Hey Electricians... Can you help by proofing this new course?

http://education.nachi.org/show.php?course_id=53

Post corrections and comments here please.

Course developed by member Russ Meyers. Thanks Russ!

All contributors will be recognized on the last page of the course. Please help.

Could you make it available with out all that resigning up?

I signed up but I still can’t get to anything

Can’t get past the first page on anything there. Have tried several times and just can’t get there.

Would be glad to help but I just can’t seem to figure out how to see it :mad:

Have been working for more time than it would take to take the test just trying to see it :mad:

Would be glad to take a look but there don’t seem to be a way for me to access it :mad:

Have I made my point clear that I can’t see it? :twisted:

I don’t think that I would pay a fee just to help someone on a problem but if you can make it possible for me to see it I will gladly make my comments good and bad

Hi Mike,

as a non-member you cannot access beyond the first page

Regards

Gerry

I was and still very eager to help Nick out but I just can’t get there. I think it is asking a bit much to ask someone to take a test and pay a due fee just to be able to help but then again who am I?

I will be glad to add my two cents and share my knowledge with the Home Inspectors as long as it doesn’t cost me anything.

Being that I only work part time and the banks are failing my income is very limited and I am starving to death. I have taken to eating road kill in order to survive and not die from starvation.

The last time I counted my life savings it took me almost an hour to count my money. I put the pennies in one pile and the nickels in another, didn’t have any dimes and quarters as I had already used all of them to pay the light bill.

I have taken to driving my car down hill all the time as I can’t afford to buy gas for it. The wife is getting tired of pushing back up the hill for our next trip???

Seriously, I would be glad to proof it item in question as long as I don’t have to pay an annual due in order to do so. Is that asking too much?

I thought we already had one done by Gerry a long time ago and I assisted him on it.

Statement made in the presentation:

Armored cable must be supported by a strap or staple every 6 feet and within 24 inches of every switch or junction box, except for concealed runs in old work where it is impossible to mount straps.

Corrections you need to make :

**(B) Securing. **
Unless otherwise provided, Type AC cable
shall be secured within 300 mm (12 in.) of every outlet
box, junction box, cabinet, or fitting and at intervals not

exceeding 1.4 m (**4 ****1/2 **ft) where installed on or across framing
members.
**© Supporting. **

Unless otherwise provided, Type AC cable
shall be supported at intervals not exceeding 1.4 m (41.2 ft).
Horizontal runs of Type AC cable installed in wooden

or metal framing members or similar supporting means
shall be considered supported where such support does not
exceed 1.4-m (41.2-ft) intervals.

Note : MC Cable is the cable allowed to be supported very 6’

**[FONT=Times-Bold]size=2 Securing. **[/FONT][/size]
[FONT=Times-Roman][size=2]Unless otherwise provided, cables shall be secured[/FONT][/size]
[size=2][FONT=Times-Roman]at intervals not exceeding 1.8 m (6 ft). Cables containing
four or fewer conductors sized no larger than 10 AWG

shall be secured within 300 mm (12 in.) of every box, cabinet,
fitting, or other cable termination.

**© Supporting. **
Unless otherwise provided, cables shall
be supported at intervals not exceeding 1.8-m (6-ft)
Horizontal runs of Type MC cable installed in wooden

or metal framing members or similar supporting means
shall be considered supported and secured where such support

does not exceed 1.8-m (6-ft) intervals.

On the part with Ekectric Circuits…it might be better serves to explain it a little differently…

“Section 220-3b of the code requires two small appliance circuits to serve only appliance outlets in the kitchen, laundry, pantry, family room, dining room, and breakfast room. Both circuits must be extended to the kitchen and serve the counter top areas; either one or both of these circuits may serve the other rooms. No lighting outlets may be connected to these circuits, and they must be wired with 12-gauge wire and protected by a 20-ampere over-current device. Each circuit will have a capacity of 20 x 115 (2,300 watts). This is not too much when you consider that toasters often require more than 1,600 watts.”

My suggestions are in RED, and your other info gets the point accross…again it is not for electricians who should already know this info so it is good to keep it brief and to the point.

Under the grounded outlet statement it reads:

If the conventional two-opening outlet is used, it may be grounded if the screw that holds the outlet cover plate is electrically connected to the third-wire ground. The tester should light when one lead is in contact with a clean paint-free metal outlet cover plate screw and the hot side of the outlet. If the tester does not light, the outlet is not grounded. If a two-opening outlet is grounded, it may be adapted for use by a three-wire appliance by using an adapter. The loose-wire portion or screw tab of the adapter should be secured behind the metal screw of the outlet plate cover. Many appliances, such as electric shavers and some new hand tools, are double insulated and are safe without having a third ground wire.

Green Comments : If the receptalce is a 2 wire system chances are the center screw that holds the cover is not going to be grounded…be careful someone does not do a bootleg to fool you on this…I am not sure I would actually make that statement…
Blue: The adapters with the wire form them are not approved anymore

I will give more suggestions, I just sold my Bike and I have to run to DMV with the guy…have fun guys

[/FONT][/size]

Thanks Paul!

Paul, I think you might be correct on that.

I just took this exam again and feel I have taken it 3 times.

Remember, I am a Carpenter by trade and know enough about electrical to be dangerous. ha. ha.

Anyways, I got a 91 this time.

It is unfortunate that we do not get to see which ones we got wrong.

Same mistakes probably happen again and again because of that.

Few questions popped up while taking the exam.

Since when are the amount of 15 amp circuits determined or related to square footage.
I have always been told that a 15 amp circuit had 8 receptacles max. and 20amp circuit could have 11.
Paul, could you elaborate on this?

I also notice armored cable was called BX.

Wasn’t that the original armored cable that we use to use that was also called Greenfield.?
I thought in today’s world it was called MC. Correct me please.

Hot wires are never white was stated.

Am I wrong in my thinking that sometimes it could be and painted black.

Now these are items I notice in the Field of Construction, so any interpetation of the right way or how it should be would be helpful to me.

Paul, thanks for reviewing this with all of us.

I am sure we will all learn something out of this whole thing.

Your contributions are very well appreciated.

Thank you.

Marcel

Got this in an email from a student, “Mike why are you being so rude to Nick as he was only asking for help”

If this student though that I was being rude to Nick there is probably several others out there that think the same way so I feel as though I should address this now before it gets out of hand.

It was my full intention to be funny. Yes I agree that I do have a sick sense of humor as can been seen here.

I also thought that this would put a grin on someone face as we all know no one is going to pay a utility bill using dimes and quarters unless they use a wheelbarrow to roll them in with.

So please, should anyone find my post offensive just try and look at the one making the post. I promise I was only trying to be funny.

Marcel,

Here is your question :

Since when are the amount of 15 amp circuits determined or related to square footage.
I have always been told that a 15 amp circuit had 8 receptacles max. and 20amp circuit could have 11.
Paul, could you elaborate on this?

My Answer: Nothing in the NEC actually tells us how many receptacles we can place on a circuit as it applies to residential applications. We do have statements that direct us to evenly proportions of branch circuit layouts and so on but dirrectly we do not. Many people confuse the 90vA per receptacle required on commerical calculatiosn for receptacles but it does not really apply to residential applications.

Now what you have to look at is this…how many luminaires are you also putting on the circuit along with those receptacles…would be poor design if you had say 12-13 amps of known lighting loads on a circuit and then put a crude load of receptacles on it also…so it is all a design thing but again the NEC does not tell us how many per circuit in residential applications…but common sense does.

Your other question was :

Wasn’t that the original armored cable that we use to use that was also called Greenfield.?
I thought in today’s world it was called MC. Correct me please.

Ok…we have both MC and AC in todays world…as well as MCAP as well as Hospital Grade MC…and so on.

MC Cable has a Equipment Ground ran with the conductors and AC Cable uses the outer case as the equipment ground so to speak…because AC has convelutions that connect each spiral portion of the cable providing that low impedance path required to aid in opening an overcurrent protection device ( OCPD )

BX is a tradename only…it is not a wiring method per se’ meaning it is refered to as AC or MC these days, it is very common for people to think the old BX 's outer jacket is approved as a fault current path of low impedance and I disagree…look at its metal makeup, look at its poor connection properties and its impedance is not the same as the AC Cable used today…so I tell people…if you think BX ( tradename of old metal spiral cable ) and its metal outer jacket is a good fault current path…how come they wont let MC be used the same way in todays world without the equipment ground being run inside…AC and MC are not created equal.

Gotta run…guy is waiting for me…later everyone.

Paul, thanks for the clarification on that, it was very valuable information.

Thank you

Marcel :):smiley:

If I remember correctly “Greenfield” was once (is?) a brand name that is often used generically to describe flexible aluminum conduit.

Sorry…I missed that one…Yes, Greenfield is more a flexible metallic conduit that wires are installed into…but not generally with the wires already within it.

I am sure somewhere it may exist…but my experience with “greenfield” was that I had to pull the conductors within it…

Here is some Greenfield for ya…:wink:

greenfield.jpg

Thanks Paul, and I found this that helps my understanding and might help others as well;

WHAT’S THE STORY?

http://www.seatekco.com/images/bx-02cw.jpg

Today’s BX and MC cable vs vintage BX Cable

Armored Cable Today:
Safe, Reliable, and Economical

by George W. Flach, Electrical Consultant, New Orleans, LA

Prevailing misconceptions about the present-day armored cable most likely stem from imperfections inherent in the original BX. Improvements made in the product are readily apparent when today’s armored cable (right) is shown side-by-side with the old BX.
Today’s armored cable, historically known as BX and more correctly as Type AC, has proved to be a safe, reliable, and economical wiring method. However, there continue to be restrictions, and sometimes prohibitions, on its use in many areas. What is behind such restrictions and are they warranted?
These restrictions on the use of armored cable, for the most part, are the result of years of misconceptions. Today, many electrical inspectors are reconsidering their position on armored cable because of its long safety record, NEC recognition, and improvements made since its introduction.
Basic armored cable was developed in the early 1900s by Edwin Greenfield and Gus Johnson, who called their product BX cable. It has become a generic term for all armored cable. Some of the prevailing attitudes about the product most likely stem from imperfections inherent in the original BX.
For instance, the Type R rubber insulation used was subject to thermal-aging and cracking. The cotton-braided covering on conductors and overall braided or paper covering did little to prevent moisture damage to the insulation. When the bonding wire was finally added, it was flat and subject to breakage. In addition, it (and even the armor itself) was often mistakenly used as the neutral conductor.
The biggest problem was the lack of proper cutting tools. Old cutting methods, such as hacksaws or pliers for crimp cutting or twisting and breaking the steel armor, were very unsatisfactory and often led to nicks on the insulation and conductors, creating circuit opens or shorts.
As a result of these past deficiencies, the excellent safety record of armored cable attested to by decades of NEC recognition has been ignored. Improvements including newer, safer materials and expanded, application-oriented products, too often have gone unnoticed. The progress in the performance of armored cable is a direct result of changes made in its construction and installation techniques.

http://www.seatekco.com/images/RS-101A-4C2.jpg

  • Insulation: The early rubber insulation has been replaced by thermoplastic insulation with excellent aging properties, thermal characteristics, and dielectric strength.
  • Wraps: Cotton braiding has been replaced with impregnated paper material that has good dielectric qualities and is moisture-resistant.
  • Anti-short bushings: Fibrous material used in early bushings has been replaced by thermoplastics that allow easy sliding and eliminate ripping, tearing, and deterioration.
  • Bonding wire: Easily breakable, flat bonding wire has been eliminated and replaced with a bonding wire that is in constant contact with the armor throughout the cable length.
  • Galvanizing: The early practice of galvanizing the sheet steel first, then cutting it into strips, left the cut edges unprotected and allowed them to rust. This technique has been di-opped in favor of galvanizing the steel after cutting, providing superior corrosion resistance.
  • *Cutting techniques:*A handheld roto-cutter (Seatek Co. Inc. pioneered the first commercially successful BX armor cable cutter in 1973. This patented tool is known as the Roto-Split](http://www.seatekco.com/rs-101a.htm))
    is now available to use in lieu of hacksaws, pliers, etc., for fast, automatically controlled cuts that significantly reduce the possibility of conductor damage.

http://www.seatekco.com/images/rs-101-1c.jpg

In addition to these changes, armored cable is available now in various sizes and with multiple conductors for a variety of specialized applications, including modular wiring and fire-alarm circuitry.

Electrical inspectors in many areas of the country with strict building codes have recently begun to allow armored cable for a variety of applications when as little as two years ago some were not. Individuals such as Leo F. Martin, Deputy Commissioner for the City of Boston; Robert C. Duncan, Deputy Manager of Building and Safety for the Reedy Creek Improvement District and chairman of the Florida Chapter of the International Association of Electrical Inspectors (IAEI); and James G. Stallcup, Chief Electrical Inspector for the City of Fort Worth, TX, have rethought their positions.
Armored cable, today, is a proven and tested product with an exceptional safety record, duly recognized by the NEC and listed by independent testing laboratories. It’s an option that electrical contractors find has many advantages.
What’s the Story addresses electrical design, construction, maintenance, and equipment questions and problems. Contributed articles will be considered; comments on published articles are encouraged. Write What’s the Story, EC&M, 1221 Avenue of the Americas, New York, NY 10020.

REPRINTED FROM AUGUST, 1986 ISSUE

*ELECTRICAL CONSTRUCTION AND MAINTENANCE *

@ Copyright 1986 McGraw-Hill, Inc. - All rights reserved.

http://www.seatekco.com/images/bx-03cw.jpg

**VP of Product Development for AFC Cable Systems, the term “BX” stands for “Product “B” - Experimental.”

Apparently, back when the product was first developed, the first manufacturer of this product had only one product at the time: “Product “A””. So when they developed this product they didn’t know what to call it. Somebody suggested "Product “B” with the suffix “X” added as the product was at that time experimental.**

Well, learned a little bit more today on this subject. :slight_smile:

Marcel :D:)

Armored cable (type MC) has been widely used industrial applications for many years in place of conduit and wire. There are various constructions, but in most cases there is a compelete cable assembly over which an armor of aluminum or steel is applied. The armor can either be a continuous corrugated ‘tube’ (CLX) or a more flexible version the has strips of metal rolled into corrugations. In many cases, an outside PVC jacket is also applied which is color-coded to signify the voltage level (typically black for 600V, yellow for 5KV and red for 15KV). Here’s a picture:

sheet9-150.gif

Mike:

Look here for the original version of this tried and true material already “in the public domain”.

http://www.cdc.gov/nceh/publications/books/housing/cha11.htm

And for the rest of the story look here:

To order hard copies or CD-ROMs of the complete manual,
call 1-800-CDC-INFO.

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.12.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.13.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.14.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.15.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.16.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.17.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.18.jpg

http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.19.jpg

](http://www.cdc.gov/nceh/publications/books/housing/Graphics/chapter_11/Figure11.13.jpg)

Being that the Home Inspector is looking at buildings that were built through many decades it might be worthy to know a little history about the flexible cable with a metal covering.

Today we have two basic types of factory assembled cables and one raceway that closely resemble these. The flexible metal raceway or Greenfield as it is sometimes called is not a cable assemble so I will finish about this here.

Today we have the cables as described by Paul above.

One decade ago in the early 90s, the 1990 cycle to be exact, verbiage was added to the NEC that made it clear that MC cable was to contain an equipment grounding conductor [section 334-23] There was no mention of the EGC in the 1987 edition. The only requirement for equipment grounding was also found in 334-23 but it was worded differently, “334-23 Grounding. Type MC cable shall provide an adequate path for equipment grounding as required by Article 250.”

Verbiage found in 333-4 for type AC cable of the 1990 cycle simply stated that there shall be an internal bonding strip to intimate contact with the armor for its entire length. This is the EGC we see in today’s cable.
This verbiage concerning AC cable is unchanged from as far back as the 1962 cycle although it was found in 334-4(b). In this code cycle there is only one section titled Metal Clad Cable which covered both AC and MC.
In the 1956 cycle both was referred to as Armored Cable and was covered under 3341 and get this, it was on page 84.

This conjoining of the two (AC & MC) took place somewhere between the 1975 cycle and the 1984 cycle. I don’t have a ’78 or ’81 cycle to nail it down a little closer.
In the 1975 cycle 334-4(a) did require that type MC provide a path for grounding purposes but did not reference Article 250

I feel that this knowledge would be prudent to the Home Inspector so he now has the knowledge that until 1990 MC wasn’t required to contain any type of equipment grounding conductor but was only required to provide a grounding path as required by 250 and as little as 30 years ago didn’t even make a reference to Article 250.

As the Home Inspector goes about their duties they should understand that the standard of practice by both electricians and electrical inspectors from each time period changes.

What we are looking at sometime is not what we are seeing.

As a Home Inspector looking at a home twenty years or older unless I could visibly see an equipment grounding conductor I would not assume that the armor of any cable was the equipment grounding path. I would not trust the reading of most meters that showed a grounding path either. If a meter is reading the continuity of the armor of a cable it should also be showing the impedance of that path. The armor might have too much impedance to carry fault current but still trip out a GFCI device. Never trust the armor of a cable to be able to carry the same current as the conductors contained there in.

As Paul has pointed out above the armor of what some called “BX” will not carry the current of a fault therefore should always be called out. I also hope I have given the HI fuel for any debate they might have with any electrical contractor that might dispute them.