Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
The primary raeson you see EMT is for the physical protection of exposed wiring. There is no particular safety issue between EMT and Romex residential or commercial wiring if it is concealed. Most commercial uses pipe, simply because changes are easier.
The NEC is far from discouraging the use of Romex. In fact they have actually expanded it’s use in buildings over 3 stories.
The IBEW in Chicago has a strangle hold on builders and government so they have these silly labor increasing rules to keep their employees busy.
The insanity doesn’t stop there. They wouldn’t even let the IBM guys lay interface cables between boxes IN the computer room.
The union had to do it.
New York City has now abandoned their “metal only” rule when they adopted the NEC.
Originally Posted By: Dan Leleika This post was automatically imported from our archived forum.
Yeah, over at Navy Pier and McCormick Place (these are convention centers) If you have a display booth you cant even plug a light into an electrical outlet…you have to call the Union guys…then they charge you.
Originally Posted By: bkelly2 This post was automatically imported from our archived forum.
I call out exposed romex in the living space here in Phoenix. Most often Kitchen Island outlets. Should be in conduit. I also call out exposed romex on the exterior of the house < 8’ high.
Originally Posted By: Joey D’Adamo This post was automatically imported from our archived forum.
wdecker wrote:
The one in question had 11 15 amps, 1 40 amp plus 6 20 amps. 325 amps or more than 3 times the penel rating. Doesn't that bother you?
It ISN'T 3 times the panel rating. The panel is 100A at 240 V which is 200 A at 120 V. Remmeber a "100A" panel has TWO legs at 100 Amps EACH...
So if you just added up 325A from all of the breakers, most of them are going to be 120V, and so it is not 3 times at all..
What you really need to do is figure out load at the same voltage... so add up all of the double pole breakers twice... and maybe you already did that (I'm not sure)... but then make sure you work it out either at 240V/100A or 120V/200A because that's what it really works out to.
Originally Posted By: mcyr This post was automatically imported from our archived forum.
Joey is right.
My own house has a 100 amp service and have breakers that add up to 310 amps. If you take that in account, and divide by 20 breakers it = 's 15.5 amps and divide that by two since you have two 110 legs in the panels, you are only drawing 7.75 amps, and that is if every circuit was being energized all at once which most likely will never happen.
I am sure the NEC describes it a lot more clearly.
Research on the NEC and reality would do you good. Common sense goes a long ways.
Originally Posted By: dbrown3 This post was automatically imported from our archived forum.
In North Central Missouri a code official once required conduit over romax in occupancies other than residential dwellings. Many reasons can determine the choice of romax or conduit. Local adopted Codes and/or by Code official having jurisdiction. At times these can contradict one another by interpretation of the code, as the code official determined that romax was only for residential use. Romax when used as specified by NEC, i.e. securely fastened, must be protected from physical damage, not installed in plenums… is determined to be safe. Residential dwellings incorporate romax, however if steel studs were used each opening through a metal member would need to be protected.
Common sense is important.
Commercial buildings can have romax, unless locality specifies conduit. This can be by adoption of only a portion of a particular code. So the local authority has jurisdiction.
Many times conduit in commercial buildings is used as specified by and earlier post-changing directions-conduit and junction boxes make it easier to branch in different directions. Also the electrician can make two circuits with only one ground and in three phase projects he can make three 20 amp circuits for receptacles with three #12 commons, one neutral #10 and one # 12 ground. The conduit and box also make it easier to branch from one light fixture to another, not to mention wiring emergency and exit lighting, although this is a practice that makes it hard to test emergency and exit lighting by switching the breaker to test battery back-up.
Also the code on number of breakers in a box does not state that you can have 44 breakers, it refers to the manufacturer of the service panel, which will be labeled with the maximum number. I should check NEC because I think that the limit is 40. Even with the 200 amp panel the most breakers that it will accept is 40 that is 30 full size and 10 that are 1/2 inch wide.
GFI's as stated might be grandfather in: in this situation I think that you all had a great idea to mention that the plugs were not GFI protected and note on the inspection that industry standards have changed. Recommend that a qualified electrician make the judgement. Note that a danger exists if appliances are used in these outlets.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
Until recently, New York City did not allow nonmetallic sheathed cable in residential buildings, so type AC cable and metal conduit was used.
I understand a big part of that (in addition to strong labor unions) related to concerns with rodents in basements eating through sheathed cables. With improvements to the health codes over the years it's just not as serious a concern any more, so sheathed cable in residential buildings is now allowed.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: cradan This post was automatically imported from our archived forum.
Quote:
In Illinois, the one 'defect' that is defined in the state HI law is 'significantly deficient', which is defined as 'an item, component or system that either does not function or poses a safety hazard.'
In a lot of rural AND suburban areas, Romex is almost exclusively used. I've personally seen MANY professional and apparently safe installations. I can't, don't and won't check with each and every AHJ regarding which code(s) and practices they may or may not have adopted, but my assumption would be (in certain areas, based on the sheer volume of Romex installed by professional local electricians) that it is acceptable, based on local requirements. Should you be operating in an area where this holds true, and decide you'll just call-out Romex cabling in general as unsafe without some specific evidence to the contrary, I think you're going to have some very, very unpleasant experiences in your future. You may find yourself defending your license...or paying for part or all of the re-wire for an entire residence.
Originally Posted By: bbadger This post was automatically imported from our archived forum.
jtedesco wrote:
Can someone give a cost comparison for the wiring of a typical one family dwelling in Romex or EMT?
What if I wanted to use Flexible Metal Conduit, "Greenfield of Flex?"
Joe, Don R claimed he say a study that the cost only added 2% to the electrical contract.  A $10,000 electric contract would move up to $10,200 Only $200 more for EMT over NM? 
I find that hard to believe, I think an add of 2% to the total building price is more believable. $100,000 build price would move up to $102,000
From my understanding the use of Flex is strictly limited also.
Tubing all the way.
-- Bob Badger
Electrical Construction & Maintenance
Moderator at ECN
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Thanks Bob:
I thought the cost was similar. I wired a house once in the San Diego area for a fellow Glendale, California building inspector who retired and I used 1/2" greenfield and the job went well.
When the combination inspector came into the building he almost  and said, "gee I never seen a home wired in flex, checked the service and gave the OK signing the rough on the card.
When I think about some of the shortcuts I took, I can remember running a few FMC's into the attic and into a 6" x 6' or 8" x 8" junction box extending the THHN/THWN circuits (with an EGC) to the rooms where necessary.
Boxes were all 4 Square and some even larger!
If I was to build a home, I would use a raceway such as greenfield, makes for a far more superior job that can be considered safer for sure!
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
If I really wanted a metal wiring method I would go for MC cable. The actual labor would be comparable with Romex but the material cost would be a bit higher.
Originally Posted By: Greg Fretwell This post was automatically imported from our archived forum.
I like to get experience with different wiring methods so I have just about everything in my house. I got started with MC when the Fl IAEI gave me their blessing for running it through the framing members of a screen room. Prior to that the only place I had used it was inside cabinets where I didn’t trust Romex. RNC is easy to work with and does a pretty good job underground but expansion and sagging makes it less than the best choice for exposed work. I used EMT for that. I don’t think people should ignore ENT as a compromize for NM where you want the ability to retrofit later. I used that in my bedroom renovation when my wife couldn’t make up her mind about where the switches go and what they control. I home runned all the boxes to a big carlon splice box in the attic. If we ever change our mind or move the furniture it will be easy to change. I also used ENT for all my low voltage runs.
I am also torture testing some on my boat and so far so good. It does appear to be a tough product. A decade in the Florida sun, salt water etc, didn’t seem to affect it at all.
Originally Posted By: roconnor This post was automatically imported from our archived forum.
, here are the permitted wiring methods for residences under the IRC Part VIII - Electrical (simplified version of the NEC) … compliments of www.iccsafe.org … note that local codes may vary
IRC TABLE E3701.4
a. Liquid-tight flexible nonmetallic conduit without integral reinforcement within the conduit wall shall not exceed 6 feet in length.
b. The grounded conductor shall be insulated except where used to supply other buildings on the same premises. Type USE cable shall not be used inside buildings.
c. The grounded conductor shall be insulated.
d. Conductors shall be a type approved for wet locations and the installation shall prevent water from entering other raceways.
e. Shall be listed as "Sunlight Resistant."
f. Metal raceways shall be protected from corrosion and approved for the application.
g. RNC shall be Schedule 80.
h. Shall be listed as "Sunlight Resistant" where exposed to the direct rays of the sun.
i. Conduit shall not exceed 6 feet in length.
-- Robert O'Connor, PE
Eagle Engineering ?
Eagle Eye Inspections ?
NACHI Education Committee
I am absolutely amazed sometimes by how much thought goes into doing things wrong
Originally Posted By: tray This post was automatically imported from our archived forum.
I have inspected new construction in Kankakee county and found Romex, the job was done professionally. Also in the Eastern part of Will county, Romex is still being used.
