Is this an adequate junction box wire job using a standard electric box? (pic included)

Question

I needed to splice a wire to repair nicked wire insulation, but I didn't feel like running to Lowe's just for a junction box. Instead, I used a regular electrical box.

The wire comes up from the floor and into the bottom of the box. The repair piece comes in from the top and will be wired up to the electrical outlet. I twisted the wires together with pliers and nutted them all up real tight. There are no exposed conductors outside the nuts.

I flipped on the power and, to my surprise, it worked! However, before I seal up the wall, I want to know if I did this right.

Answer 1

This is not really an answer (well it sort of is), I just wanted to clear some things up from the comments.

First those little tabs covering the holes in some plastic boxes, are NOT knockouts. They are clamps. In this case, however, they do appear to be knockouts.

If they were clamps you'd push the cable into the box past the clamps, then the clamps prevent the cable from being pulled out of the box. They can be a pain in the butt to work with, but they hold the cable fairly well.

Second, lets see what NEC 2008 says about securing the cable.

334.30 Securing and Supporting. Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (4 1⁄2 ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge. Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.

(A) Horizontal Runs Through Holes and Notches. In other than vertical runs, cables installed in accordance with 300.4 shall be considered to be supported and secured where such support does not exceed 1.4-m (4 1⁄2-ft) intervals and the nonmetallic-sheathed cable is securely fastened in place by an approved means within 300 mm (12 in.) of each box, cabinet, conduit body, or other nonmetallicsheathed cable termination.

FPN: See 314.17(C) for support where nonmetallic boxes are used.

(B) Unsupported Cables. Nonmetallic-sheathed cable shall be permitted to be unsupported where the cable:

(1) Is fished between access points through concealed spaces in finished buildings or structures and supporting is impracticable.

(2) Is not more than 1.4 m (4 1⁄2 ft) from the last point of cable support to the point of connection to a luminaire or other piece of electrical equipment and the cable and point of connection are within an accessible ceiling.

(C) Wiring Device Without a Separate Outlet Box. A wiring device identified for the use, without a separate outlet box, and incorporating an integral cable clamp shall be permitted where the cable is secured in place at intervals not exceeding 1.4 m (4 1⁄2 ft) and within 300 mm (12 in.) from the wiring device wall opening, and there shall be at least a 300 mm (12 in.) loop of unbroken cable or 150 mm (6 in.) of a cable end available on the interior side of the finished wall to permit replacement.

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314.17 Conductors Entering Boxes, Conduit Bodies, or Fittings. Conductors entering boxes, conduit bodies, or fittings shall be protected from abrasion and shall comply with 314.17(A) through (D).

(C) Nonmetallic Boxes and Conduit Bodies. Nonmetallic boxes and conduit bodies shall be suitable for the lowest temperature-rated conductor entering the box. Where nonmetallic boxes and conduit bodies are used with messengersupported wiring, open wiring on insulators, or concealed knob-and-tube wiring, the conductors shall enter the box through individual holes. Where flexible tubing is used to enclose the conductors, the tubing shall extend from the last insulating support to not less than 6 mm (1⁄4 in.) inside the box and beyond any cable clamp. Where nonmetallicsheathed cable or multiconductor Type UF cable is used, the sheath shall extend not less than 6 mm (1⁄4 in.) inside the box and beyond any cable clamp. In all instances, all permitted wiring methods shall be secured to the boxes.

Exception: Where nonmetallic-sheathed cable or multiconductor Type UF cable is used with single gang boxes not larger than a nominal size 57 mm × 100 mm (2 1⁄4 in.× 4 in.) mounted in walls or ceilings, and where the cable is fastened within 200 mm (8 in.) of the box measured along the sheath and where the sheath extends through a cable knockout not less than 6 mm (1⁄4 in.), securing the cable to the box shall not be required. Multiple cable entries shall be permitted in a single cable knockout opening.

So what does this all mean?

334.30 says we have to secure the cable every 4 1/2' and 12" from each box, however, 334.30(B)(1) says if we are fishing the cable through finished surfaces the cable does not have to be secured. So we can have an unsecured cable in the wall, but 314.17(C) says if we are using a nonmetallic box the cable must be secured to the box (this is where the clamps come in). The exception to this rule, is if the cable is secured within 8" of the box. If we secure the cable within 8" of the box, we don't have to secure the cable to the box.

Answer 2

It looks good, but the romex sheath on the bottom cable has to come into the box for it to be correct. I can't see that area to make that call, but if you have sheath then you have done good.

Answer 3

Uh - you can't seal up the wall. You have to leave that junction box accessible. Right guys?

Answer 4

Once again, the box he is using is a "new work" "handy box" it is only a knockout and not a clamp! Therefore the 8" staple rule applies! With this type of box it is required to staple within 8", a box with a clamp is 12"! An "old work" Handy box would have a clamp as well as plaster ears with a screw device to secure the box

Notice the "Clamp" type box Notice the "Knockout" type box

See Tester101 code quote "314.17 C Exception... Says it all! Looking at his picture, I see no clamp on the wire! If it was there, it aint now!

Answer 5

"I needed to splice a wire to repair nicked wire insulation...."

I appreciate this discussion, but I will contend that there was NO NECESSITY to cut the cable and try to put it in a box. In fact, I think there is much more risky to have done so. Unless the conductor was appreciably damaged, I contend that simple application of wraps of electrical tape which adequately protected the conductor(s) from shorting-out to one another, and/or the [metal] building, metallic piping, etc., or else presents any kind of shock hazard to building occupants should be proper to use.

I was taught, and my experiences in Fire Investigation have proved, that Good Terminations are the most important things an Electrician does day-in and day-out. This is of course aside from proper sizing of circuit-elements such as breakers and wires. Splices in a circuit are therefore much worse to do than a simple insulation repair.