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To a large degree, Randy's right. I never see the stuff you're talking about. The only thing I see is conduit in all it's forms.

This NM stuff has me baffled.

So let me get this straight........the problem is UF in conduit(?). THWN is correct(?).

Sure. The problem is that UF isn't one of the approved wiring methods for this situation. Neither is EMT, by the way. The fact that it's "protected" by conduit doesn't matter.

Would THHN be OK?

That would depend on the location. If this were a dry or damp location, THHN would be fine. But it sounds like the conduit is in a wet location. If so then the interior of the conduit is also considered a wet location and you'd have to use wires that had the letter W printed on them somewhere.

That said, I can't see why a length of UF inside conduit would be a problem in this case. I know it doesn't comply with 680.21. It just doesn't feel like a rightous call in this case. What rational is at work here?

- Jim Katen, Oregon

- Jim Katen, Oregon

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How 'bout LFMC, or LFNC?

Sealtight? I know I said "conduit", but I wasn't thinking EMT, I was thinking waterproof flex.

I understand how it's not right, but in this case, does it really matter other than to show off super fine tuned-ness?

I mean, what possible thing could go wrong other than Jeff being the AHJ and making you change it?

FTR, I'd have never found that in a million years.......

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

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  • 2 weeks later...

*Hot tub installed outdoors.

*50A GFCI breaker in main panel inside the home.

*6/3 NM runs inside the home and terminated inside a properly placed disconnect within site of the hot tub.

*From the disco 6/3 UF is properly protected and runs to the hot tub.

All wiring is correct and the hot tub functions.

Is there a problem with this install?

Sorry for the late post, but I just joined.

NM cable is permitted inside the dwelling only. The disconnect is outside.

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

NEC 110.14©(1)(a)(1) states;

(a) Termination provisions of equipment for circuits

rated 100 amperes or less, or marked for 14 AWG through

1 AWG conductors, shall be used only for one of the following:

(1) Conductors rated 60°C (140°F).

#8 is rated 40A @ 60C

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OK, now that I have your attention, lets break this down.

What run is in violation?:

1) The NM from the main panel to the disconnect

2) The UF from the disco to the hot tub

3) Both runs

We have to determine what the "branch circuit" is.

1) NM is a violation as stated in my previous post.

2) UF is also a violation.

680.40 General. Electrical installations at spas and hot

tubs shall comply with the provisions of Part I and Part IV

of this article.

680.25 (B) states;

(B) Grounding. An equipment grounding conductor shall

be installed with the feeder conductors between the grounding

terminal of the pool equipment panelboard and the

grounding terminal of the applicable service equipment or

source of a separately derived system. For other than (1)

existing feeders covered in 680.25(A), Exception, or (2)

feeders to separate buildings that do not utilize an insulated

equipment grounding conductor in accordance with

680.25(B)(2), this equipment grounding conductor shall be

insulated.

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

NEC 110.14©(1)(a)(1) states;

(a) Termination provisions of equipment for circuits

rated 100 amperes or less, or marked for 14 AWG through

1 AWG conductors, shall be used only for one of the following:

(1) Conductors rated 60°C (140°F).

#8 is rated 40A @ 60C

You left out this part:

(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.

(4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.

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NM into the back of the disco is fine. This is no different than having NM feed an exterior light or receptacle when coming into the back of the box. This would not be considered an exterior.

680.21(A)(4) is specific and states;

(4) One-Family Dwellings. In the interior of dwelling

units, or in the interior of accessory buildings associated

with a dwelling unit, any of the wiring methods recognized

in Chapter 3 of this Code that comply with the provisions

of this section shall be permitted. Where run in a

cable assembly, the equipment grounding conductor shall

be permitted to be uninsulated, but it shall be enclosed

within the outer sheath of the cable assembly.

680.3 states;

680.3 Other Articles. Except as modified by this article,

wiring and equipment in or adjacent to pools and fountains

shall comply with other applicable provisions of this Code,

including those provisions identified in Table 680.3.

No where in 680 does it permit NM cable outside the dwelling.

Also, 680 has nothing to do with outside lighting fixtures and receptacles in any other area except the pool.

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

NEC 110.14©(1)(a)(1) states;

(a) Termination provisions of equipment for circuits

rated 100 amperes or less, or marked for 14 AWG through

1 AWG conductors, shall be used only for one of the following:

(1) Conductors rated 60°C (140°F).

#8 is rated 40A @ 60C

You left out this part:

(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.

(4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.

That means all terminations including wirenuts.

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NM into the back of the disco is fine. This is no different than having NM feed an exterior light or receptacle when coming into the back of the box. This would not be considered an exterior.

680.21(A)(4) is specific and states;

(4) One-Family Dwellings. In the interior of dwelling

units, or in the interior of accessory buildings associated

with a dwelling unit, any of the wiring methods recognized

in Chapter 3 of this Code that comply with the provisions

of this section shall be permitted. Where run in a

cable assembly, the equipment grounding conductor shall

be permitted to be uninsulated, but it shall be enclosed

within the outer sheath of the cable assembly.

680.3 states;

680.3 Other Articles. Except as modified by this article,

wiring and equipment in or adjacent to pools and fountains

shall comply with other applicable provisions of this Code,

including those provisions identified in Table 680.3.

No where in 680 does it permit NM cable outside the dwelling.

Nor does it prohibit it. The first section you quoted just says that, in the interior, X is permitted. That's not a prohibition. This is not the section that you want to quote to support your argument.

If you want to argue against NM running into an outdoor disconnect box, you might avoid stating that NM is only allowed inside a dwelling. That's really hard to back up. Instead, I'd concentrate on 334.12(B)(4). It prohibits NM in wet or damp locations. Armed with that prohibition, you could say that the NM shouldn't run to the disconnect box because the disconnect box is supposed to be mounted 1/4" away from the outside wall (312.2) and the NM would necessarily have to pass through that space.

For the situation in the original post, I think your previous argument, citing 680.25(B), was spot on if there's a breaker in the disconnect box, but I think that most folks didn't catch it. That argument says that the cable that runs to the disconnect is, technically, a feeder (because it comes before the final overcurrent protection device). Because this is a hot tub, there are special rules for feeders that require their grounding conductor to be insulated. (With some exceptions that don't apply here.)

- Jim Katen, Oregon

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NM into the back of the disco is fine.

Well, it's nearly a universal practice, but for pools & spas the EGC should be insulated if there's a breaker in the disconnect. And for things other than pools & spas there's still that pesky 1/4" air space that's considered a wet location. It's not the end of the world, I know, but it's still, technically, wrong.

This is no different than having NM feed an exterior light or receptacle when coming into the back of the box. This would not be considered an exterior.

There are actually two differences. First, the disconnect box is surface mounted, while the light & receptacle boxes are recessed. Second, the disconnect serves a spa, which brings in a whole set of requirments from Article 680 that wouldn't apply to most other exterior lights & receptacles.

- Jim Katen, Oregon

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NM into the back of the disco is fine. This is no different than having NM feed an exterior light or receptacle when coming into the back of the box. This would not be considered an exterior.

680.21(A)(4) is specific and states;

(4) One-Family Dwellings. In the interior of dwelling

units, or in the interior of accessory buildings associated

with a dwelling unit, any of the wiring methods recognized

in Chapter 3 of this Code that comply with the provisions

of this section shall be permitted. Where run in a

cable assembly, the equipment grounding conductor shall

be permitted to be uninsulated, but it shall be enclosed

within the outer sheath of the cable assembly.

680.3 states;

680.3 Other Articles. Except as modified by this article,

wiring and equipment in or adjacent to pools and fountains

shall comply with other applicable provisions of this Code,

including those provisions identified in Table 680.3.

No where in 680 does it permit NM cable outside the dwelling.

Nor does it prohibit it. The first section you quoted just says that, in the interior, X is permitted. That's not a prohibition. This is not the section that you want to quote to support your argument.

If you want to argue against NM running into an outdoor disconnect box, you might avoid stating that NM is only allowed inside a dwelling. That's really hard to back up. Instead, I'd concentrate on 334.12(B)(4). It prohibits NM in wet or damp locations. Armed with that prohibition, you could say that the NM shouldn't run to the disconnect box because the disconnect box is supposed to be mounted 1/4" away from the outside wall (312.2) and the NM would necessarily have to pass through that space.

For the situation in the original post, I think your previous argument, citing 680.25(B), was spot on if there's a breaker in the disconnect box, but I think that most folks didn't catch it. That argument says that the cable that runs to the disconnect is, technically, a feeder (because it comes before the final overcurrent protection device). Because this is a hot tub, there are special rules for feeders that require their grounding conductor to be insulated. (With some exceptions that don't apply here.)

- Jim Katen, Oregon

I think 680.21(A)(4) is clear enough. Once the building envelope is pierced and the NM cable enteres the disconnect, it is outside the building. Weather it is 1/16" or 16", it is outside. Enough said.

"Nor does it prohibit it". Since 680.21(A)(4) clearly reads interior how could that be interpreted any other way?

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

NEC 110.14©(1)(a)(1) states;

(a) Termination provisions of equipment for circuits

rated 100 amperes or less, or marked for 14 AWG through

1 AWG conductors, shall be used only for one of the following:

(1) Conductors rated 60°C (140°F).

#8 is rated 40A @ 60C

You left out this part:

(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.

(4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.

110.3(B) reads;

(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

The UL White Book reads;

NONMETALLIC-SHEATHED CABLE

(PWVX)

USE

This category covers Types NM-B and NMC-B nonmetallic-sheathed

cable, rated 600 V, intended for use in accordance with Article 334 of

ANSI/NFPA 70, ‘‘National Electrical Code’’ (NEC), and Listed in copper

sizes 14 to 2 AWG inclusive and aluminum or copper-clad aluminum

sizes 12 to 2 AWG inclusive. This cable contains conductors rated 90°C; however, the ampacities of the cable are those of 60°C conductors as specified in Article 334 and Table 310.16 of the NEC.

ALthough NM cable is constructed using 90C conductors, the ampacities shall be 60C.

#8 NM cable is rated 40A. Period.

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. . . I think 680.21(A)(4) is clear enough. Once the building envelope is pierced and the NM cable enteres the disconnect, it is outside the building. Weather it is 1/16" or 16", it is outside. Enough said.

680.21(A)(4) is clear, but it doesn't say what you want it to say. It simply saying that, in the interior of a dwelling, X is permitted. It doesn't say what's not permitted and it doesn't say what is or isn't permitted outside a dwelling. This section does not support your argument. Enough said.

"Nor does it prohibit it". Since 680.21(A)(4) clearly reads interior how could that be interpreted any other way?

Because it doesn't contain any prohibition.

- Jim Katen, Oregon

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Service switch not less than five feet?

Yes Erik with a K, NOT LESS THAN therefore it needs to be 5' or MORE away from the hot tub.

The link you posted above does not apply because this is a SFR and the answer in the link does not qualify SFR.

Most of these jobs are with PVC and THWN pulled inside.

I just did a job for my aunt like this 2 weeks ago. I pulled NM inside the house and from the exterior disco to the hot tub I pulled THWN, 6/3NM inside the house and #8 THWN outside the house and was able to maintain the 50A required rating..

NEC 110.14©(1)(a)(1) states;

(a) Termination provisions of equipment for circuits

rated 100 amperes or less, or marked for 14 AWG through

1 AWG conductors, shall be used only for one of the following:

(1) Conductors rated 60°C (140°F).

#8 is rated 40A @ 60C

You left out this part:

(3) Conductors with higher temperature ratings if the equipment is listed and identified for use with such conductors.

(4) For motors marked with design letters B, C, or D, conductors having an insulation rating of 75°C (167°F) or higher shall be permitted to be used, provided the ampacity of such conductors does not exceed the 75°C (167°F) ampacity.

110.3(B) reads;

(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

The UL White Book reads;

NONMETALLIC-SHEATHED CABLE

(PWVX)

USE

This category covers Types NM-B and NMC-B nonmetallic-sheathed

cable, rated 600 V, intended for use in accordance with Article 334 of

ANSI/NFPA 70, ‘‘National Electrical Code’’ (NEC), and Listed in copper

sizes 14 to 2 AWG inclusive and aluminum or copper-clad aluminum

sizes 12 to 2 AWG inclusive. This cable contains conductors rated 90°C; however, the ampacities of the cable are those of 60°C conductors as specified in Article 334 and Table 310.16 of the NEC.

ALthough NM cable is constructed using 90C conductors, the ampacities shall be 60C.

#8 NM cable is rated 40A. Period.

Um, dude, no one is saying otherwise. Of course NM is always rated at 60 degrees. You don't have to go to the white book for that, it's right there in 334.80.

Read Jeff's comment again. He used #6 NM indoors and #8 THWN outdoors. As long as all of the connection points are rated for 75 degrees, his installation is fine.

- Jim Katen, Oregon

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. . . I think 680.21(A)(4) is clear enough. Once the building envelope is pierced and the NM cable enteres the disconnect, it is outside the building. Weather it is 1/16" or 16", it is outside. Enough said.

680.21(A)(4) is clear, but it doesn't say what you want it to say. It simply saying that, in the interior of a dwelling, X is permitted. It doesn't say what's not permitted and it doesn't say what is or isn't permitted outside a dwelling. This section does not support your argument. Enough said.

"Nor does it prohibit it". Since 680.21(A)(4) clearly reads interior how could that be interpreted any other way?

Because it doesn't contain any prohibition.

- Jim Katen, Oregon

Um "Dude",

Let me get this right. You are stating that since the NEC doesn't read that "NM cable is prohibited" it is acceptable to install NM cable outside the dwelling unit to the disconnect. However, the NEC clearly reads that NM cable is permissible "in the interior of dwelling units". Your argument is absurd. What code book are you looking at?

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Your interpretation of interior is the most rigid I have seen. I have yet to see an code inspector have an issue with NM into the back of a disco. What would you propose, a splice box on the inside of the wall and switch wiring methods? Where do you see as the limit of the interior; is it the face of the drywall or the vinyl siding?

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