OFC Cable

The AMP rating of cables is of little consequence if you are designing a system to have minimum voltage drops. The AMP rating of a cable is the current flow through the cable that will produce a considerable temperature rise in the cable (some say melt the insulation.) In the lengths involved in wiring our vehicles, if you use wire of just sufficient AMP rating then your system voltage drop will be too large.

PeterD

Justin

Do you know how to work out the voltage drop in your system. I am sure Mainey will be able to assist - he knows everything.

PeterD

Justin
As PeterD has said, you do need to know what size cable to use in the battery set-up to limit or have nil Voltage loss.
As you say-> ""Just wiring up some batteries in the camper.""

To ascertain the correct size battery cable to eliminate Voltage loss you will need to know what the "total distance" is from the CRANKING battery to the most distant battery and as Peter has said, if I can assist you I will.

Mainey...

Hi Guys

If you do a search for this article:

Cable Sizes & Conversions
by Collyn Rivers

(an excellent read)


you will find the following formula for calculating voltage drop

Voltage drop equals (cable length (in metres) X current (in amps) X 0.017) divided by cable cross-section in mm.sq.

My advice is don't be to excited about what capacity is claimed by the seller as length of wire and amperage needed are always going to dictate the size of wire required.

regards Kc

OFC is just something that sales orientated types get excited over. To us techos it is just a load of cows excreta, we just go home to our wives to get our orgasms. The finer wire is an advantage only for flexibility, nice to have but more expensive.

PeterD

Or goats!

shush Mike this is a FAMILY forum hahahahaha

Agreed.
The quoted electrical conductivity figures for OFC cable are generally no better than for standard Electrolytic Tough Pitch copper wire. Standard ETP copper usually equals or exceeds the International Annealed Copper Standard for conductivity.
The lower oxygen content in OFC is supposed to give a less brittle wire, of which higher ductility is one of the benefits, and better mechanical performance at high temperatures; ie, less brittle following welding. It is useful in glass-metal seals.
HiFi enthusiasts have argued for the last 20 years or so that the copper oxide crystals within the copper may act as small diodes, creating a small non-linearity in the conductivity of the copper, thereby creating imperfections in the sound quality; OFC purpordedly exhibits none of this.
As far as your DC wiring goes, choose whatever circular mil rating you need to carry the current in whatever grade of copper you like. If the dealer throws in OFC wire at no extra cost, take it.
Gerry