improper wire bundle?

[ccarrington]

This it a photo of a brand new SEC... the home is not yet occupied by the owner. When I pulled the SEC cover off, I discovered all these wires jammed into this one opening. I wanted a second or third opinion but feel this is clearly a case of improperly "bundled" wires. This home has an an electric heat pump and aux electric furnace whose wires also pass through this point. My feeling is that heat may not be able to properly dissipate this bundle point. What do you all think about this?

Thanks

[tdietrich1]

That is lazy work. Nipple-heads!

Do you have more photos? Typical dirtbags don't limit their incompetency to one thing, guessing the rest of the panel is fudged up too.

tom

[rromoser]

Overheating is definitely a cause for concern here. NEC Table 310.15(B)(2)(a) shows derating of conductors when there is more than 3 in a raceway. A 12 awg. copper THHN insulation copper conductor is good for 25 amps with not more than 3 wires in the raceway. When a raceway exceeds 20 wires it needs to be derated to 45% of 25, or 11.25 amps. Taking it one step farther if the number of conductors exceed 40, it derates to 35% or 8.75 amps. All of this derating is to allow for cooling of the conductors. I'd take a real close look at the whole electrical system. When I was wiring houses we were told if nothing else, make the panel look good, most inspectors will stop looking further if it looks good.
Attached is the panel in my house I did 17 yrs. ago

[rromoser]

Oops, the pictures didn't post. Was my first attempt to send pics. Help.

[tdietrich1]

Originally Posted by rromoser

NEC Table 310.15(B)(2)(a)

What if it's a short nipple?

tom

P.S. The photos don't lie, show me the snapshots.

[rromoser]

A short nipple (< 24" ) only allows for a higher percentage (60%)of conductor fill instead of 40%. That doesn't change the derating factor.

[jkormos]

Looks as if the insulation on the green wire in the middle of the bunch is melted a bit?? Or it appears that way from the photo

[rromoser]

It appears to be green phasing tape to identify the black wire as a ground.

[brian winkle]

Originally Posted by rromoser

A short nipple (< 24" ) only allows for a higher percentage (60%)of conductor fill instead of 40%. That doesn't change the derating factor.

de rating does not apply to conductors in nipples of 24" or less.

[ccarrington]

Thank you for your inputs, I was aware of the (conduit) fill requirement of 40% of cross sectional area; however my concern is that I can’t tell if the wires actually enter a conduit. This is actually a separate concern… They do all bundle together however at this point and go up to the attic, and essentially the NM cables are “bundled” for at least 3 to 4 feet in that run… “Bundled” means that some of the wires are surrounded by many other wires, and can not dissipate heat well to the surrounding air. This attic is located in central Texas (very hot), the roof covering is black (increased solar heat loading) and the attic is marginally vented… I’ll get more photos today.

I will be going back today, and will get more photos… Anyway, you are correct about poor workmanship in general… this (new) house was suppose to be finished and close prior to thanksgiving, pushed to 19 Dec, pushed to 27 Dec, pushed to 10 Jan… I did get hired yesterday to perform weekly progress inspections for the client… I also found lots of beer cans in the attic left by drunk electricians, who only speak Spanish… I will put on my INS/ border patrol jacket and walk through the addition today to see if I can cause a work stoppage…

Thanks guys

[tdietrich1]

Originally Posted by ccarrington

I also found lots of beer cans in the attic left by drunk electricians,

I do my best work drunk, so don't beat them up.

BTW, if you are doing weekly progress reports, take a peek in any open vent spaces. I use to do some vent duct cleaning, and it was amazing how many beer cans can be hidden in them. Oh and I suspect they were from the HVAC guys since with the cans were left-over thick zip-ties.

Also, inform the buyers about the 'issues' before closing, might want to get code enforcement involved early.

tom

[Paul W. Abernathy]

I agree with Brian here in regards to the nipple as for derating ampacity -

Exception No. 3: Derating factors shall not apply to conductors

in nipples having a length not exceeding 600 mm
(24 in.).


However....Chapter 9, Table 1 (notes 4) states

(4) Where conduit or tubing nipples having a maximum

length not to exceed 600 mm (24 in.) are installed between
boxes, cabinets, and similar enclosures, the
nipples shall be permitted to be filled to 60 percent of
their total cross-sectional area, and 310.15(B)(2)(a) adjustment
factors need not apply to this condition.

However.....with this in mind....



Note 2 of the SAME table says the following.." Conduit fill calculations are not intended to apply to short sections of conduit that are used only to protect exposed wires [such as Romex] from physical damage. Conduit fill calculations pertain only to certain wiring designed sections that is substantially conduit in design." NEC Chapter 9 Notes to tables Note 2

Now are we talking about all NM Cables being sleeved in conduit into this panel for protection..?...well view NEC Article 312.15(C) as I will post it..

(C) Cables.

Where cable is used, each cable shall be secured
to the cabinet, cutout box, or meter socket enclosure.

Exception: Cables with entirely nonmetallic sheaths shall
be permitted to enter the top of a surface-mounted enclosure
through one or more nonflexible raceways not less
than 450 mm (18 in.) and not more than 3.0 m (10 ft) in
length, provided all of the following conditions are met:
(a) Each cable is fastened within 300 mm (12 in.),
measured along the sheath, of the outer end of the raceway.
(b) The raceway extends directly above the enclosure
and does not penetrate a structural ceiling.
(c) A fitting is provided on each end of the raceway to
protect the cable(s) from abrasion and the fittings remain
accessible after installation.
(d) The raceway is sealed or plugged at the outer end
using approved means so as to prevent access to the enclosure
through the raceway.
(e) The cable sheath is continuous through the raceway
and extends into the enclosure beyond the fitting not
less than 6 mm (

1.4 in.).
(f) The raceway is fastened at its outer end and at
other points in accordance with the applicable article.
(g) Where installed as conduit or tubing, the allowable
cable fill does not exceed that permitted for complete conduit
or tubing systems by Table 1 of Chapter 9 of this Code
and all applicable notes thereto.

FPN: See Table 1 in Chapter 9, including Note 9, for allowable
cable fill in circular raceways. See 310.15(B)(2)(a) for
required ampacity reductions for multiple cables installed in a
common raceway.

So are ALL these items MET....if not........not allowed and each cable must be secured when entering the enclosure.

Hope this helps..if not just ask and I will explain more.....

For Educational Purposes Only.....Paulright Protected...