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!
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.
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 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).]
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.
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.
By the way the work in the photo stinks.
Bob Badger Construction & Maintenance Electrician Massachusetts