12 volt dc queston - Page 2
 

12 volt dc queston

Started by Bob Gil, August 31, 2008, 07:44:19 AM

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Bob Gil

Thanks to all I have got lots of info from this discussion.

Quote from: Brassman on August 31, 2008, 08:15:39 PM
Extension cords as hard wired are non code. Check the RV wiring code.

You can do what you want (as in non code--but you assume total liability.)

Where would I find this RV wiring Code that you speak of?

I have not heard of a code for 12 v DC and am unaware if there is one.  That again is the basic reason for this posted question.

Bob Gil
Fort Worth, Texas where GOD is so close you don't even need a phone!

1968 GM Bus of unknown model 6V53 engine (aftermarket) converted with house hold items.

Had small engine fire and had no 12 volt system at time of purchase. 
Coach is all 110 w 14KW diesel genrator

DrivingMissLazy

Len, I suspect that the DC telephone voltage was a nominal 48 volts as I recall from many years ago. If in fact that is correct, then the float voltage would be in the 52+ voltage range and all UL requirements would apply.

High voltage DC breakers are very special with a special arc chute and long throws to extinguish the arc. These items are also extremely expensive.

I did develop a procedure for breaking this high DC voltage by using a three pole AC contactor and connecting  all three poles in series so that there were three actual sets of contacts breaking the voltage. I really do not recall if that met UL requirements or not. It did work great and I could interrupt several hundred amps of 600 vdc this way.

Richard
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride

JackConrad

Quote from: Bob Gil on September 01, 2008, 11:13:07 AM
Thanks to all I have got lots of info from this discussion.
Where would I find this RV wiring Code that you speak of?
Bob Gil

Bob,
    When referring to extension cord not meeting code, I believe they are referring to code for AC (120/240) wiring. This would be the RV section of the NEC (National Electric Code). There are also several other AC electric codes including a USCG and a couple yacht codes that do not pertain to us.  I am not familiar with any 12 volt code, although it would be very prudent to make sure any load does not exceed the rating of the wire used (amps+ length of wire).  Jack
Growing Older Is Mandatory, Growing Up Is Optional
Arcadia, Florida, When we are home
http://s682.photobucket.com/albums/vv186/OBS-JC/

Kristinsgrandpa

For the record, the NEC in article 551, which covers RV's and RV parks, says this about low voltage systems.

"For information on low voltage systems, refer to NFPA  1192-2002 Standard on Recreational Vehicles and ANSI/RVIA 12V-2002, Standard for low voltage systems in Conversions and Recreational Vehicles"

The NEC no longer covers low voltage systems.
I haven't seen the new publication yet because my souce (freebies) for new NEC hand books doesn't get the low voltage publication. 

Ed
location: South central Ohio

I'm very conservative, " I started life with nothing and still have most of it left".

DrivingMissLazy

Quote from: Kristinsgrandpa on September 01, 2008, 12:36:04 PM
For the record, the NEC in article 551, which covers RV's and RV parks, says this about low voltage systems.

"For information on low voltage systems, refer to NFPA  1192-2002 Standard on Recreational Vehicles and ANSI/RVIA 12V-2002, Standard for low voltage systems in Conversions and Recreational Vehicles"

The NEC no longer covers low voltage systems.
I haven't seen the new publication yet because my souce (freebies) for new NEC hand books doesn't get the low voltage publication. 

Ed

I hope someone has a copy of the NFPA and ANSI/RVIA documents. I think that I have in the past reviewed every publication, including all the marine pubs up to and including LLoyds, and I never found anything discussing low voltage systems. That is not to say that it doesn't exist but if it does I would really like to see it.

Richard
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride

luvrbus

If you ever been to a factory where S&S are built I don't believe they have any type codes for 12v and 110v would be questionable.I know the higher end Rv use a aircraft type wiring system all in one harness and I am not crazy about that you burn one wire the whole harness has to be replaced been there, done that                          have a great labor day guys

Brassman

When I stated that extension cords as being non-code, that was in reference to the cords listed use as a portable cord (not hard wired). How this relates to 12V service I don't know. The applicable code is ANSI/RVIA 12V Low Voltage System Standard. I don't have this Code, so I was coming from the NEC.

JeffsMagicBus

  Hello!
I could never understand why Fred or anybody would use extension cords of any age to wire anything, ac or dc, in a motor coach! It might be good enough for a schoolie that's used for camping on weekends but I wouldn't do it on any vehicle period. I have an idea! Try going to Home Depot or Lowe's and buying some Romex. You know, wire that is made for the exact purpose. But it's expensive Blah, Blah, Blah...
Hey people, there's a right way to do something and a wrong way and it takes just as long to do it right as it does to do it wrong. As far as being double insulated big deal! That just means that there's two layers of insulation that will deteriorate due to the heat in the ceiling area instead of a single layer. I had to look twice when I first saw Fred's site as I couldn't believe what I was seeing. I was taught that if a person uses a tool in a manner other than it was intended that's a good way to have an accident. An extension cord is not suitable and should not be used in ANY manner other than it was intended which was to temporarily supply power in an area where none is available. I don't care if Fred does it, or anybody else, it's wrong. Kind of reminds me of the saying our parents used to say when we told them "everybody else is doing it" which they replied: "Would You Jump In A Lake If Everybody Else Did It?" Of course I said it depends on the water depth, temperature, time of year, etc. but you know what I mean.
What this boils down to is this... Is your coach, family's life, or somebody else's worth doing that just to save a few dollars? I mean Romex is maybe $30.00-$50.00 a box! Big deal!
I'm sure the multimillion dollar Prevosts have seven miles of extension cords in there...
Years ago I was working on an old mobile home and had to take some paneling down in the kitchen and to my dismay I found that some moron had wired one of the plugs with zip cord from a lamp! NICE...
I didn't intend to hurt anybody's feelings but I'm entitled to my opinion especially when I'm right.
 But I'm just a crazy bus guy who glued 8,400 pieces of wood to his ceiling 14 pieces at a time...
                                 Take Care,
                                                   Jeff :)

http://cid-c6ec323e6ef26dd8.spaces.live.com/default.aspx
WD4IHS :)

Blacksheep

Jeff not to dispute your theory but romex is definitely not the right wire to use. I personally would use ext cord if nothing else was availlable over romex.
By the way, I used stranded wire everywhere in the conversion except for a single cord for my water pump which is 12v.
Ace

JohnEd

Jeff,

C'mon now. You are among friends and fellow converters here.  Absolutely no need to "sugar coat" every little thing. ::) :D :D

I agree with you that using extension cord in not worth the savings.  It amazes me that extension cord is so much cheaper than solid conductor house wire.  I have thrown away a lot of extension cords because the insulation was cracking and I have never seen a modern house wire deteriorate in the same manner...if at all.

I think the original suggestion to use extension cord in the bus was to have spare cables that were color coded to use for 12V apps for meter lines and the such.  That might be OK as i will be dead and gone by the time that meter fails to operate 15 or 20 years down the road.  Another nice aspect is that you can pull new cables through the chase by simply splicing the cables together and "pulling". Whatever you use will work that way.

Extension cords to carry 115 Vac in the walls of a coach?  Really a BOZO idea....in my book.

John
"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
"We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light."
—Pla

JohnEd

And please note that stranded wire is NOT approved for use in RV's according to CODE. ???  WHUP! :o  Take that White Man. ;D

And I use stranded for everything myself. :-X  Screw the code on this one. >:( 

John the "mild".
"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
"We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light."
—Pla

JackConrad

Quote from: JohnEd on September 02, 2008, 02:13:54 PM
And please note that stranded wire is NOT approved for use in RV's according to CODE. ??? 
John the "mild".

John,
   Isn't THHN stranded wire approved for 120 volt if it is in conduit?  I certainly hope so, cause that is what we used for all our 120 volt wiring. Jack
Growing Older Is Mandatory, Growing Up Is Optional
Arcadia, Florida, When we are home
http://s682.photobucket.com/albums/vv186/OBS-JC/

JohnEd

Jack,

OOOPS!  In conduit you say?  OOOPS!  Forgot that.  HEH.HEH.HEH.

I threw away my 2003 copy of the code a year ago.  Not that I ever read it since highschool.  I read a post long ago that said that that spendy "marine grade" stranded was not legal as it wasn't code, but the THHN solid was legal.  I have since read a lot of posts that said the solid was legal and that it was used in "all" S&S.  Now, how could you know that "all" used it, just to be picky?

I would use the stranded on anything that vibrated or moved and I wouldn't suggest any do otherwise.  Code or no code.  I have had a brain fart experience with this however.  I have heard so many people say that Marine stuff wasn't legal and solid was that i assembled the info as "stranded" is not legal and that is a very strange thing. 

I wonder how many more of these are spinning around inside me?  Thanks for not starting your post off with "Hey, Stupid".  That would have better than silence, however.  A lot better.

Thanks,

John
"An uneducated vote is a treasonous act more damaging than any treachery of the battlefield.
The price of apathy towards public affairs is to be ruled by evil men." Plato
"We can easily forgive a child who is afraid of the dark; the real tragedy of life is when men are afraid of the light."
—Pla

DrivingMissLazy

Years ago, most marine cable was not UL listed because none of the marine standards did not require anything be UL listed. UL was for the commercial market place, not the marine market place. Building any product to UL standards is a costly and time consuming process.

More recently I have noted that many marine cables are also UL listed so I feel certain that you can now buy marine rated cable that is also UL listed.

I suspect that many of you would be surprised that the marine standards are generally much easier to meet than UL. When I started manufacturing marine products I just continued using our UL procedures and met all of the marine standards without any problem.

Richard
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body. But rather to skid in sideways, chocolate in one hand, a good Reisling in the other, body thoroughly used up, totally worn out and screaming:  WOO HOO, what a ride

PP

Quote from: JohnEd on September 02, 2008, 05:18:54 PM

OOOPS!  In conduit you say?  OOOPS!  Forgot that.  HEH.HEH.HEH.

I threw away my 2003 copy of the code a year ago.  Not that I ever read it since highschool. 

I'm trying to do the math here to see just how old you are. I would have guessed much more than the numbers suggest  :D You threw away a 2003 version and hadn't read it since highschool......