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Master Brian
01-26-2009, 08:59 AM
Maybe there isn't an easy answer to this question, but what are the main things that cause an electrical fire?

Reason, I ask is that I am going through my house, which was a bank repo, and cleaning up a lot of old wiring. There are a few metal boxes in walls that move around, when you plug stuff in. They have come loose from the lathe and plaster. I have several areas where fixtures where removed and wires just hanging inside boxes with no covers, and metal boxes in basement ceiling that have several connections. I have come across several of these boxes that only have tape covering the twisted connections and on some the wires are so brittle that when you move them, the insulation crumples.

There is a bit of knob and Tube, I'm not overtly concerned with that, except for portions that are burried under insulation as I read that is a no-no, UNLESS an electrician says it's ok.

I have a lot of that BX(?), the stuff in a metal conduit, and old silverish/black romex and some that looks like black romex. The house was built in 1915, so if the wire has been made, it's likely in my house.

While repairing one outlet last night, I came accross one spot where when a coax cable was run, they actually knicked the romex(?) wire and you can see bare wire on both the hot and neutral wires and they WERE (I took it out) right nex to a joist!

Right after buying the house, my wife was doing a load of laundry and the breaker kept tripping and you could smell burnt wire. I called my electrician, whom was slated to upgrade me from 60amp to 200amp service, and had him come out. He found a wire that had crossed, due to age deteriation, and shorted out. This was the clothes dryer, I might mention...

In any case, I'm sure you can see my curiousity over what I should look for. I have replaced several runs and even removed lines that didn't go anywhere any longer. I feel very competant in working with elecricity in this manner, but I am curious, what is the major cause. I can't believe some of these old connections haven't failed yet.

I am also concerned when an inspection is required and when it isn't. I am planning on calling the inspection unit and speaking with them as well, but to be honest, I find some of these areas, I've mentioned and I yank them as soon as I find them. Not tanking any chances....

Master Brian
01-26-2009, 09:01 AM
I should probably mention, I fully realize the boxes with hanging wires, should be closed up with a cover. In some cases, I plan on that. In some, I'm afraid moving the wire will crack the insulation, so I'm leaving as is, until I can get to that circuit.

Scuba_Dave
01-26-2009, 10:42 AM
My understanding here is that an electric permit is almost always needed. The (possible) exceptions being when you are replacing a device - ceiling lamp, fan etc. If I'm running wire I need a permit. The problem I have run into is that they expire 6 months after issued, the building permit does not expire (per my Dept) so long as work continues.

A loose wire can cause an arc, then a fire

Insulation cracking & falling off could cause a short/spark

Smaller gauge wire on a larger breaker could cause a fire
IE - lamp cord or 14g on a 20a circuit with a heavy load

That's what I can think of

drick
01-26-2009, 02:29 PM
The number one cause of electrical fires is loose connections. Loose connections generate heat, which causes a fire. Even in new construction I saw a case where homeowner installed a dimmer but didn't securely fasten the wire nuts. One was making a weak connection and caused a small fire. Luckily the homeowner was home, smelled it and put out the fire before is spread into the wall. No major damage but it was a PITA to replace all the wiring to that box.

In another fire it was the knob and tube poorly connected to an outlet. The outlet had a space heater plugged into it. It looked like the conductor to the back of the outlet had broken off due to movement/age but was still just barly making contact to the screw terminal on the outlet. This was a more serious fire causing about $50K in damage.

The knob and tube I've seen has been in relatively decent condition. The only problem being that 4 to 5 rooms would end up on a single circuit. If you are planning on keeping the knob and tube I would put arc fault breakers on those circuits to be safe.

If you are planning on doing extensive rewiring take the time to read the portion of the NEC dealing with residential wiring. It covers outlet spacing, kitchen and bath circuits, etc.

-rick

Scuba_Dave
01-26-2009, 03:35 PM
We also had neighbors house that partially burned - Fire Dept said it was a due to a radio that was plugged in. I don't remember if it was on or off.
Their fire was contained mostly to one bedroom. This was due to the fact that it was a solid wood door, and that they always closed their bedroom doors
I have hollow doors at this house & will be replacing them with solid wood

Billy_Bob
01-26-2009, 06:24 PM
I don't think there will be an electrical fire at your house! You are doing all the right things and are on the right track.

You are learning, asking questions, learning about permits, hiring an electrician when needed, and snooping around your house examining/fixing things.

Good thing to have covers over boxes, but also I think it is a good idea to not move the old wires until you can replace them (especially if insulation crumbling).

I would say to check the size of the fuses/breakers and that they are correct for the wiring, but the electrician will do that when upgrading your service.

Insulation crumbles a lot in old light fixtures due to the heat there. Might not want to even peek at these until you are ready to replace the wiring.

Might want to get a book or two on electrical wiring here...
http://www.buildersbook.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=bbi&Category_Code=40

iminaquagmire
01-26-2009, 07:28 PM
Overloaded circuits and loose connections are the biggest issues. I was just on a fire call (I'm on the local department) where the leading opinion so far is that the space heater overloaded the circuit. Good advice stated so far. The suggestion for arc fault breakers on the old circuits is a good one.

GabeS
01-26-2009, 07:56 PM
If you have the budget for it, just rewire the entire house. It sure sounds like you need it. Too many different kinds of wiring. That means a lot of different people worked on that wiring in the house and chances are some were not licensed. Too many possibilities for something done wrong. If you are getting a new service then run all new circuits.

Did you check for aluminum wiring?

A good electrician could rewire the entire house without creating too much damage. Then just patch everything up after the electrician is done.

jar546
01-27-2009, 07:01 AM
Here is a link that will give you facts

http://www.nfpa.org/index.asp?cookie%5Ftest=1

Master Brian
01-27-2009, 08:51 AM
Thanks for all of the feedback. My goal is to have completely new wiring in the house. The service panel has already been upgraded and I had them install sub panels in my garage and my basement.

I am hoping to be able to do the rest myself and I plan to get everything inspected when I'm done, just so it never becomes an issue down the road.

Is there somewhere I can pick up a copy of the NEC dealing with residentual wiring? I know the library should have a copy, just hoping there is something online, I can download. The other question is, how hard is that for the average joe to understand? I understand most all of the basics and am learning more each day.

One question I do have is regarding the Arch Fault Breakers. It seems some people really like them, but most of the local people I speak with say to stay away, the technology isn't very good yet. With that said, I know it is code that the bedrooms have them, so I'm pretty sure I'll need them for my re-wire to be within code. I am just curious why I hear bad things about them.

Also, can someone clearify this...I understand the Arch Faults to be needed on the outlet circuit for the bedrooms, but what if all the lights are on a seperate circuit, do I need one for them as well?

jadnashua
01-27-2009, 09:33 AM
Rumor has it that the original versions of arc-fault breakers weren't all that great...the newer ones are supposed to be better (fewer false or nusiance tripping). I think someone said that future codes may require them nearly everywhere in residential situations. Could get ugly.

Scuba_Dave
01-27-2009, 09:42 AM
2008 online:

http://nfpaweb3.gvpi.net/rrserver/browser?title=/NFPASTD/7008SB

Yes, Arc faults will be required in a LOT more places as will the Tamper proof receptacles & outside must be TP & weather resistant. I've checked & the costs on these new outlets are very high right now

Square D had a recall 2 years ago (I think?) on some of their Arc fault breakers - I think they had blue buttons & now switched to green buttons. I do not think all blue button Arc faults were effected - check the link

Yup:

First, confirm the date that a Square D load center or Combination Service Entrance Device (CSED) was installed in your home. If it was installed before March 1, 2004, you will NOT need to have your Square D arc fault circuit breakers inspected or replaced. Next, check your load center or CSED for arc fault circuit breakers. This is the device that distributes electricity to the various circuits in your home. Be sure that it is a Square D brand device. A Square D brand device will have the Square D logo (Figure 1) embossed in the front cover. You can easily locate an arc fault circuit breaker by opening the front cover and looking for the blue “push-to-test” buttons (Figure 2).
http://www.us.squared.com/us/squared/corporate_info.nsf/unid/9CB09A222974952E85256F19005EAE4F/$file/howcanIknow.htm

Thatguy
01-27-2009, 10:26 AM
High temp. causes fires when in contact with combustible material.
http://www.tcforensic.com.au/docs/article10.ht
If heat loss to the surroundings is < heat gain from power in, the temp. goes up until these two are equal.

10w dissipated in something with the surface area of a wirenut is too hot to touch. The same power dissipated in something with a surface area the size of a watermelon, or a panel busbar, is hardly noticeable.

GabeS
01-27-2009, 10:57 AM
I think they are requiring AFCI on ALL circuits that don't have GFCI. Wait for a pro to clarify, but we had this discussion in prior posts. You could probably do a search and pull those posts up. I think they costs $40 each or around there.

Master Brian
01-27-2009, 01:19 PM
I think they are requiring AFCI on ALL circuits that don't have GFCI. Wait for a pro to clarify, but we had this discussion in prior posts. You could probably do a search and pull those posts up. I think they costs $40 each or around there.


I think $40 is about where they were when I looked into them one other time, but like I said, I was told by several, even an electrician, not to mess with it if I didn't need to.

From my city's website, it looks like just bedroom circuits, I just couldn't tell if they were needed for the lights, if on an independet circuit. Hmm... I guess the inspector can tell me and too be honest, this isn't something that should be hard to retrofit....

Master Brian
01-27-2009, 01:52 PM
Suba Dave, thanks for the link. Does that whole thing deal with residentual? I am glancing through it and it is a bit overwhelming. Most of that is stuff that I would never get into. It also looks like they do want Arch Faults in many other places besides the bedrooms, but the city's website doesn't say that. Maybe their code isn't there yet. Hmm....

Anyone take one of these homeowner tests? I am really curious how difficult it is.

Also, will they actually make me install a receptacle for the 6' rule on any wall space? Some rooms such as the bedrooms, I am working on making openings. However, my dining room already has wallpaper and I do not want it messed up. There are receptacles, just not per code. I didn't install them either. Remember this is a 1915 house.

jar546
01-27-2009, 02:28 PM
The NEC has been in existence for over one hundred years and uses technical language, not layman's terms. This eliminates confusion.

It is not easy to read and not the easiest to understand unless you already have a firm grasp on the fundamentals of electricity and electrical work. The NEC is not a DIY manual. There are lots of books out there that are sold soley for the purpose of explaining parts of the NEC.

Almost every single chapter and section of the book has to do with residential in one way or another. You can probabl skep the 500 series section and some of the 700 section but you will find information that you need in every single part.

Here is an example:

A simple item like bonding or grounding the main panel is covered by multiple sections such as 250.50, 250.50(A), 250.52(A)(1), 250.66, 250.53, 250.53(A) & (D)(2), (E)(G)(F) and even more depending on other sections.

Master Brian
01-27-2009, 02:39 PM
I understand it isn't meant to be easy for a layman.

I guess I am curious as to the test. The inspector didn't give me much info, just said, I can look at a copy of the NEC, there or at the library. Supposedly the homeowner test only covers the sections that pertain to residential, but like you say, every section seems to have residential stuff.

I can't however believe the stuff on bonding would be in there, as the homeowner isn't allowed to do the panel. *there being the test.

I do wonder how hard 25 questions in open book format with a 3hr time limit could be, but I have taken many 25 question tests in my field that easily take me 1 hour in open book format. So i'm willing to bet anything goes and I wonder how excited they are to actually have a homeowner pass the test. That is the Million Dollar Question!

I guess the only way to be sure is to take the test. Right now I am trying to draw up my plans and then I'll progress from there.

jar546
01-27-2009, 07:44 PM
Here is an easy electrical question that a homeowner should know how to figure out as junction boxes are always being tapped into or installed. I recently came upon this situation while conducting a code inspection.

This may help to prime you for the test.

Basement, junction box. Metal 4" x 4" x 2-1/8" deep with cover and ground screw properly placed. No devices, internal clamps, plaster or extension rings on or in the box. Just wires and wire nuts except for the compression sleeve on the equipment grounds.

There were eight (8) 12/2 NMB cables entering the box.

Questions:

1) Is the box properly sized?

2) What is the box fill?

3) What size box needed?

PeteD
01-27-2009, 09:17 PM
I can't resist taking a stab.

There were eight (8) 12/2 NMB cables entering the box.

Questions:

1) Is the box properly sized?
NO

2) What is the box fill?
17

3) What size box needed?
38.25 cu in - not sure of the standard size

Not an electrician so don't shoot me if I am wrong.

Billy_Bob
01-28-2009, 09:25 AM
If you're going to get the NEC, Might want to get the NEC handbook which also has pictures and examples. Can get that here...
http://www.nfpa.org/catalog/product.asp?pid=70HB08&order_src=A291&cookie%5Ftest=1

And use that along with a residential wiring book which says it uses the 2008 NEC.

As to Arc Fault breakers, basically the 2008 says every room but those with GFCI. HOWEVER my state (Oregon) has modified the 2008 to be bedroom only. Also my state has exceptions for new GFCI rules.

Many people are having trouble with vacuum cleaners and a few other appliances tripping arc fault breakers. I would advise only installing Arc Fault breakers where required due to these problems.

Then other states are going by 2005 NEC rules or older. I think one island on Hawaii still goes by 1993 rules!

Anyway what is required is a local thing. The rules can even be different within a state (city different from rural), so find out what is required for your specific area and where you can get a copy of you areas modifications to the rules (if any).

This shows how different various states are with the NEC rules...
(The final word on this is your local inspector, not this map!)
http://www.nema.org/stds/fieldreps/NECadoption/implement.cfm

Master Brian
01-28-2009, 09:46 AM
This may help to prime you for the test.

Basement, junction box. Metal 4" x 4" x 2-1/8" deep with cover and ground screw properly placed. No devices, internal clamps, plaster or extension rings on or in the box. Just wires and wire nuts except for the compression sleeve on the equipment grounds.

There were eight (8) 12/2 NMB cables entering the box.

Questions:

1) Is the box properly sized?

2) What is the box fill?

3) What size box needed?

I'll start by giving my answer based off what I would do. I would say it is overfilled and I wouldn't put more than 4-5 wires max in that box. 4 is probably the most I would use and it would be a square box. I wouldn't know the fill and if I had the scenerio in front of me, I'd go by looks. I know that is not the "Correct" answer, but it should be safe.

Now if I were taking the test and having a posted 2008 NEC in front of me, here is my answer...

Is this a round box or a square box?

1) A 4x4x2-1/8 metal box (Round houses 9 conductors) (Square houses 13 conductors). So NO on both counts.

2) 18. The black and white wires account for 16, the ground wires account for 1. I am also adding 1 for the grounding clamp per 314.15(B)(2) of the NEC dealing with Clamp Fill states internal clamps should account for 1.

3) 4-11/16 x 2-1/8 square

220/221
01-28-2009, 03:18 PM
what are the main things that cause an electrical fire?

There is only one thing that causes fire. Heat.

Heat usually comes from poor connection/terminations/splices.

Copper conducts electricity well. A loose connection builds up carbon where the electricity is jumping a gap. Carbon doesn't conduct well and the connection gets progressivly worse. In the right conditions the connection can get hot enough and act like a heating element to start a fire.

Master Brian
01-29-2009, 10:07 AM
No response on the "Test"?

GabeS
01-29-2009, 11:12 AM
No way you can put 8 cables in a skinny 4x4. This is just from common sense perspective and not code perspective.

A thick 4x4 would fit them, but it would be tight. And why in the world would you have 8 cables in a junction box anyway?

You would need a larger box than 4x4. I don't know what "fill" is.

Master Brian
01-29-2009, 11:55 AM
No way you can put 8 cables in a skinny 4x4. This is just from common sense perspective and not code perspective.

A thick 4x4 would fit them, but it would be tight. And why in the world would you have 8 cables in a junction box anyway?

You would need a larger box than 4x4. I don't know what "fill" is.

I don't think of the 4x4 box mentioned in code as being "skinny", but I agree, I'd never put that many in either. May be deemed "safe" via code, but too hard to mess with in my opinion.

Fill, is referred to as the number of conductors. a 12/2 wire has 2 conductors + the ground. My understanding is all the grounds only count as 1 conductor, but I could be wrong. I didn't know what it was either until I looked through the NEC....

Scuba_Dave
01-29-2009, 12:31 PM
Well with a 4x4 you could have 2 circuits or more
2 in, 2 out to the next box
Some people put a single gang triple switch - that's 3 wires to the devices. Say even 2 single gang double switches - that's 4 wires
I'd never do it, but I'm sure someone somewhere has

PeteD
01-29-2009, 03:54 PM
Well with a 4x4 you could have 2 circuits or more
2 in, 2 out to the next box
Some people put a single gang triple switch - that's 3 wires to the devices. Say even 2 single gang double switches - that's 4 wires
I'd never do it, but I'm sure someone somewhere has

The wires don't really add up that quickly for combination switches, because you can run 3 wire cable. A deep 22.5 inch single gang box can handle a quad switch. One 14/2 coming in (2), two 14/3 going out (6), ground for all (1), and (2) for the switch. Total fill is 11, which works for 14 gauge (2 cu in per) with 0.5 inches to spare.

Pete

Scuba_Dave
01-29-2009, 04:50 PM
The wires don't really add up that quickly for combination switches, because you can run 3 wire cable. A deep 22.5 inch single gang box can handle a quad switch. One 14/2 coming in (2), two 14/3 going out (6), ground for all (1), and (2) for the switch. Total fill is 11, which works for 14 gauge (2 cu in per) with 0.5 inches to spare.

Pete

Not if the lights are not in the same area
No reason to run 14-3 to an outside light, then to an overhead light, then to another light in another room, then to a light in a bathroom, then to another outside light on the other side of the house
And not if the runs are 12-2, which is what the "test" referred to
And yes I have seen that many switches in 1 place, but they used a 4 gang box for more room

hj
01-29-2009, 05:04 PM
HOW does a circuit get overloaded if it has the proper sized wire for the circuit breaker?

PeteD
01-29-2009, 08:46 PM
Not if the lights are not in the same area
No reason to run 14-3 to an outside light, then to an overhead light, then to another light in another room, then to a light in a bathroom, then to another outside light on the other side of the house
And not if the runs are 12-2, which is what the "test" referred to
And yes I have seen that many switches in 1 place, but they used a 4 gang box for more room

I agree that it probably doesn't make sense from a practical standpoint. This situation would more likely in occur one room. Two lights in a single fixture and a light and a fan in another fixture for example, each controlled independently.

My comment was not meant to be directly related to the example (which was just a junction box - no switches or internal clamps), but rather to point out the box fill calcs can work for these combo switches and the box is not overly-packed.

Pete

jwelectric
01-30-2009, 08:04 AM
Is this a round box or a square box?

1) A 4x4x2-1/8 metal box (Round houses 9 conductors) (Square houses 13 conductors). So NO on both counts.

2) 18. The black and white wires account for 16, the ground wires account for 1. I am also adding 1 for the grounding clamp per 314.15(B)(2) of the NEC dealing with Clamp Fill states internal clamps should account for 1.

3) 4-11/16 x 2-1/8 square

First if it is a 4x4 it can't be round now can it?

Second on the test you will be taking the only correct answer will come from the book not from what we think

Master Brian
01-30-2009, 10:12 AM
First if it is a 4x4 it can't be round now can it?

Second on the test you will be taking the only correct answer will come from the book not from what we think


Well, the 2008 NEC stated a 4x4 round/octagone box! So, don't ask me, ask whomever wrote the code!

2nd, I know it isn't what I think. I just said what I would have done previous to reading code, which would have been correct, even though I didn't know the code. I stated that to show that not everyone whom does DIY stuff is an idiot and not all connections done by a DIY'er are incorrect and out of code. Common sense goes a long way!

So were my answers correct or not?

Master Brian
01-30-2009, 10:30 AM
First if it is a 4x4 it can't be round now can it?

Second on the test you will be taking the only correct answer will come from the book not from what we think

My question here is, if the code doesn't list a 4x4 size, they list is as 4 square or 4 round, am I supposed to guess? A 4" dia octagon/round box would still be 4x4 would it not? I would assume 4x4 means square, but I've also taken enough tests to know you don't assume on a test like this! It turns out to be "in material" in this case as there is obiously more conductors than either box will handle....

You state you are an instructor, I would think you would know better.....

Here is a screen shot of the 2008 NEC, please show me where they state 4x4 as being square.

sjsmithjr
01-30-2009, 11:03 AM
Try to think of this as preparation for dealing with inspectors and the counterman at the supply house city desk.

The original question stated that there was a "junction box. Metal 4" x 4" x 2-1/8" deep", so the box in question can't be round.

Square metal boxes provide maximum box volume and would make the best choice for a junction box with multiple conductors. That's not to say you can't use an octagon box as a junction box as long as your fill requirements are minimal.

I stand prepared to head to the dunces corner if I got any of this wrong, but at least I'll have learned something new.

jwelectric
01-30-2009, 11:17 AM
My question here is, if the code doesn't list a 4x4 size, they list is as 4 square or 4 round, am I supposed to guess? No I suppose that you should take your own advice you mentioned here;

Common sense goes a long way! If something is as long as it is wide or let’s say something was 4x4 then it must be square or at least this is what I was taught in the fifth grade.


So were my answers correct or not? Not


My question here is, if the code doesn't list a 4x4 size, they list is as 4 square or 4 round, am I supposed to guess? A 4" dia octagon/round box would still be 4x4 would it not? I think that even a fifth grader would know that anything that was the same on two sides would know that it is a square. I hope that you would know the difference between an octagon and a square. If my third grade math has not left me an octagon has eight sides and would need more numbers than just two. It would look something like this http://i3.photobucket.com/albums/y63/jwelectric/oct.jpg

As for a round box I think it is pretty easy to recognize as it is a circle.


You state you are an instructor, I would think you would know better.....
Here is a screen shot of the 2008 NEC, please show me where they state 4x4 as being square. One of the hardest things that any instructor has to overcome is the ignorance of the student. When a student thinks they already have the answers to questions it is really hard for the instructor to point anything out.
As to the NEC stating a box as being a 4x4, the members of the code panels feel that anyone that is messing around with electricity should already know a little something about shapes such as something being a 4x4 would be square.

Now I am not trying to sound mean or ugly but as you said yourself. “a little common sense goes a long way”

GabeS
01-30-2009, 01:36 PM
4x4 is two dimensional. Doesn't say the height of the box. 4x4x4 would be a cube. 4x4 doesn't apply to circles. Radius and diameter apply to circles.

A circle can't have a measurement of 4x4. It's impossible because it doesn't have any sides. It could have a 4" diameter. But that doesn't mean 4x4.

4x4 means length x width.

Volume is lenght x width x height.

Pie times radius squared is the area of a circle.
Two pie radius is the circumference.

A square is the same on all sides.

Master Brian
01-30-2009, 01:37 PM
I think you need to go back and look at a 4" octagon metal box, they aren't shaped as your picture shows. Well, they are an octagon, but the sides aren't equal as your picture shows. So, I can easily see someone just saying 4x4 box, maybe you in your advance state as an instructor would never do that, but others might....

I am however glad you finished 5th grade....when you further your education with a college degree and beyond, you'll surely learn not to assume anything!

Maybe I am wrong, please explain! Afterall you are the teacher, please teach! Was I wrong on what I would have done prior to reading the code? I am certain, I was correct! If not please enlighten me there as well. 4 wires max wouldn't have been overfill on any 4" box that is 2-1/8" deep. Crazy part is my common sense tells me, putting much more than that isn't safe, I didn't need to pass any test to tell me that. In my opinion taking the home owners test is just passing through the hoops....but if that's what it takes then fine.

Maybe I didn't read the code correct and that really comes from not wanting to waste a bunch of time flipping through online pages to check on the a couple of things.


One of the hardest things that any instructor has to overcome is the ignorance of the student. When a student thinks they already have the answers to questions it is really hard for the instructor to point anything out.
I haven't seen you point anything out, you skirt around acting arrogant, that is it! What I have learned in life, is the people whom are the most successful are the ones not whom think they know it all, but the ones that surround themselves with those smarter than they. I've never claimed to know it all, which is why I am here asking questions! I question why you are here, because all you want to do is mock and act like you know it all, when you clearly don't or you woudn't be here. Some are here to learn, others are here because they truly want to be useful, you seem to be here merely to self promote. Have at it!!


As to the NEC stating a box as being a 4x4, the members of the code panels feel that anyone that is messing around with electricity should already know a little something about shapes such as something being a 4x4 would be square.Is that a fact! You probably asked each and every one of them! I actually don't see the NEC stating a box being 4x4. NEC states it as being 4" square or 4" round/octagonal. You and one other person stated 4x4! NEC, was much more clear....they obviously didn't want confusion....

As for the common sense, I am paying attention to mine and disregarding you from here on out....

Master Brian
01-30-2009, 01:47 PM
4x4 is two dimensional. Doesn't say the height of the box. 4x4x4 would be a cube. 4x4 doesn't apply to circles. Radius and diameter apply to circles.

A circle can't have a measurement of 4x4. It's impossible because it doesn't have any sides. It could have a 4" diameter. But that doesn't mean 4x4.

4x4 means length x width.

Volume is lenght x width x height.

Pie times radius squared is the area of a circle.
Two pie radius is the circumference.

A square is the same on all sides.

If this is pointed at me, I understand what a square, circle and octagon are. I also realize that people state things that aren't 100% correct, so if there is any question, one should clearify. A simple, it was a square box, would have sufficed! Instead, there is no response and the response from the instructor isn't even a real response, it's heckling! I assume he is an instructor so he can self-promote....

What amazes me is how threatened some people are by people whom do things themselves. I don't know if they are threatened because they feel food is being taken off their plates or if they are threatened because someone else might be capable of doing on the side, what their life focus is....

GabeS
01-30-2009, 02:48 PM
It wasn't directed at you. Just at the general discussion of the entire post. I can't believe we are telling each other basic geometry. I doubt that's why people are on this forum.

jwelectric
01-30-2009, 04:12 PM
I think you need to go back and look at a 4" octagon metal box, they aren't shaped as your picture shows. Well, they are an octagon, but the sides aren't equal as your picture shows. So, I can easily see someone just saying 4x4 box, maybe you in your advance state as an instructor would never do that, but others might.... And it is the ones that would call an octagon or round box a 4x4 that will never get any understanding of box fill.


I am however glad you finished 5th grade....when you further your education with a college degree and beyond, you'll surely learn not to assume anything! Well for what it is worth to you I have a piece of paper with my name on it from North Carolina State University. I don't think I am the one assuming that a 4x4 is a round box now am I?


Maybe I am wrong, please explain! Afterall you are the teacher, please teach! Was I wrong on what I would have done prior to reading the code? That is like asking if there will be a blue truck parked in the store parking lot in the morning on the way to work. No one can say if you would have done something right until after you have done it.


I am certain, I was correct! If not please enlighten me there as well. 4 wires max wouldn't have been overfill on any 4" box that is 2-1/8" deep. This would depend on what you are calling a wire. If you are talking about four #4 conductors then it would not be compliant.


Crazy part is my common sense tells me, putting much more than that isn't safe, I didn't need to pass any test to tell me that. Common sense or not it would not be wrong to install as many as 20 eighteen gauge conductors in that box

In my opinion taking the home owners test is just passing through the hoops....but if that's what it takes then fine. To someone who fully understands the dangers involved with electrical installations it makes perfect sense to test someone on their ability before letting them continue to make electrical installation. To someone who does not fully understand the dangers involved with electricity they just can’t understand why someone should be required to take a test before being allowed to make electrical installations.


Maybe I didn't read the code correct and that really comes from not wanting to waste a bunch of time flipping through online pages to check on the a couple of things. Try as hard as I could I just couldn’t understand what you were saying here. I would suggest that anyone that is going to undertake making an electrical installation read the NEC and study it in detail


I haven't seen you point anything out, you skirt around acting arrogant, that is it! I think you might be a little off base here. You make the comment in your opening post that you have been reading the NEC so every answer I have given you has made reference to that book. I can’t understand why you think that by giving you the code section in question I am not helping you.


What I have learned in life, is the people whom are the most successful are the ones not whom think they know it all, but the ones that surround themselves with those smarter than they. Well my friend I can promise you that this is something I do daily. Just yesterday I was in a meeting with the chair person of code panel 8 and the CEO of the NCAEC as well as others. I do make an effort to ensure that any information I give out is the best.


I've never claimed to know it all, which is why I am here asking questions! I question why you are here, because all you want to do is mock and act like you know it all, when you clearly don't or you woudn't be here. Some are here to learn, others are here because they truly want to be useful, you seem to be here merely to self promote. Have at it!! Spoke in a truly defensive manner. I get this type of statement all the time when I have pointed out to someone where and why they are wrong. There is nothing wrong with making a mistake except the lack in mental ability to accept the fact and admit it, 4x4 and 4 square is the same. It is you who made this statement;
Is this a round box or a square box?

1) A 4x4x2-1/8 metal box (Round houses 9 conductors) (Square houses 13 conductors). So NO on both counts. Now you can try to turn the tables on me all you want but the facts are there in plain sight for the entire world to see. A 4x4 box can not be round plain and simple.


Is that a fact! You probably asked each and every one of them! I actually don't see the NEC stating a box being 4x4. NEC states it as being 4" square or 4" round/octagonal. You and one other person stated 4x4! NEC, was much more clear....they obviously didn't want confusion.... If you can’t understand that 4x4 and 4 square is the same then you will not pass that test that someone is going to make you pass so you will look like a pet dog jumping through hoops.


As for the common sense, I am paying attention to mine and disregarding you from here on out.... Spoke like someone who (notice the use of the word who instead of the misuse of the word whom) truly does not have the ability to learn. So have at it!!

Master Brian
02-02-2009, 09:21 AM
It wasn't directed at you. Just at the general discussion of the entire post. I can't believe we are telling each other basic geometry. I doubt that's why people are on this forum.


Don't ask me, I really didn't think it was a big deal. I just saw it listed differently in the NEC codebook and thought I should clarify!

Like I mentioned before, I think some people just like to try to make themselves feel smarter.

Master Brian
02-02-2009, 10:12 AM
Spoke like someone who (notice the use of the word who instead of the misuse of the word whom) truly does not have the ability to learn. So have at it!!

If you are going to criticize someone's grammer, you might first want to make certain you have it mastered yourself! Actually it's "Spoken"! Think my 3y/o has that one mastered. You messed it up at least twice, along with several other things in your last post alone! I would have let it pass, but you are obviously in need of perfection!

As for the size of the wire, that was clearly spelled out, we were discussing 12/2. Maybe you better stop your assumptions.....

As for the part you couldn't comprehend. I didn't want to "waste time" flipping through an online manual one page at a time, when it takes about 30sec per page on a 700+ page manual! IF a printed copy had been in front of me or I could have chosen the page # to go to, I would have done it. Had other things to do at the time.... Sorry that was inconcievable to your far superior brain!

Sorry, I had to glance back at the car wreck....human nature!:rolleyes:

jwelectric
02-03-2009, 02:58 AM
When doing an electrical installation the most important tool anyone can have is a current copy of the NEC. To just ask someone if this is right or if that is right is not getting the job done correctly.

The price of a current copy of the NEC is a lot less than having the inspector come back for another inspection.

But then again maybe some use a butter knife instead of a screwdriver.

Scuba_Dave
02-03-2009, 12:11 PM
You can't use a butter knife?
Can you talk to my wife :D

Buying the NEC handbook was one of the best things I ever did