Automotive wire

Allany · Veteran Member

Automotive wire

exa41 · Guru

40 amps should be safe ,

Phil C · Guru

Found this table, 6mm square is around 2 or 3 AWG

Guys the table I inserted was copyright in the USA, so it is removed. I found it on google so one assumes its public domain, obviously not so. For this information go to google, its full of useful information on this subject.

Cindy, if I have breached forum rules I apologise.

Cheers

-- Edited by Phil C on Thursday 17th of September 2015 11:55:59 AM

migra · Senior Member

6mm is about 15 amps however you need to know the length of the wire to be accurate.

e.g. 3M length of 6mm is about about 25A

03_Troopy · Guru

6mm auto wire is about 4.2mm² which has a continuous rating of approx 35A. However, voltage drop would dictate it unwise to use it at full capacity.

-- Edited by 03_Troopy on Wednesday 16th of September 2015 06:26:26 PM

Allany · Veteran Member

So what size wire do i need for an Anderson plug on the back of the car to charge the van battery?

Allan

03_Troopy · Guru

You would be best of going with 6 B&S twin sheathed, which is 13.5mm² into a 50A Anderson PLug. The reason for doing this is to try and keep voltage drop down to a minimum. Run both POS and NEG all the way back to the battery and enclose it in some convoluted conduit where it runs under the car if you need to do that.
If you have a variable voltage alternator, you will need to fit a DC to DC charger close to the batteries you want to charge. You could use a "voltage booster diode" fitted to your alternator sense wire instead, but I believe the DC-DC charger is a better option.

PeterD · Guru

Allany wrote:
Does anyone know what 6 mm automotive wire is rated at in amps?

Alan, by now you will have gathered there is no easy answer to your question. When you see a rating for maximum current, that rating is the maximum current that can pass through it without overheating it. The heat is produced as a result of the voltage drop along the wire. If your wire is being used at its maximum rating and it is aver a couple of metres long you will probably have too much voltage loss for the appliance being supplied to work at its optimum capacity. Another way of expressing this is - if you design your caravan wiring circuits using the current ratings of your cable then you are guaranteed to be using wire that is too small.

The info given in some of the replies reflects what I am saying. If you don't have one of these many tables at hand you can work out the size cable then you can use the following formula.

Voltage drop = Length of conductor in metres x Current in amps x 0.017 divided by conductor cross section is sq. mm

This comes from this article. There is an explanation of how to use the formula in that article more discussion on the subject. There are more articles on van and trailer wiring on this page.

in transit · Senior Member

I have noticed that some Jaycar staff have an app on their phone. I think this is it.

play.google.com/store/apps/details

Just input source Voltage, Power/Current, and Distance and Wire Gauge Calculator will calculate the needed wire size in AWG and Circular Mils. Results given for both Copper and Aluminum Wire.

Might be worthwhile if you have enough use for it

Allany · Veteran Member

The wire that the dealer wired the anderson plug with is rated at 48 amps
I checked the manufacturer web site

I am going to upgrade to 6 b&s

Allan

03_Troopy · Guru

in transit wrote:
I have noticed that some Jaycar staff have an app on their phone. I think this is it.

play.google.com/store/apps/details

Just input source Voltage, Power/Current, and Distance and Wire Gauge Calculator will calculate the needed wire size in AWG and Circular Mils. Results given for both Copper and Aluminum Wire.

Might be worthwhile if you have enough use for it

Another good app is Electrodroid. It gives you a lot of useful calculators and converters for electronics enthusiasts.

Electrodroid App.