conduit

[Speedy_Petey]

@dvalley

As I stated earlier, I see NM branch wiring on the exterior almost every day.

Here’s one from yesterday…

Well, pic #1 looks like it should have been going into the back of an exterior box. That wiring IS NOT “outside” in a case like that.
I do think someone forgot to mount the box and receptacle though. :mrgreen:

Pic #2 looks like UF. UF NM cable IS outdoor rated, for sunlight AND moisture.
NM-B is NOT.

[Speedy_Petey]

@dvalley

As I stated earlier, I see NM branch wiring on the exterior almost every day.

And this makes it right somehow?

[Greg_Fretwell]

I think the main problem with NM outside is the paper packing around the wires. It can wick water up into the cable and that might end up in a box inside.

MC uses a plastic wrapper so the aluminum stuff is usually “wet” listed

UF has no packing at all

[dvalley (David Valley, License #566 - CMI)]

@Speedy Petey

Well, pic #1 looks like it should have been going into the back of an exterior box. That wiring IS NOT “outside” in a case like that.
I do think someone forgot to mount the box and receptacle though. :mrgreen:

Pic #2 looks like UF. UF NM cable IS outdoor rated, for sunlight AND moisture.
NM-B is NOT.

So you are assuming that this was suppose to go into a weatherproof box. And if this location is not outside, then my name is Dick Tracy.

[dvalley (David Valley, License #566 - CMI)]

@Speedy Petey

Pic #2 looks like UF. UF NM cable IS outdoor rated, for sunlight AND moisture.
NM-B is NOT.

So that explains why I see this type of wiring on the exterior…It’s UF NM!!!

[Speedy_Petey]

@dvalley

So you are assuming that this was suppose to go into a weatherproof box. And if this location is not outside, then my name is Dick Tracy.

How are you Dick. Nice to meet you.

NM-B CAN most certainly come into the BACK of a properly sealed weathproof box installed out doors.
This installation DOES NOT expose any part of the cable to sunlight, excessive moisture or weather. IF installed properly!

[Speedy_Petey]

@dvalley

So that explains why I see this type of wiring on the exterior…It’s UF NM!!!

Yes, UF cable IS sunlight and moisture resistant. It is also a type of NM cable.

Don’t be fooled by grey or white either. I still have some 14/2 UF cable that is white, not grey.
The ONLY way to be sure what you are looking at is to read the sheath.

[jtedesco1 (Joe Tedesco)]

@Greg Fretwell

I think the main problem with NM outside is the paper packing around the wires. It can wick water up into the cable and that might end up in a box inside.

MC uses a plastic wrapper so the aluminum stuff is usually “wet” listed

UF has no packing at all

UF-B/3W/W/GRND

[dvalley (David Valley, License #566 - CMI)]

@Mike Whitt

Not trying to sound smart but feel the need to point out that Nonmetallic Cable (Romex) is not allowed to be installed on the exterior at all. It can not be installed exposed or in a conduit, it cain’t be installed outside at all.

Mike,

Did you see Speedy’s post…

@speedy

NM-B CAN most certainly come into the BACK of a properly sealed weathproof box installed out doors.
This installation DOES NOT expose any part of the cable to sunlight, excessive moisture or weather. IF installed properly!

[jfarsetta (Joe Farsetta)]

I the photo Joe T supplied, is the ground insulated or not.

Here’s the next question:

Can individual conductors installed in conduit be installed in exterior and/or damp locations. If so, then why?

This goes back to my question/statement regarding if romex can be installed in exterior or damp locations. If it is not suited, even when installed in conduit, then I ask why? Someone mentioned paper wrapping, which goes to my point regarding the ground conductor having its own insulation.

[Mike_Whitt]

@jfarsetta

I the photo Joe T supplied, is the ground insulated or not.

Here’s the next question:

Can individual conductors installed in conduit be installed in exterior and/or damp locations. If so, then why?

This goes back to my question/statement regarding if romex can be installed in exterior or damp locations. If it is not suited, even when installed in conduit, then I ask why? Someone mentioned paper wrapping, which goes to my point regarding the ground conductor having its own insulation.

To be installed in a wet location and outside is a wet location the conductor must comply with this section

310.8(C) Wet Locations. Insulated conductors and cables used in wet locations shall be
(1) Moisture-impervious metal-sheathed;
(2) Types MTW, RHW, RHW-2, TW, THW, THW-2, THHW, THHW-2, THWN, THWN-2, XHHW, XHHW-2, ZW; or
(3) Of a type listed for use in wet locations.

[Speedy_Petey]

Individual conductors can be installed in conduit outdoors if it is rated for it.
MOST new(er) THHN wiring is also dual rated as THHN/THWN. The “W” stands for wet.
**EDIT - Or better yet read Mike’s post above.

Again, the point of an “insulated” ground is not the point. UF cable has a bare ground, but it is within the sheath.

As to specifically why NM-B cannot be used wet, that is a call for the Mfg to make. I never really gave it a thought, I just always knew it was always a no-no.