what is the amperage limit of 12 gauge wire at 12vdc?

Question

it is stranded copperwire. the insulation jacket says that it can take 600v so I would assume that is a high quality wire. it is currently suppling power directly from my car battery to an ac-to-dc inverter. it spans about 10 feet, and it is a 350 watt inverter so it will be drawing about 30 amps at 12vdc. I currently have a 35 amp fuse built in with the wiring as well as a switch, the inverter has two 20 amp fuses built in. so I am wondering if I can simply add another fuse harness parralell to the current harness to meet the wires amperage limit. I am currious as to weather I can connect a bigger inverter such as 700 watts (about 60 amps) I imagine that that may be a bit much but it would be nice if you could tell me what AWG I would need

Answer 1

Here is a link for wire guage and current capacity. I can tell you I would never run 30 amps through a single conducter. But if you add additional wires in parallel, you can handle the current load. The problem is if one fuse blows, it will shift all the current to the remaining wires. So to avoid overload, fuse each wire at the minimum current necessary. That way if one fuse opens, the others will follow.

Here is the link.

http://www.powerstream.com/Wire_Size.htm

Answer 2

First, connecting fuses in parallel is not a reliable way to increase the current capacity. The problem is that the currents may not be evenly split between the fuses. One may take most of the current and blow and then the other will blow also. You would need to replace your fuse with a single fuse of higher capacity.

Second, 12 Gauge wire is listed as having about 1.5 Ohms/1000 feet. So if you have a 10 foot length X 2 for the return path also = 20 feet, then you have about .03 Ohms. So the voltage drop at 30 Amps would be about 1 Volt. Do you want to loose 8% of your power in the wires? I don't think so. A standard amount would be 3% Maximum. So you should go down to 8 Gauge at least and the larger the better.

Answer 3

This Site Might Help You.

RE:
what is the amperage limit of 12 gauge wire at 12vdc?
it is stranded copperwire. the insulation jacket says that it can take 600v so I would assume that is a high quality wire. it is currently suppling power directly from my car battery to an ac-to-dc inverter. it spans about 10 feet, and it is a 350 watt inverter so it will be drawing about 30 amps...

Answer 4

Dc Amp Gauge

Answer 5

nation electical code book has section around310-16. it wil show amp and awg tables. #12 is usualy good for 20 amps in a-c, 14-15amps, #10- 30 amps, #8-55amps and so on for copper. also isulation plays a big part is the equasion. some big trucks use welding type leads to run power to inverts.

Answer 6

What are you using a car battery for?
What is the purpose?

Wouldn't a simple generator set for 110 or 220 volts be far superior?

I use truck battery to run motor for diesel/gas pump for filling tractors/other fuel equipment and night light rigging and even a fan.

But my generator runs for all other uses.
Even got a line tied into my house panel box (ckt brk) for using my generator.
Case of power outages.