Wiring Type

Originally Posted By: jburkeson
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All,


I have been an electrician all my life, first time I have ever seen a house wired in #14 twisted-pair. The house was built post WWII and it looks like it was wired with government surplus cable. The wire itself has no visible identification marks on what looks to be 600V rated insulation. Does anyone have a clue what desigination this wire falls under?


[ Image: http://www.nachi.org/bbsystem/usrimages/more/IMG_0015.JPG ]


--
Joseph Burkeson, RPI (Hooperette)

?Anyone who has proclaimed violence his method inexorably must choose lying as his principle.?
~ Aleksandr Solzhenitsyn

Originally Posted By: jpeck
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jburkeson wrote:
... first time I have ever seen a house wired in #14 twisted-pair.

Does anyone have a clue what desigination this wire falls under?


Falls under 'recommend re-wiring'?

This may be one of the VERY FEW times where 'further evaluation' is warranted, but not just 'further evaluation', it deserves further explanation to justify it. Something to the effect of ...

"The visible electrical wiring used in this house is of a type we have never seen before, and we suspect that all wiring, visible or not, is of this same wiring material. There is no marking on this wiring to indicate that it is rated or approved for use in household wiring systems. We recommend that an electrical contractor come out and do a hipot (high potential) test on the insulation to check its dielectric insulating ability. If that meets or exceeds what is required, the electrical contractor will need to decide what other tests and investigations are needed to verify whether or not the wiring used in this house is accept and SAFE to be left in place. Short of doing the preceding, we recommend re-wiring the entire house."

I have seen similar wiring, but not 14 AWG, maybe 16 AWG, used for real old door bells, ringers, and the like. I've never seen it used for the whole house, though.


--
Jerry Peck
South Florida

Originally Posted By: Greg Fretwell
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If the stuff is what I am thinking of it is similar to type TW stranded. It is certainly not “legal” but I doubt it is that much of a hazard as long as it is protected from physical damage.


I agree it is probably WWII surplus that someone got cheap/free.


I’m not sure who is really qualified to “certify” it as being OK since it can never be code compliant. If the insulation is in good shape and the workmanship satisfactory it will probably be OK but it sure should get a warning to the buyer.


Originally Posted By: jpeck
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Greg Fretwell wrote:
I'm not sure who is really qualified to "certify" it as being OK since it can never be code compliant.


Exactly my point.

Re-wire the house.

Quote:
If the insulation is in good shape and the workmanship satisfactory it will probably be OK but it sure should get a warning to the buyer.


And that warning should include the FACT that they, the buyer, MAY end up having to pay to re-wire FOR THEIR BUYER when they sell.

Now, should they live there and re-wire for the next purchaser, or re-wire for themselves? Right now, they have the option to try to negotiate $$$$ from the seller for this. Then they get to make the decision as to whether the negotiation was sufficient for them to buy the house.

Can Joe MAKE anyone re-wire? Of course not. Should his client be knocked upside the head with the fact that, if not re-wired NOW, THEY MAY (may) have to pay to re-wire later, for their buyer. Again, that becomes their decision. You, the HI, has not taken any decision away from them, you have only given them the information they need to make their decision.


--
Jerry Peck
South Florida

Originally Posted By: Greg Fretwell
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I am only saying this may not be as much of a hazard as K&T or pre-AA8000 aluminum.


Folks in Chicago say Romex wired homes are death traps and there are plenty of people who say wirenuts are baby killers.


As long as the homeowner is informed the HI has done his job.


Originally Posted By: jpeck
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Greg Fretwell wrote:
I am only saying this may not be as much of a hazard as K&T or pre-AA8000 aluminum.


"May" being the key word. K&T is well known and, during its time, the 'latest technology'. In a way, older aluminum might be more dangerous as it basically a 'failed' product. K&T is not a "failed" product.

Quote:
Folks in Chicago say Romex wired homes are death traps and there are plenty of people who say wirenuts are baby killers.


Yep, same place where the trade unions who refused to allow PVC plumbing DWV. Do they allow it even now?

In Chicago, NM cable is referred to 'rope'.

Quote:
As long as the homeowner is informed the HI has done his job.


I guess the key is how you define "informed". Yes. As long as the buyer is "informed" of what you find AND its consequences, then they get to make up their mind.

I "inform" my clients.

Because these emergency egress windows are too high, too small, and there are non-removable security bars installed, this bedroom is Fry Room 1 and this bedroom is Fry Room 2. Anyone trapped in here is not likely to get out alive.

See? I just "informed" my client that there is no way out of those bedrooms during a fire or other emergency.


--
Jerry Peck
South Florida

Originally Posted By: dbozek
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I agree with Jerry…umm wow that’s twice in one week. icon_eek.gif Rewire the house…or at least the circuits using this stuff. It does look like old doorbell wire.



You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

Originally Posted By: Greg Fretwell
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I suppose we are all guessing about what the wire is but your WWII surplus comment had me thinking about that wire the Army used to wire up tents and stuff in the jungle and if that is what this is it will outlast the house.


I agree it ain’t code and you can’t really walk away without making a deal about it but it may not really be that bad.


Originally Posted By: jpeck
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Except all that old WWII wiring was rubber insulated, and rubber insulation dries out, cracks, and fails.


I would not put much faith in it. Remember, that was before the advances made in "Plastics my boy, plastics." 'Here's to you Mrs. Robinson ... '


--
Jerry Peck
South Florida

Originally Posted By: Greg Fretwell
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Was it crumbling? I didn’t see that.


Originally Posted By: jpeck
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Greg Fretwell wrote:
Was it crumbling? I didn't see that.


Probably cloth covered, you wouldn't see the crumbling. About the only time you see the crumbling is when you take a close look at where it is stripped back at the terminal, and see the tiny pieces of insulation laying on the bottom of the enclosure and the cracks in the insulation where the cloth is frayed back.

This is the same reason many of the older two-wire wiring systems need to be replaced. Rubber insulation has dried out and failed. Remember, the insulation is not there for protection from physical damage (although it does help with that), but for electrical shock, ground fault, and short protection.


--
Jerry Peck
South Florida

Originally Posted By: jburkeson
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All,


From what I saw of it which was quite a bit, and in the attic no less, was that the insulation was in very good condition. It seemed to be a combination of rubber and some type of silky fiber which was very smooth to the touch not like cloth covered wire. The wire itself was solid tinned copper, or that is the way it looked in the panel.

Here is what I said in the report.

"Branch Circuit Conductor Type: Mixed - Romex and open 2-wire twisted pair - Open twisted pair wiring does not and never has met code. Evaluation and replacement by a licensed electrician is recommended
Cost to replace: $2000.00 - $2500.00. See the Repair/Replace Recommendations Summary."


--
Joseph Burkeson, RPI (Hooperette)

?Anyone who has proclaimed violence his method inexorably must choose lying as his principle.?
~ Aleksandr Solzhenitsyn

Originally Posted By: jpeck
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Hoe B.,


"Mixed - Romex and open 2-wire twisted pair "

Just a finer point of interest.

RomexTM is a brand name. NM cable is the generic name. Unless you know it is RomexTM, you should probably refer to it as NM cable, which is what RomexTM is. Non-metallic sheathed cable, or NM cable.


--
Jerry Peck
South Florida

Originally Posted By: jtedesco
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Joe B.


I looked into an old 1928 electrical catalog I have, and the closest that I came to the description you gave was a similar type of twisted wire that was identified as a fixture wire.

That twisted pair probably was on a small reel and found its way into someones collection of wiring.

Up until a few codes ago the term "Romex" was in the NEC Index, and it was because it is a term that is copyrighted that it was removed.

The same thing happened with "Greenfield" which is Flexible Metal Conduit.


--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

Originally Posted By: jtedesco
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jpeck wrote:
Except all that old WWII wiring was rubber insulated, and rubber insulation dries out, cracks, and fails.

I would not put much faith in it. Remember, that was before the advances made in "Plastics my boy, plastics." 'Here's to you Mrs. Robinson ... '


Jerry: Here is some information that supports your comments.

Quote:
Volume XIV May 1942

NEWS Bulletin of the

INTERNATIONAL ASSOCIATION OF ELECTRICAL INSPECTORS

WAR PRODUCTION

The government has one prime object in all its efforts regulating production taking advantage of every possible means for assuring ultimate victory for this country.

The whole program of the government in restrictions, priorities, allocations, and other forms of regulation is aimed at this one purpose, and every activity in which the individual is engaged must be judged on the basis of its value as a part of this major program.

As Donald M. Nelson, Chairman of the War Production Board, has so aptly said:

"None of us can give up more than the individual who gives up his life in the forefront of battle."

The various government orders that affect the electrical industry, and that are abstracted in the following pages, all have as the one object: the winning of this war!

The personal desires of every one affected must be subjugated to the good of the whole the maintenance of this nation.

CRITICAL MATERIALS

The Bureau of Industrial Conservation of the War Production Board issues from time to time reports on the relative scarcity of certain materials.

This list is subject to change at any time. The following items in which the electrician is interested, is from the list dated March 12, 1942.

In Group I are the materials most vitally needed for war purposes. They are not generally available to civilian use: steel, aluminum, cadmium, chromium, iridium, lead, magnesium, nickel, tin, tungsten, copper, long fiber asbestos, rubber.

In Group II are included essential war materials whose supply is not as critically limited as Group 1: mercury, mica splittings, platinum, reclaimed rubber, shellacs, and zinc.

In Group III are included materials available in some quantities for other than strictly war purposes. These materials are restricted or limited: common asbestos, asphalt, brick and tile, cement, slate, concrete, wall board, plywood, and silver.

PRIORITIES

On April 7, 1942, Donald M. Nelson, chairman of the War Production Board, stated that WPB orders already issued or about to be signed provide for the virtual cessation of consumers' durable goods industries using critical metals in the United States and the conversion of their men, plants, and facilities to an all out war effort.

Some production is still being carried on, but within three months almost all of it will be stopped except for that production necessary for war and essential civilian purposes and replacement parts.

Order L 65

The War Production Board on March 30 ordered manufacturers of electrical appliances to discontinue at once the use of certain critical materials in the manufacture of a long list of electrical appliances commonly found in American homes.

Between March 30 and May 31 these manufacturers, some 200 concerns that normally produced approximately $60,000,000 worth of appliances annually, may produce appliances at a rate of approximately one and a half times their rate of production in 1941, though without the use of critical materials prohibited by the March 30 order.

After May 31 they must halt production of all appliances except to fill orders or contracts bearing preference ratings higher than A 2.

The production of replacement parts is not affected.

The order affects such common household appliances as electric toasters, waffle irons, flat irons, roasters, grills, table stoves, portable heaters, food mixers, juice extractors, percolators, dish washing equipment, dry shavers, hair dryers, permanent wave equipment, hair clippers, cigar and cigarette lighters, and heating units for new electric ranges, water heaters, and radiating heaters.

Rubber

The need for the conservation of rubber was brought home to the American people by the restrictions on automobile tires. The necessity for rubber conservation extends to all uses of rubber, however, and as rubber is the most common form of insulating covering for electrical conductors, the electrical field will be very much affected.



--
Joe Tedesco, NEC Consultant

www.nachi.org/tedescobook.htm

Originally Posted By: dbozek
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Take a piece of 14 gauge K&t and never exceed it’s ampacity. Now take the same piece and exceed the ampacity. What’s the difference in the insulation of that same piece of wire now?


I have been in homes over 100 years old and have seen both scenarios. If the wire has not been abused by overloading it....it then is safe in my professional opinion. Part of an electrical safety inspection in this area is to determine the condition of the wiring in a house. This is done by inspecting the attic, the basement and typically in ceiling light fixtures. What is in the walls cannot be inspected unless the wall is opened. Another way to verify the condition of the wire is to look at the panel. In houses with k&t, typically you would see a couple of 20 amp breakers or fuses which supply the kitchen. The rest.....and absolutely the rest should be 15 amp breakers or fuses. The only exception here is with the dryer and range circuits which should be 30 amps and 50 amps respectively.

30 and 20 amp fuses or breakers on 14 guage wire indicates an overloaded condition and will most assuredly, dry out the insulation of the wire. Otherwise, I attest that k&t is actually safer than modern building wire. I'm sure I will get a lot of feedback on this one.... ![icon_lol.gif](upload://zEgbBCXRskkCTwEux7Bi20ZySza.gif) I always do. You first Jerry


--
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

Originally Posted By: jpeck
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dbozek wrote:
Take a piece of 14 gauge K&t and never exceed it's ampacity. Now take the same piece and exceed the ampacity. What's the difference in the insulation of that same piece of wire now?


What does amp load have to do with the insulation (unless it is very high and starts heating the conductor up)?

INSULATION has to do with protecting the circuit from grounding out, shorting out, being accidentally touched and the resulting shock. They don't rate insulation in amps, they rate it in voltage - for a reason.

The temperature only comes into place for ambient temperature and for those higher ampere uses where conductor heating takes places. Even then, the insulation is rated in temperature, not amps.

Thus, Dennis, you have either confused yourself or me, and I will admit that at times I am easily confused.


--
Jerry Peck
South Florida

Originally Posted By: Greg Fretwell
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I think he was saying it was overloaded wire (too many amps) that cooked the insulation. It usually happens in the boxes of ceiling fixtures (luminaires) first.


BTW Does “luminaires” sound like a singing group from the fifties to anyone else but me? Blue blazers and skinny ties ?


Originally Posted By: dbozek
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Exactly…overload a wire, exceed it’s ampacity…you heat it up…when you heat something up it draws moisture from it…thus the insulation becomes dried out…brittle to the touch.


Just like putting a 100 watt lamp in a fixture rated for 60. The heat generated from such eventually dries out the wires in the fixture. Most common problem found in k&t is at a light fixture. Sorry if I confused anyone.


--
You cannot help men permanently by doing for them what they should and could do for themselves. Abraham Lincoln

Originally Posted By: jpeck
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Ever heard of rubber tires dry rotting?


Same thing. Rubber hardens, 'dries out', become brittle and cracks. The entire process affects the insulative value of the rubber, then, when it cracks, it makes a good spacer grommet (as long as it is not against a thin edge, like a junction box, etc.), okay, it is not even a good spacer grommet because it will crack.


--
Jerry Peck
South Florida