Thread: What size power wire for amp install?

I have a 500w rms amp that has a 50amp fuse. The wire run will only be about 3 feet.

What's the rule of thumb on what size to use? 4ga or 8ga?

4 gauge is good up to 900 rms

You'll be fine with 8 gauge, especially with such a short run of wire.

8 gauge will work fine but I would go with 4 gauge.

Here's my current dilemma. I don't want to spend money.

I have about 20 ft of 4ga wire, and 0 ft of 8 ga wire. My fuse holder takes 8ga wire. I mean, I could use the 4ga and cut off some of the wire, but then it doesn't fit nice n snug in the fuse holder.

Cable Gauge Chart

Based on my quick calculations you have 500W RMS x 2=1000W/13.8=72.46Amperes.

For short spans 8 gauge is sufficient.

opps




I gonna say this ,,,,, the worst thing you can do to an mosfet amp is restrict the power supply from the battery to the amp itself.... what it will do is cause a drop in volts being supplied to the amp when it is in use,(we call it a Drain to Source), therefore if you supply a MOSFET amp with insufficent power supply it will give less power.... and burn up the transistors inside the amp... not to mention your not getting the power from that amp for which it was designed to do.


good luck ,,,,, with whatever you do.. you have the right answer.... just do it..



unbelieveable

its a mono amp

so thats 500/13.8=36.23amperes

To determine the approximate current draw (in amperes) of your amplifier (or amplifiers), you must calculate first the total power of each amp (multiply the number of channels by the number of RMS watts per channel). If you have multiple amps, add up the total power figures to arrive at a grand total. Next, double your grand total power figure. Then, divide by 13.8.

500W RMS
500Wx2=1000W
1000W/13.8=72.46 Amperes

Ahhh, didn't see that. Thanks!

According to the chart, I will be well below the limit. Seriously tho, the amp is going to be maybe 3 feet away from the distribution block, probably closer to 1-2 feet (which then goes to the battery in the trunk through a 0ga wire).

Either way, 8ga should be fine, but I might just use the 4ga since I have plenty of it laying around.