2017 Power Supply Cords

[George Stolz]

In 2017, an Informational Note is added to 400.1:

400.1 Scope. This article covers general requirements, appli‐ cations, and construction specifications for flexible cords and flexible cables.

Informational Note: UL 817, Cord Sets and Power-Supply Cords, allows the use of flexible cords manufactured in accordance with UL 62, Flexible Cords and Cables. See 400.10 and 400.12 for flexible cords that are part of a listed cord set or power-supply cord.

When you look down to 400.12, it reads

400.12 Uses Not Permitted. Unless specifically permitted in 400.10, flexible cables, flexible cord sets, and power supply cords shall not be used for the following:

(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar open‐ ings (4) Where attached to building surfaces

Exception to (4): Flexible cord and flexible cable shall be permitted to be attached to building surfaces in accordance with 368.56(B) .

(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings

Exception to (5): Flexible cord and flexible cable shall be permitted if contained within an enclosure for use in Other Spaces Used for Environmental Air as permitted by 300.22(C)(3).

So can I still plug in a router above ceiling and throw it on top of a ceiling tile if it is not a cord type given in Article 400?

 

[Dennis Alwon]

George I don't see where you are going with this. As I read the exception the cords can be used as long as they are in an enclosure suitable for use in ceiling used for plenums.

IMO, you cannot do as you stated but I may be missing something

 

[don_resqcapt19]

I don't see how there can be a rule in 400.12 that covers something that is outside the scope of the article.

 

[al hildenbrand]

In 2017, an Informational Note is added to 400.1:

When you look down to 400.12, it reads

So can I still plug in a router above ceiling and throw it on top of a ceiling tile if it is not a cord type given in Article 400?

George I don't see where you are going with this. As I read the exception the cords can be used as long as they are in an enclosure suitable for use in ceiling used for plenums.

IMO, you cannot do as you stated but I may be missing something

Dennis, I just reviewed the thread Cords above ceilings for the roots of George's question. The standards UL 62 and UL 817 have established that not all cords are the same, and not all cords are covered by the NEC.

George, given the quotes from the 2017 NEC that you provide, I believe the answer is "yes". But, I have to wonder if the language of the two UL standards is still unaltered?

 

[George Stolz]

At first I believed they screwed up; but after pondering it for a bit, I decided they found an elegant solution. If the power supply cord type exist in Table 400.-whatever-it-is then 400 applies to a power supply cord. If not, it doesn't.

Al, the wording in the UL standards is all but irrelevant, as Don alluded to, if it isn't forbidden by the NEC what law would prevent it?

 

[iwire]

Dennis, I just reviewed the thread Cords above ceilings for the roots of George's question. The standards UL 62 and UL 817 have established that not all cords are the same, and not all cords are covered by the NEC.

I don't see that UL has any authority at all to decide what the NEC applies to. Seems more like an AHJ call to me.

 

[wwhitney]

If the power supply cord type exist in Table 400.-whatever-it-is then 400 applies to a power supply cord. If not, it doesn't.

What about the last sentence of 400.4?

400.4 Types. Flexible cords and flexible cables shall conform to the description in Table 400.4. The use of flexible cords and flexible cables other than those listed in Table 400.4 shall require permission by the authority having jurisdiction.

I'm inclined to read the Informational Note to 2017 400.1 as an assertion that 400.10 and 400.12 apply to any flexible cords that are part of a listed cord set or power-supply cord, whether or not the flexible cord used in the list cord set or power-supply cord complies with UL 67.

Cheers, Wayne

 

[al hildenbrand]

I don't see that UL has any authority at all to decide what the NEC applies to.

Then how do we know that and bath exhaust fan installed in a tub / shower space is required to be so listed and protected by a GFCI?

Answer: It is first in the UL White Book. . . and probably in the product standard before that.

 

[al hildenbrand]

the wording in the UL standards is all but irrelevant, as Don alluded to, if it isn't forbidden by the NEC what law would prevent it?

As I allude to in my previous post #8, 110.3(B).

 

[iwire]

Then how do we know that and bath exhaust fan installed in a tub / shower space is required to be so listed and protected by a GFCI?

Answer: It is first in the UL White Book. . . and probably in the product standard before that.

It is still up to the AHJ to make the call on it.

Right in the White book it explains it is up to the AHJ to determine if a product is being used within its listing.


UL listings are not adopted, UL is just a private company. No different than 'Al H' electrical in many ways.

 

[al hildenbrand]

It is still up to the AHJ to make the call on it.

Yes. 110.2 along with the Article 100 Definition of "Approved".

So?

The inverse of an AHJ's "approval" of my installation will teach me the meaning of 110.3(B), if I am to give a working exhaust fan electrification to my customer.

 

[George Stolz]

Al / Wayne: do you throw away the power supply cord that came with your router (sitting on your desk), crack open the case and flex into it? 400.4 would require that with your interpretation.

 

[George Stolz]

Then how do we know that and bath exhaust fan installed in a tub / shower space is required to be so listed and protected by a GFCI?

Answer: It is first in the UL White Book. . . and probably in the product standard before that.

I wouldn't get that far; it's required in the instructions in the box. If not, it's not.

 

[al hildenbrand]

George, given the quotes from the 2017 NEC that you provide, I believe the answer is "yes".

do you throw away the power supply cord that came with your router (sitting on your desk), crack open the case and flex into it?

I'm inclined to agree with you, but I am curious how the language of UL 817 and UL 62 have evolved since we burrowed into it several years back. I think there might be some additional nuance that has been placed there. Just sayin'.

You will recall, from the original thread of Ryan's, and the behest of Mike, that it was the very UL language that caused the appearance that ALL cord sets and power supply cords fell outside of the scope of the NEC.

 

[al hildenbrand]

I wouldn't get that far; it's required in the instructions in the box. If not, it's not.

But how do you know that the instructions in the box even have to say that the fan is acceptable for installation over a shower / tub and be GFCI protected? The requirement for those specific parameters is not in the NEC.

By your logic, a very cheap fan that is not evaluated for installation over a shower / tub, must say that it cannot be so installed. I recently had to show the White Book requirement to a homeowner that wanted me to hookup a fan that had the installation instructions that said nothing about GFCI, or approval for use in the tub / shower space, where the homeowner had already mounted the fan in the tub / shower space. He'd read the instructions and was incredulous until I showed him.

 

[wwhitney]

Al / Wayne: do you throw away the power supply cord that came with your router (sitting on your desk), crack open the case and flex into it? 400.4 would require that with your interpretation.

So, the problem as I see it is that the terms "flexible cords" and "flexible cables" are not defined in the NEC.

I seem to recall an official source for some NEC guidance on seeking definitions of terms not defined in the NEC. Does that guidance just direct you to a standard dictionary, or does it suggest checking the informational sources in Appendix A first?

I picked up one wall wart for a router, and its output cord was labeled AWM. My understanding is that means it is covered by UL 758, not UL 817 or UL 62. As such, the informational note has no bearing on whether Article 400 applies to it.

Cheers, Wayne

 

[steve66]

Al / Wayne: do you throw away the power supply cord that came with your router (sitting on your desk), crack open the case and flex into it? 400.4 would require that with your interpretation.

You are talking about a router with a plug in transformer, correct?

I could be wrong, but I'm assuming "flexible cables, flexible cord sets, and power supply cords" covers line voltage cords. I don't think it applies to a low voltage power supply.

I don't have any hard evidence to support that conclusion. But I'm thinking that 120 volts needs to be in a listed wiring method, but there is probably some exception for low voltage??

If there is an exception for low voltage, then we don't have to call the cable from the power supply to the router a "cable" or "cord". It can just be a "wire", and 400 wouldn't apply.