Romex under patio eave...Question

dnasser · April 25, 2011, 6:54pm

This is for exterior lights connected to eaves…
Should the wire runs be in conduit?

jpope · April 25, 2011, 7:11pm

“Romex” (NM) does not belong in conduit, and it is not allowed for use in damp/wet locations.

So the answer to your question is “no,” but this wiring method is improper for exterior lighting.

belliott · April 25, 2011, 7:20pm

What Jeff said as you should never double insulate conductors.

rmeier2 · April 25, 2011, 8:12pm

I agree that standard NM cable is not permitted in wet or damp locations. NM cable is permitted to be pulled into a raceway providing that the allowable raceway fill is followed.

jgromkoski · April 25, 2011, 8:14pm

I have seen Romex rated for exterior use.

dnasser · April 25, 2011, 8:21pm

Thanks Jeff…Im will use this statement…

( wiring method is improper for exterior lighting. )

rmeier2 · April 25, 2011, 8:31pm

You’re correct, there is a cable, NMC that is listed for damp and wet locations but it’s a pretty rare cable type .

II. Installation
334.10 Uses Permitted.
Type NM, Type NMC, and Type NMS cables shall be permitted to be used in the following:
(1) One- and two-family dwellings.
(2) Multifamily dwellings permitted to be of Types III, IV, and V construction except as prohibited in 334.12.
(3) Other structures permitted to be of Types III, IV, and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire-rated assemblies.
FPN No. 1: Types of building construction and occupancy classifications are defined in NFPA 220-2006, Standard on Types of Building Construction, or the applicable building code, or both.
FPN No. 2: See Annex E for determination of building types [NFPA 220, Table 3-1].
(4) Cable trays in structures permitted to be Types III, IV, or V where the cables are identified for the use.
FPN: See 310.10 for temperature limitation of conductors.
(A) Type NM. Type NM cable shall be permitted as follows:
(1) For both exposed and concealed work in normally dry locations except as prohibited in 334.10(3)
(2) To be installed or fished in air voids in masonry block or tile walls
(B) Type NMC. Type NMC cable shall be permitted as follows:
(1) For both exposed and concealed work in dry, moist, damp, or corrosive locations, except as prohibited by 334.10(3)
(2) In outside and inside walls of masonry block or tile
(3) In a shallow chase in masonry, concrete, or adobe protected against nails or screws by a steel plate at least 1.59 mm ( in.) thick and covered with plaster, adobe, or similar finish

jjonas · April 25, 2011, 8:39pm

jpope · April 25, 2011, 9:46pm

As have I, but chances are slim to none that the right type is in use here.

tspargo · April 26, 2011, 12:50am

I gotta agree… just about anytime we see NM on the exterior, or in a garage or a host of other places… it’s likely wrong in some way shape or form.

What you think about a CA checklist for NM and/or visible wiring practices Jeff? Pics of correct/incorrect EMT fittings and so on… just the basics/common stuff. Most places we see sched 40 should be RMC and so on.

Just an idea.

jpope · April 26, 2011, 1:43am

What are you waiting for Tim? Get it started and I’ll be happy to contribute

rray · April 26, 2011, 9:10am

Our electricians here (as well as the courts) don’t mind if it’s unprotected as long as it’s seven feet or above. If it’s lower than that, they want it protected, usually in a raceway.

rmeier2 · April 26, 2011, 11:02am

What do the courts have to do with it?

rray · April 26, 2011, 2:50pm

Lawsuit that actually went to court rather than being settled out of court.

jgromkoski · April 26, 2011, 8:01pm

How about this arrangement?

Jim_Port · April 26, 2011, 8:14pm

Hard to tell if the proper cable type or WP connector was used.

The PVC is acting as a sleeve either for protection or neatness or both.

jpope · April 26, 2011, 8:20pm

The NM must be rated for UV and damp/wet locations, or it’s no good. Again, chances are slim to none that it is the proper type.

jgromkoski · April 26, 2011, 8:32pm

Its a steel conduit, not PVC.
Is the fact that it’s in a steel conduit an issue as well?

rmeier2 · April 26, 2011, 8:39pm

Steel conduit is permitted as a sleeve for NM cable.

jgromkoski · April 26, 2011, 9:02pm

Robert, can you please clarify for me. I thought I saw that NM cannot be installed in a conduit. Thanks.