400.7(B) is your reponse. So does "energized from a receptacle outlet" mean "the attachment plug must be inserted into that receptacle outlet"? If it does, then 400.7(B) bans all extension cords. That seems unlikely, so I can't accept that interpretation.

So instead, "energized from a receptacle outlet" means "power from the service passes through a receptacle outlet before reaching the attachment plug." In the typical Powerbridge installation, this requirement is met: the first receptacle (that the Powerbridge cord is plugged into) is a receptacle outlet, and the appliance attachment plug is energized from that receptacle outlet.

Cheers, Wayne

 

[mivey]

OK, so 400.7(B) is your reponse. So does "energized from a receptacle outlet" mean "the attachment plug must be inserted into that receptacle outlet"? If it does, then 400.7(B) bans all extension cords.

That's the way I see that it reads, except for portable equipment and temporary use.

That seems unlikely, so I can't accept that interpretation.

Yep. We all luvs the extension cords. Doesn't mean that the NEC does.

So instead, "energized from a receptacle outlet" means "power from the service passes through a receptacle outlet before reaching the attachment plug." In the typical Powerbridge installation, this requirement is met: the first receptacle (that the Powerbridge cord is plugged into) is a receptacle outlet, and the appliance attachment plug is energized from that receptacle outlet.

Cheers, Wayne

That doesn't sound logical. That means the receptacle must be somewhere in the solar system, or thereabouts. It makes more sense to say that if you have an attachment plug, then you need a matching receptacle to plug it into.

 

[wwhitney]

That's the way I see that it reads, except for portable equipment and temporary use.

Under your interpretation, where does 400.7(B) provide relief for portable equipment and temporary use?

In regards to portable equipment, are you saying that if my TV sits on a shelf on the wall, instead of be fixed to the wall, Powerbridge is OK?

It makes more sense to say that if you have an attachment plug, then you need a matching receptacle to plug it into.

Of course you need a matching receptacle, the Powerbridge install provides that. The question is whether you need a receptacle outlet, or if you can plug cords into other things. Can I plug a cord into a cord-and-plug connected UPS? That's not a receptacle outlet, the UPS is not part of the premises wiring system.

Cheers, Wayne

 

[LarryFine]

So call it an extension cord. Where is permanent use of an extension cord to an appliance allowed?

I have more than one extension cord in use in my house that hasn't been unplugged in over 12 years. One is attached to the house by cable clips that hold it off the floor along the baseboard.

Permanent?

 

[LarryFine]

With approved wiring methods. Got a particular fixture in mind?

I pictured 120v pucks, but there are other cases of rubber cords that directly wire-nut with building wire, such as commercial exterior building lighting.

 

[LarryFine]

I took Don's statement to only include situations where power travels through building wiring after going through a cord.

How is a cord that is directly attached to the light fixture supplying power to the building wiring system?

Ah! There's the question, then!

Is the isolated section of NM between the two old-work boxes building wiring or part of the building wiring system?

Is it any of the NEC's business at all? Or the AHJ's?

If not, what's the voltage limit we could use on it before it falls back under the auspices of the NEC?



Phooey! Dinner call. "A'hl be bahk!"

 

[LarryFine]

Mmmm! Barbecue babyback ribs and sweet-potato fries!

Wow. Didn't miss anything. Okay, where was I? Oh, yeah.

I took Don's statement to only include situations
where power travels through building wiring after going through a cord.

All right. Let's take one of those pre-packaged under-cabinet lighting sets that comes with a switched multi-receptacle controller and several lights, each with a plug. A simple plug'n'play setup. (Where the light controller plugs in is a separate discussion.)

Now, let's say I want to place one or more of the lights on top of the cabinet for ambiance lighting, and run it off the same switch/control as the ones underneath. That means a wire in the wall with a plug on one end and a receptacle on the other end.

If the wire in the wall is governed by the NEC, it should be NM (or equiv.) and each end be terminated in a box, and a device as an interface between the controller's socket underneath, and one atop for the light(s). The latter is easy: a receptacle.

Now, how do we get the power from the controller's socket to the bottom of the NM? A short cord with a plug on one end and a socket on the other, and an inlet in the lower box to accept the socket seems to fit the bill. Does the NEC govern this install?

Is that section of NM part of the premises wiring system? Is the mere fact that it's in the wall, and it, the boxes, and the devices are also approved for NEC-governed use determine that this is also premises wiring? That we're feeding it power at all?

When one places a LV lighting transformer somewhere in a house and uses NM as the in-wall portion, is that also premises wiring and NEC governed? May one use plugs and sockets for the NM-to-flexible-wiring interface, or must every connection be hard-wired?

Is it the voltage level? Does every instance of 120vac in the structure automatically fall under NEC rules? What if it's separately derived, say through a 1:1 isolation transformer, or my power filter provides equal isolation? Is the output still premises wiring?

Just to close with an argument to the extreme, would an isolated section of #4 bare copper just run in the wall but unconnected be part of the premises GEC system? What if I used it for another purpose? Does intent matter, as was mentioned earlier?

 

[mivey]

Under your interpretation, where does 400.7(B) provide relief for portable equipment and temporary use?

"400.8 Uses Not Permitted. Unless specifically permitted in 400.7..."
"400.7(A)(3) Connection of portable luminaires, portable and mobile signs, or appliances"

In regards to portable equipment, are you saying that if my TV sits on a shelf on the wall, instead of be fixed to the wall, Powerbridge is OK?

Where it sits is of no importance. We would have to define portable as the NEC does not.

Of course you need a matching receptacle, the Powerbridge install provides that. The question is whether you need a receptacle outlet, or if you can plug cords into other things. Can I plug a cord into a cord-and-plug connected UPS? That's not a receptacle outlet, the UPS is not part of the premises wiring system.

That's where the fun begins. To me, the NEC oversteps its authority when it starts telling us what to do beyond the installed wiring. But they do it anyway.