cable current capacity

In article , Brian Su writes

I believe most car jumper cables are 25mm sq. Commercial vehicle jump leaads are 50mm sq. As American cars are generally bigger engines 35mm sq would probably cover it.

AWG gauge max safe amps OO 283

0 245 1 211 2 181 3 158 4 135

many of these tables available on the web, all wil vary. Most are continuous usage, you will probably only need to draw your max current during the actual starting of the other car.

But, at the cost per foot of 4 and 2 awg wire (not >Hello,

You anticipate jump starting a Yugo or a Cat D10 (it makes a difference)?

25 is a bit smaller than #4 50 is between a #2 and a #1 for we non-metrical folks

Good advice though.

Brian Su wrote in news: snipped-for-privacy@4ax.com:

The main issue is not, if they can withstand thr amperage, but the voltagedrop if you use thinn cables.

4 GAUGE is about as heavy as is used in "normal" circumstances. As indicated, even this size is hard pressed to carry the necessary starting current.

But the "fact of life" for car to car jumping is that, usually, what the really need to do is put enough charge into the "dead" battery so permit it to barely turn the engin over. The fatter the charging cable the more you can charge the "dead" battery and the more current will be available to "help" when the dead car's starter is engaged.

When I had cheap cables I would connect the two systems and keep the good car running for as long as I had patience (2 or 3 minutes) and THEN tried to start. I have used this technique to jump start a Buick Roadmaster from a

4 cylinder TOY.

I now have a near "top of the line" set (#4 from Wal Mart) but haven't used them yet. They are quite heavy.

Welding cable is the best bet for high amps. Then MTW ( machine tool wire, whole lot a little tiny wires, Humor). If you have to carry them far I would stick to 4, clamps are important also. Check the connections to the clamps and let that be your guide. I made a set a long time ago and had to use terminal lugs on the ends so I could make the connection to the clamps. They always got warm around that bolted connection.

Yes this would work but it can take a very long time to charge up the dead battery b4 it has enough CCA to start the engine. I've tried this before, using a low quality jump start cable, 12gauge to jump a 1.5L petrol engine car from a 1.8L car. It took about 5 mins and lots of revving on the 1.8L car and the cable heated up ALOT, it nearly melted because I engaged the 1.5L car's started several times while the battery was being charged.

If I had a good pair of cables back then, I'm sure it would have started up almost instantly w/o even having to run the other car's engine.

In article , Greg writes

My jump leads are 50mm sq and rated to start an engine up to 9 litre (9000cc)

I had a beefy set of cables made from some fat wire I got from an old mainframe power supply. It quickly demonstrated the limitations of the clamps.

The cable heated because the running car's alternator is capable of putting out 50 or more amps. Once its battery was charged, most of its unused capacity was available to charge the other car's battery. Through

12 gauge conductors.

Yes. But with larger cables the trick of letting the dead battery charge for a few minutes helps. That way, when it starts, less current will be drawn through the jumper cables since the partially charged battery will now contribute some current.

I have 2 questions,

1. What are single strand copper cables?

1. Is it better to go for a cable with less copper but thicker plastic sleever or one with lots of copper core but thin sleeve protecting it?

Thanks.

Solid wire? That would be pretty unwieldy.

Thick jackes are just a way to hide how cheap the cables are made. Someoner else gave you the best answer ... Welding cable. These are made for rough service and have very flexible conductors. The welding store can even crimp ring terminals on them for you. That makes it easy to connect the clamps. The problem is, you can probably buy commercially made jumper cables cheaper.

According to Greek Internal Installation Code, the wire gauge that can handle safely that ampacity is 150 mm2.

-- Dimitris Tzortzakakis,Greece

Ï Brian Su Ýãñáøå óôï ìÞíõìá óõæÞôçóçò: snipped-for-privacy@4ax.com...

Constant or Cyclic? Remember jump leads are short duration items, it is acceprable for them to heat (Up to a point). Not withstanding anyone elses point, I have the largest set I can keep in the car along with all my test instruments. 50mm sq. I have used 150mm in an emergency, but that is Portable Primary Earth gear for the 33kV Distribution Network. Large unweildy and you would have no space in the car. (Rated for a fault capacity of up to 1000MVA. You hopefully don't get that from a combustion engine alternator!)

Years ago ( close to 25 years now!) I bought a pair of booster cables made from #4 AWG welding cable (about 21 square mm). The main advantage of these cables over the cheaper ones sold at department stores is LENGTH - it is *very * useful to have a set of cables longer than the car you're trying to start.

These cables have outlasted several cars - I've used them innumerable times to start my own and other vehicles. In a climate where you can count on weeks of -25 C weather, good booster cables, and a 200-amp garage-style charger, are a better investment than an auto club membership.

Bill

Welding cable is excellent, because the insulation is very soft and pliable, and the cables have a large number of small strands, so they are very flexible.

And if the original poster lives whee it gets cold, that is what he wants. The harder plastic gets very brittle and breaks at colder temperatures (and just before it breaks, it gets to be about as easy to bend as a half-inch pipe). And the more strands, the better - the easier it is to coil the things up and tuck them out of sight when they are not in use, and the easier it is to route them around awkward little barriers.

HR.