Outer Sheath on NM Cable

[Little Bill]

Do you think the outer sheath on 6-2 NM is any stronger/thicker than say, 12-2 NM?

I was just thinking about that and wondered if the larger size NM would keep out moisture better than the smaller 14-2 or 12-2.

I saw some 6-2 inside a conduit the other day. It was under a deck that also had a covered roof. I was just wondering if the 6-2 NM would hold up to whatever moisture would/could get in the conduit.

 

[hurk27]

Doesn't really matter as it is still a code violation, while I would assume it is thicker if it isn't listed for wet locations it's not allowed, I have seen 14/2 in outside conduit and has been there for years and still going strong?

 

[LEO2854]

Do you think the outer sheath on 6-2 NM is any stronger/thicker than say, 12-2 NM?

I was just thinking about that and wondered if the larger size NM would keep out moisture better than the smaller 14-2 or 12-2.

I saw some 6-2 inside a conduit the other day. It was under a deck that also had a covered roof. I was just wondering if the 6-2 NM would hold up to whatever moisture would/could get in the conduit.

I'll bet it's about the same?

 

[ActionDave]

I was just thinking about that and wondered if the larger size NM would keep out moisture better than the smaller 14-2 or 12-2.

I saw some 6-2 inside a conduit the other day. It was under a deck that also had a covered roof. I was just wondering if the 6-2 NM would hold up to whatever moisture would/could get in the conduit.

I don't think the sheathing stops water at all. I really don't think the wire will fail. It is thhn IMO.
A more important question might be, "Why would somebody pull 6-2 Romex in a conduit and run it to a hot tub?" Six romex has to be the worst. I would rather do my own root cannel with my root-zip than land that stuff in a hot tub.

Come to think of it, how did 6-2 work? Wouldn't you need 6-3?

 

[Dennis Alwon]

Not all tubs need a neutral and we don't know for certain that the wire in the NM is dual rated. I also think it will last as long as you do.

 

[Little Bill]

I don't think the sheathing stops water at all. I really don't think the wire will fail. It is thhn IMO.
A more important question might be, "Why would somebody pull 6-2 Romex in a conduit and run it to a hot tub?" Six romex has to be the worst. I would rather do my own root cannel with my root-zip than land that stuff in a hot tub.

Come to think of it, how did 6-2 work? Wouldn't you need 6-3?

You would need 6-3 for most hot tubs. I did install (4-wire) 6-3 THHN W/ #10 egc, I just saw this while installing mine.

 

[PetrosA]

You would need 6-3 for most hot tubs. I did install (4-wire) 6-3 THHN W/ #10 egc, I just saw this while installing mine.

The tubs I've done have called for a full size ground in the installation instructions, so NM doesn't fly anyway.

 

[kwired]

NM cable has paper fillers that are absorbent - probably the number one reason for not being wet location rated.

Next step up is UF cable - very similar in construction but with no paper fillers within the cable - probably the number one reason it is rated for wet locations.

I find that 8 THHN is rated for 50 amps and is easier to install to a hot tub needing a 50 amp circuit - at least for the final section of the run. NM may be easier if there is a long run or some fishing to do from the source to the disconnect.

 

[Little Bill]

NM cable has paper fillers that are absorbent - probably the number one reason for not being wet location rated.

Next step up is UF cable - very similar in construction but with no paper fillers within the cable - probably the number one reason it is rated for wet locations.

I find that 8 THHN is rated for 50 amps and is easier to install to a hot tub needing a 50 amp circuit - at least for the final section of the run. NM may be easier if there is a long run or some fishing to do from the source to the disconnect.

All the tubs I have done that required 50A also required #6 be run. I would like to use #8 since most had some **xxLL** install the connection terminals about 1-1/2" from where the conductors enter the control box. Not much room at all to terminate the #6.
I don't know why they spec #6 when #8 is good enough for 50A per Table 310.16.

 

[electrofelon]

I don't know why they spec #6 when #8 is good enough for 50A per Table 310.16.

Yeah I am getting sick of these manufacturers requiring stupid things in their instructions. I assume that they often think these things are code. The last hot tub I did I got hit with the "50 amp, but use 6 awg wire", and the last hydro-message tub told me to run the bonding wire back to the service

 

[kwired]

All the tubs I have done that required 50A also required #6 be run. I would like to use #8 since most had some **xxLL** install the connection terminals about 1-1/2" from where the conductors enter the control box. Not much room at all to terminate the #6.
I don't know why they spec #6 when #8 is good enough for 50A per Table 310.16.

I haven't hooked up a tub in a while, but I think I do recall a few that required 6AWG - and they left little space to bend that size of a conductor

 

[jwelectric]

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling. I don't see anything about a manual listed here. I think that the instructions will be found at the same place that the listing is found.

 

[kwired]

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling. I don't see anything about a manual listed here. I think that the instructions will be found at the same place that the listing is found.

So for every piece of listed equipment we run into we need to find the listing and any instructions that go with it instead of relying on any instructions that shipped with the equipment?

 

[growler]

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling. I don't see anything about a manual listed here. I think that the instructions will be found at the same place that the listing is found.

So for every piece of listed equipment we run into we need to find the listing and any instructions that go with it instead of relying on any instructions that shipped with the equipment?

I thought the installation manual was part of the instructions that go with the listing.


Are we trying to say that when they sent a piece of equipment to Underwritters Laboratories for testing and to get a listing that they provided a different set of instructions? :slaphead:

 

[kwired]

I thought the installation manual was part of the instructions that go with the listing.


Are we trying to say that when they sent a piece of equipment to Underwritters Laboratories for testing and to get a listing that they provided a different set of instructions? :slaphead:

I kind of thought the installation manual was part of instructions that go with listing. But when it comes the great care taken to be clear and accurate when writing many instruction manuals these days I really don't know how they could approve the instructions portion of getting a listing. I can say that those instructions likely did not get looked at if they were included with any testing.

 

[wirebender]

A lot of the instructions nowadays are obviously written by persons with a very weak grasp of the English language.

 

[jwelectric]

A good example of installation instructions that are included in the listing and labeling is a stand-alone generator, the ones with the receptacles on the frame of the generator.

There are many different items on the market to install one to one?s home but the instructions for doing so can be found in the UL White Book under FTCN.

According to the installation instructions included with the listing of these generators the only way to connect one to one?s home is to do so as a SDS.

 

[kwired]

A good example of installation instructions that are included in the listing and labeling is a stand-alone generator, the ones with the receptacles on the frame of the generator.

There are many different items on the market to install one to one?s home but the instructions for doing so can be found in the UL White Book under FTCN.

According to the installation instructions included with the listing of these generators the only way to connect one to one?s home is to do so as a SDS.

I know this is maybe being nit picky, but some of the details involved here come down to interpretation of certain key words so, do you install a portable generator or do you just connect to it?

 

[electrofelon]

A good example of installation instructions that are included in the listing and labeling is a stand-alone generator, the ones with the receptacles on the frame of the generator.

There are many different items on the market to install one to one?s home but the instructions for doing so can be found in the UL White Book under FTCN.

According to the installation instructions included with the listing of these generators the only way to connect one to one?s home is to do so as a SDS.

That is odd because most portable generators that I have seen have the neutral "floating" which implies installation as a non-SDS. ~confused~

 

[kwired]

That is odd because most portable generators that I have seen have the neutral "floating" which implies installation as a non-SDS. ~confused~

Same here.