More Hacking - ECN Electrical Forums

Submitted without a name:

I work at a newspaper office in central California. I am a computer
geek, not an electrican, but after seeing many of the scary photos on
the violation pictures forum, I was motivated to look around the old
building I work in to see if our 1930's-era structure had any dangerous
hazards, as it has been added-on to and had numerous modifications
throughout the years by countless people. I looked inside a crawl
space
and lo and behold, I found a major hack job right under our own roof --
not to mention a potential fire hazard. Also, other than the obvious
unsuspended NM cable, lack of a grounding conductor in the conduit,
overfilled junction box without a cover, and lack of wire nuts on the
splices -- do you notice anything else wrong with this picture? P.S.-
this mess has been in use for over 25 years!

[Linked Image]

Is it my monitor, or are all the wires the same color?

Mike (mamills)

Picky, picky, picky. That mess has served well for 25 years and you're complaining! Emt can serve as the grounding conductor, the box doesn't look overfilled to me and who knows, there's probably crimp connectors under that tape. Looks like another beautiful job by an in-house maintenance mechanic.

Well, I wouldn't say it's a beautiful job, but I've seen worse. In Mexico, where all wires seem to be white, this would be first class. I don't see a ground connection on the NM-- that's a concern. Mighty thoughtful of the hacker to use NM connectors, though.

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Emt can serve as the grounding conductor

Well, yes it can, but not if locknuts are missing (see the connector on top). It is always in the interest of safety to add a separate grounding conductor, as many jurisdictions now require. That way, when the maintenance guys do their worst, you might still have grounding continuity.

The box offsets in the EMT look nice. This was competently installed originally, before it was monkeyed with.

I dunno, I might be more inclined to worry about the pile of kindling stored under this box.

Mike,

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Is it my monitor, or are all the wires the same color?

No worries with your monitor, mate, unless both of our monitors are broken.
Where did this cable come from?.
Seems like bargain basement stuff.

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Emt can serve as the grounding conductor

My experience of metallic conduits, is that you never rely on any metallic conduits as part of the Fault Path.

Isn't there a rule against stringing romex thru the air like that?

I am the original poster, but I forgot to send my username in my email. I'm not an electrician, but I find numerous safety hazards and violations in this installation:

1. No wire nuts used to connect wires together (violation)

2. Ground wires on NM cable have been cut off and are not bonded to the conduit system (violation).

3. Overfilled 21 cu. in. metal junction box. (Violation) This box has a total of ten 12 ga. current-carrying conductors. For box-fill requirements, the code requries 2.25 cu. in per 12 ga. conductor. Add one extra conductor for the illegally cut-off ground wires on the NM cable, and the total is 11 conductors (2.25 x 11 = 24.75 Cu. In)

4. Ungrounded NM cable feeds 3 prong grounding-type ceiling outlets (violation), controlled by wall switch to power fluorescent lights in store room.

5. Use of white wire for hot conductor, without clear markings to differentiate from neutral conductor (violation).

6. Lack of grounding conductor, relying solely on conduit.

7. No cover on junction box, and wires protruding out of the box (violation).

8. Unsecured NM cable dangling through mid-air (almost certainly a code violation). NM cable use in commercial installation may be a violation as well.

[This message has been edited by newsgraphics (edited 11-09-2005).]

wa2ise,

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Isn't there a rule against stringing romex thru the air like that?

Yeah, it's called lack of support. [Linked Image]

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My experience of metallic conduits, is that you never rely on any metallic conduits as part of the Fault Path.

Many times a properly installed metallic conduit system can provided a lower resistance ground path than the grounding conductor that would be installed inside it.

The NEC allows the use of many metallic raceways for grounding.

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250.118 Types of Equipment Grounding Conductors.

The equipment grounding conductor run with or enclosing the circuit conductors shall be one or more or a combination of the following:

(1)A copper, aluminum, or copper-clad aluminum conductor. This conductor shall be solid or stranded; insulated, covered, or bare; and in the form of a wire or a busbar of any shape.

(2)Rigid metal conduit.

(3)Intermediate metal conduit.

(4)Electrical metallic tubing.

(5)Flexible metal conduit where both the conduit and fittings are listed for grounding.

(6)Listed flexible metal conduit that is not listed for grounding, meeting all the following conditions:

a.The conduit is terminated in fittings listed for grounding.

b.The circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.

c.The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 1.8 m (6 ft).

d.The conduit is not installed for flexibility.

(7)Listed liquidtight flexible metal conduit meeting all the following conditions:

a.The conduit is terminated in fittings listed for grounding.

b.For metric designators 12 through 16 (trade sizes 3/8 through 1/2), the circuit conductors contained in the conduit are protected by overcurrent devices rated at 20 amperes or less.

c.For metric designators 21 through 35 (trade sizes 3/4 through 11/4), the circuit conductors contained in the conduit are protected by overcurrent devices rated not more than 60 amperes and there is no flexible metal conduit, flexible metallic tubing, or liquidtight flexible metal conduit in trade sizes metric designators 12 through 16 (trade sizes 3/8 through 1/2) in the grounding path.

d.The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 1.8 m (6 ft).

e.The conduit is not installed for flexibility.

(8)Flexible metallic tubing where the tubing is terminated in fittings listed for grounding and meeting the following conditions:

a.The circuit conductors contained in the tubing are protected by overcurrent devices rated at 20 amperes or less.

b.The combined length of flexible metal conduit and flexible metallic tubing and liquidtight flexible metal conduit in the same ground return path does not exceed 1.8 m (6 ft).

(9)Armor of Type AC cable as provided in 320.108.

(10)The copper sheath of mineral-insulated, metal-sheathed cable.

(11)Type MC cable where listed and identified for grounding in accordance with the following:

a.The combined metallic sheath and grounding conductor of interlocked metal tape–type MC cable

b.The metallic sheath or the combined metallic sheath and grounding conductors of the smooth or corrugated tube type MC cable

(12)Cable trays as permitted in 392.3(C) and 392.7

(13)Cablebus framework as permitted in 370.3.
(14) Other electrically continuous metal raceways and auxiliary gutters listed for grounding.

The key is proper installation.

Regardless if you use a copper conductor or steel tubing as the EGC the ground fault path is only as good as the installers terminations.

We have all seen copper grounding conductors loosely twisted together with no wire nut.

It all comes back to the skill or care of the installer.

Many times I pull a wire grounding conductor, many times I do not and I sleep well knowing I tighten my fittings and support the raceway so it can not move loosening the joints. [Linked Image]

By the way the work in the photo stinks. [Linked Image]

Bob

Bob,
We don't use metallic conduit at all here these days, it was popular here after WWII but with our Coastal air (read: corrosion) we gave it up for PVC.
But like anything, mate, you'll always come across it, if you work in older places.
Common Neutrals and all!. Ughhh!. [Linked Image]

Guys, I was kidding, perhaps I should have used emoticons to stress that point. The work is horrible, obviously the work of an untrained, negligent hack. Albeit, emt is used very often as the sole equipment grounding conductor, like it or not. It's compliant as Iwire already elaborately pointed out.

Hack job is too nice a word for this, @!#^%*
probably would be better but that is not a polite word to say.
BTW Newsgraphics, Welcome to ECN

EMT makes a fine grounding conductor, but not when the connector nut is missing (12 o'clock entry).

I don't no i see separated emt all over the place If you say it's a better conductor i believe it but some people like to use the pipe instead of a ladder or when pulling themselves onto machines.They loosen the fittings to the point that continuity is often totality lost.Ridged or threaded aluminum is a different story but i still run a wire.Inpectors like to see it and i find more EMT installations with grounding conductors than not.

Guys, you're not seeing the real danger here. This reporter guy IS ON TO US!!!! He actually read THE CODE BOOK!!!
More than I can say for some other posters. Ooops sorry, thats part of the secret too.

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I don't no i see separated EMT all over the place If you say it's a better conductor i believe it but some people like to use the pipe instead of a ladder or when pulling themselves onto machines.They loosen the fittings to the point that continuity is often totality lost.

Again it comes down to the installation, of course that can happen.

If you think it will be subject to that sort of damage IMO you should run it differently or install more supports or switch from EMT to IMC.

The addition of a copper grounding conductor does not mean we can then let all the fittings fall apart and that seems to be what you are saying.

Bob

I feel the NEC should 100% prohibit the use of EMT as a fault path in lieu of a dedicated grounding conductor. There are too many chances for the EMT's ground continuity to be broken, and it could become energized. A dedicated ground conductor would be connected to the conduit system at multiple points (pigtails at junction boxes connected to grounding screw, for example) and dramatically reduce the chance that ground continuity would be completely lost, even if a locknut became loose or was removed entirely.

Just as using interior water pipes as a ground path is unsafe because of the possibility they could become energized if ground continuity were lost, the code should also view EMT without a dedicated ground conductor in a similar light.

[This message has been edited by newsgraphics (edited 11-11-2005).]

I always pull a wire, I feel it's cheap insurance. But that's me. It adds up in bigger jobs and we all know that lots of times, the low bidder gets the job. It's very common around here to see raceways used as the sole egc.

I don't see 6" of wire coming into that box from any direction (especially from the right-hand side).

Run a separate EGC!

Many years ago I used to use EMT as the EGC. Unlike some folks I have had the misfortune to work with I was (and still am) always careful to tighten every connector and coupling. All that comes to naught when some inept remodeler (siders, roofers, whomever) decides to pop your straps and never puts them back. If you are using rigid or IMC you need not worry, but with EMT gravity will take its toll and you will no longer have a ground path. When this happens you will probably not be around to defend yourself or put it right. You probably won't even know about it.

For the last 8 years I have lived and worked in a jurisdiction where separate copper EGCs are required, but even if I had the option I would use a copper EGC. It's cheap insurance!

[This message has been edited by yaktx (edited 11-11-2005).]

iwire,
The point i was making was that these installations are the industry standard and code.You will only see ridged etc where it is required.Few machine tool builders or contractors will build better than the code which is the BARE MINIMUM accepted as they will price themselves out of the market(Economics).Of course it can and will happen thats why ground wires should be required buy code in EMT IMO.The quality of workmanship is another factor to add to the equation.I'm not putting anyone down just pointing out that the most important connection in any circuit should be as fool proof as possible.
And don't put words in my mouth.If a 180lb person steps on a piece of EMT how do you expect the one screw or compression rig in the fitting to hold it together.Do you honestly expect the millwright to come down off a machine and tell the sparky he broke it.I found your last comment to be extremely offensive iwire.Designed to p%ss me off in fact.
I can never know for sure the pipework i do today wont be destroyed by some clown over the next 30yrs that it may be in service.
The painted thread on the connector in the 12:00 position of the first picture shows the painter didn't care or even know the risk.

[This message has been edited by frank (edited 11-12-2005).]