Wiring color protocol ?

[DavidGraves]

Howdy

I wondered why FWC used white color wire for the hot main lead from truck battery to isolator ?

Is there a color protocol that dictates this ?

I am rewiring my truck batt to camper batt with 4 ga.

Inside the camper I might as well use the color FWC chose...thinking of future owner of the unit etc.

As I am old, I always wanted to call Red the hot lead and Black the negative when around vehicle systems.

Thanks

David Graves

 

[Happyjax]

David,

I have been confused more than once by wiring conventions. In house wiring black is hot..... electronics (DC) black is ground. I'm like "really people"

So I would run my DC house wiring based on my electronics background and use Red for + and Black for - . I would avoid chassis ground if possible but if I was going to do that I would probably use a green wire so I would know later that it was not a closed loop to my component.

I think the most important thing would be consistency and documentation. Now just to be clear I have not wired a camper but I have installed many radios and other electronics in my job so that is how I would approach things. I would also go heavy on the wire so if a job could be done with 16g I'd probably grab 14g if I could. Bigger is generally always better in wiring IMHO

 

[craig333]

I have no clue why there is no consistency but its important to realize its not just campers and houses. Always check first.

Maybe it has something to do with a horses a$$

 

[DavidGraves]

Thanks

It dawned on me I will go Red hot Black ground to the big plug in truck bed,..

within the camper I can match OEM and leave a note for future owner.

David Graves

 

[Bad Habit]

A/C wiring has very defined requirements dictated by the NEC (White - Grounded Conductor or as usually called, Neutral, Hot is Black, Red, or Blue in the case of 3 phase 12/208, Brown, Orange, Yellow for 277/480. Other colors are used after a switch, Green is the Grounding Conductor)

I think correct DC wiring follows along with the Common (-) conductor being white, with the Hot (+) being black. I think the Red (+) comes from the automotive industry and is where most typically run across it. My Hallmark is all White and Black and I do have to catch myself to remember that.

 

[Happyjax]

I have been an electronic technician for over 30 years and I have never seen black as anything but negative/ground in electronics. In computer wiring Black is neg., red is usually +5v and yellow is usually +12V Green is always chassis ground.

I do not know if there is a code for wiring RV's but I would follow the truck battery convention of black being negative and red being positive.....

YMMV

 

[Squatch]

Happyjax gives good advice. For 12 volt I use RED+, BLACK-, WHITE can be a secondary+ such as a branch. Or in some cases the 24v +. Green I use for common ground or as a color coded load wire.

I try to stay with automotive colors as I believe that is what most people will go by when dealing with 12 volt wiring. But even that gets confusing. Most use white for trailer grounds.

The best thing you can due is to label the wires and what they feed as loads. Doesn't hurt to also make a wiring diagram and keep a copy in the camper. Sure helps when you need to do repairs in the field.

When I rewired my Eagle I used Red/Black marine wire.

 

[JaSAn]

The majority of my experience with DC has been with automobiles. So, red (or colors) are positive and black is negative, with the exception of some European cars used brown as negative.

Bad Habit's response peeked my interest.

It seems that it depends on the country of origin, grounded to earth or not, and the standard used:

http://www.allaboutcircuits.com/textbook/reference/chpt-2/wiring-color-codes/

It's confusing at best. In the US the convention seems to be red = positive, black = negative for ungrounded systems (which our campers are). But for a grounded (to earth) system: white = ground for either positive or negative ground DC systems.

jim

 

[Vic Harder]

wow, this is confusing. I just wired mine and went with RED as directly connected to battery (fused) and colored as branch circuits. Black is ground directly connected to battery, white as circuit grounds.

I think the point Squatch makes is excellent... document what you did and keep the doc handy. I would add, be consistent!

Vic

 

[Squatch]

I also keep copies of the manuals for the various components such as furnace, fridge, battery separator, charge controller, ect in the camper. You never know when they might come in handy on a trip.

 

[Mark G]

I'm more curious about the choice of 4 ga. wire. The capacity of that is 70A. That's 840 watts at 12 v.

 

[JaSAn]

I'm more curious about the choice of 4 ga. wire. The capacity of that is 70A. That's 840 watts at 12 v.

I'm not sure what DavidGraves (OP) has in mind, but for me voltage drop is the controlling factor. My batteries need 14.4 volts in absorption. To get that I need 4 AWG wire.

If my batteries are at 50% they can accept 30 amps:

my alternator puts out 14.7 volts,
2% allowable voltage drop = 14.4 volts.

22 feet round trip alternator to house batteries,
200ºF wiring temp rating,
60 amp fuses on both ends,
connector between truck and camper,

= 14.4 volts at house battery = happy battery =

jim

 

[Vic Harder]

I'm not sure what DavidGraves (OP) has in mind, but for me voltage drop is the controlling factor. My batteries need 14.4 volts in absorption. To get that I need 4 AWG wire.

If my batteries are at 50% they can accept 30 amps:

my alternator puts out 14.7 volts,
2% allowable voltage drop = 14.4 volts.

22 feet round trip alternator to house batteries,
200ºF wiring temp rating,
60 amp fuses on both ends,
connector between truck and camper,

= 14.4 volts at house battery = happy battery =

jim

I like the way you think. My batteries need 14.7 in absorb, so I went with 2awg from the alternator.

If Mark is thinking about the solar panels, then yes, that would be a bit weird.

 

[JaSAn]

I have 4 AWG from my roof to my charge controller, < 1% voltage drop. There was a $5 difference between 4 AWG and 8 AWG. Might be overkill but batteries are usually back to 100% by noon.

jim

 

[Mark G]

I'm an electrical contractor so I think differently. I'm fine with the solar and all. Just not familiar with auto charging systems. I was surprised to find vehicle alternators that put out 200A and more. That'll run a small house!

 

[JaSAn]

In my career in mechanical engineering, I worked closely with DC circuit designers. They (especially the ASIC designers) would obsess over voltage drop. Their obsession was beat into me and put to good use when I decided to design my solar charging system.

Those 200A alternators were produced to power those lovely stereo system that rattle your teeth from half a mile away (curses on whomever designed those things).

jim

 

[Happyjax]

Some might even be used on a winch system...... plus you get to listen to loud music while you pull yourself out of a ditch.....lol

 

[Old Crow]

I'd think conventions for wiring colors in our campers would have to fall under national standards. The problem is getting a look at those standards to track down that thought.

Color conventions could be in Recreational Vehicle Industry Association (RVIA)'s publication "ANSI/RVIA Standard for Low Voltage Systems in Conversion and Recreational Vehicles". (Table of contents). However, I see that section 4-4 (Conductor Identification) is on page 9.... and so are sections 4-5 through 5-3. The print must be very small! Or perhaps they just refer to somewhere else.

Perhaps they're in the National Electrical Code Article 551 - Recreational Vehicles.

Anybody have access to either?


PS- I'm not an electrical guy, I'm just reading the web. This post in a teardrop builder's forum got me started on this train of thought.

 

[Mark G]

NEC Article 551 specifically excudes the wiring within the vehicles.

 

[Vic Harder]

I'm an electrical contractor so I think differently. I'm fine with the solar and all. Just not familiar with auto charging systems. I was surprised to find vehicle alternators that put out 200A and more. That'll run a small house!

200A at 12vdc is only 2400w. VERY small house