Wire - Stranded vs. Non-

[Melbo]

The latest code I am aware of is to use thwn in an approved enclosure (conduit etc).  That will come in stranded or solid and the insulation "should not" deteriorate.

HTH

Melbo

[Seayfam]

The latest code I am aware of is to use thwn in an approved enclosure (conduit etc).  That will come in stranded or solid and the insulation "should not" deteriorate.

HTH

Melbo

Did you mean thhn instead of thwn?  I just never heard of thwn myself. If you meant thhn then that is a stranded wire.

[Seayfam]

I was wrong on the thhn.. it also comes in solid

[Melbo]

THWN is for outside use and inside use --- I didn't look up what is necessary in an RV just normal code --- THWN is available like THHN in stranded or solid --- Last time I needed some they had it at Lowe's or an electric supply house.

HTH

Melbo

[kyle4501]

From Wikipedia :
THWN stands for "Thermoplastic High Water-resistant Nylon-coated
THHN stands for "Thermoplastic High Heat-resistant Nylon-coated

For more information, see also http://www.usawire-cable.com/pdfs/THHN_THWN.pdf

Both are gas & oil resistant. I don't believe NM romex is. Then again, If I've got oil & gas inside my coach, I probably have bigger problems than what wire I used . . . . 

[babell2]

In My conversion I will be using all Stranded. I am used to the Aviation industry and NO aircraft ever uses a solid conductor in any application. I believe it is a vibration thing. All large wiring is not only crimped but soldered after for better connection.

[Nick Badame Refrig/ACC]

Yup, here we go again.... lol

This is taken from our tech archives section under Green Book.

This is why you should NOT use extention cord wire for your bus wiring...
http://www.magnet.fsu.edu/usershub/safety/documents/extensioncord.pdf

Disallowed Uses Of Extension Cords
The following uses of extension cords are not permitted at the NHMFL:
• Extension cords may not be used in place of permanent facility wiring. Cords shall not be attached to building surfaces or structural members. They shall not be permanently concealed in walls, ceilings, or under floors - including raised computer floors.
• Do not run cords through moisture, tied to over-head pipes, across traveled roads, under carpets, or across areas of high foot traffic.
• Extension cords may not be run through doors, ceilings, windows, holes in walls, or through hinged door openings in enclosures. This is to prevent "pinch" damage to the cord. If it is absolutely necessary to run an extension cord through a doorway or open window for short-term use, the cord must be protected from damage should the door or window slam shut; it must be removed immediately when no longer in use; and must not be a trip hazard.
• Do not use extension cords that are frayed, cut, or damaged such that inner conductors show, or that have outer sheaths which have pulled loose from their molded plugs exposing the inner conductors. In particular, do not use a cord that has a bare conductor exposed.
• Detachable multi-tap adapters may not be used on extension cords nor on receptacles.
• Cords may not be repaired with electrical tape, nor may tape be used for other purposes on a cord. It may conceal damage.

Cord overload and overheating:
In addition to the total electrical load, the conditions of use affect extension cord safety. Rated capacity for an extension cord assumes it will be used in an open-air and straight configuration.
As electric current passes through a wire, electrical resistance causes some voltage drop and heating of the wire. Coiling or winding excess cord length can concentrate this heat and overheat the cord. Similarly, covering a cord with a rug or rag can trap heat and overheat the cord. This trapped heat can damage the cord and lead to a fire. Tying a knot in a cord can have a similar outcome.

[Len Silva]

I've been away for a few days and missed all the fun.  A couple of comments;

THHN, THWN and hundreds of others are insulation types and have nothing to do with cable types.  They are only of concern if you are wiring in conduit. What we are interested in is the CABLE TYPE.  Type NM (Romex) or type MC (Metal Clad, similar to BX) are what we commonly use.

Fred Hobe is a very talented bus builder and I have long admired his workmanship and common sense approach.  However, I very strongly disagree with his use of extension cords for wiring.  If I ever bought one of his conversions, I would have to rewire it before I could sleep in it.

Dennis,
There is no RVIA book, it is the NFPA 1192, Standard On Recreational Vehicles, published by the same people who publish the National Electric Code.  It has nothing to do with the manufacturers and does not cover AC wiring.  It does cover low voltage wiring (stranded), plumbing, propane, ventilation, etc., and would be a very valuable and inexpensive ($40.00) addition to any bus converters library.

Whether to use stranded or solid wire for your AC wiring depends on whether you have separate waste tanks or a single tank 

[bevans6]

Technically speaking, is an "extension cord" still an extension cord if you cut the ends off and permanently wire it and fasten it in place?  I suspect that it is not.  At that point it becomes "wire" of a particular type and with whatever approvals it carries.  I bet the rules related to extension cords don't cover the use of "extension cord wire". 

Brian

[Len Silva]

Technically speaking, is an "extension cord" still an extension cord if you cut the ends off and permanently wire it and fasten it in place?  I suspect that it is not.  At that point it becomes "wire" of a particular type and with whatever approvals it carries.  I bet the rules related to extension cords don't cover the use of "extension cord wire". 

Brian

It has nothing to do with whether or not it is called an extension cord or "cord set" in NEC speak, it is the cable type which is not permitted.  Extension cords are typically type SJ  and it's many variations, (SJE, SJO, SJEO etc.

Article 400-8 is what prohibits their use.

It's not really a subject for debate.  It's use is against the NEC.  Whether or not you choose to follow that code is your business.  You will not go to jail.

[bevans6]

that's interesting.  I knew the use of the cable type wasn't allowed, I just didn't know if there were separate rules for extension cords.  I guess you can get or make extension cords of different kinds of cable other than the typical.  I make extension cords of different types of cable sometimes, for example for the 30 amp cable to a generator.  Regardless of the cable type, I don't think you can run them through doors permanently, or all the other restrictions.  Those are use restrictions, not just cable type restrictions.

Brian

[robertglines1]

To this uneducated person if I saw a extension cord used as wiring I would think it was a cheap move and not trust the rest of the conversion Quality.  Being proper for a particular use in the mind of a uneducated potential buyer;might question the rest of the systems. After finding a brown 2 wire cord in present project(a pro converted coach) I replaced all of those areas and Questioned the rest of the conversion.   The use or non use is perceived application decision. I use stranded run in conduit. Price difference is very minor between the two.  Bob

[bevans6]

When I got my bus home, the ac wiring was extension cords and power bars...  everywhere!  Step one, complete rewire...

Brian

[luvrbus]

You guys need to spend a few hours at a converter for the buses they make a wiring harness on a long board for that floor plan tie strap it together and go throw the harness in put a few tie downs and off to races, same with the ac side except they install it on the opposite side and sometimes they don't even do that 


good luck