Wiring for a linear amp..

For my heat. I used welding cables because they are flexable. Your brother is about wiring bUT that's at 120volts. So at 12v you need a larger gauge wire.

 

Outsider,

You are gonna get a thousand opinions on what to use. The first thing is to NOT use household wiring. While it may work, it is not what you need. I have just rewired everything on my truck to run a Texas Star sweet 16 and used High strand 0 gauge wire. Like HYweighman stated, 12v needs largerer diam. wire. Think of it this way: Small wire may fire it up and let it work, but you won't get all the voltage available. The larger the wire the easier the voltage moves. If your amp can't draw enough volts because the wire is too small, you won't be getting the most from the amp.
Good luck with the wiring. I found the cheapest place to buy the wire is Ebay. BUT shop it and read the fine print so you get what you actually are wanting and not some cheap wire. Good site to study if you really are serious and want to have a better set up is: http://www.k0bg.com/

Good luck and take your time.

 

Mostly depends on length of run from batt. I wouldn't go smaller than 4ga keep ground short as possible. Hit up google several sites that give max amp capacity for length

 

The wires coming out of the amp are fine. (probably no more than 12 inches long?) If you hooked them directly to the battery you would be O.K. But you can't do that so you need a larger diameter wire to get the power to the amp. I used 6 gauge trolling motor wire like they use in a Ranger boat to power my Texas Star 667V. Hayseed has a awesome set up so what he tells you is good advice........Texas Star Sweet 16....thats 1600 of those watt things!!!!! That is indeed impressive!! (your alternator will want to kick you in the groin though...lol)

 

I second hayseed's and 062's post, you can go as small as 4 gage wire, 0 is good too but 4 is what you need for 600 watts.

The thing to think about is what hayseed said, "Small wire may fire it up and let it work, but you won't get all the voltage available." so you understand this, I tell the people I help get ham licenses that they need to think about it like a power washer, a 20 feet hose and a water spigot. The power washer needs a good flow of water at a good pressure so you turn the spigot on full to get it the water but if you have a small hose, the water is restricted, the flow is small and the power washer doesn't do its job.

So with a water hose say the diameter of a pencil, you don't get the water it needs but with one the diameter of a magik marker, you get plenty of water. Wiring works the same way with electricity, the larger diameter of wire, the better current flow and less voltage drop for the amount of length from the power to the unit you have.

As for using romex, or household wiring, never ever use that in a truck, or a car for that matter. It is solid copper which is not meant to be moved once in place. The wire itself can break, but worst the insulation can rub off and cause a fire, the plastic will burn to the point you can lose your truck. This goes for any and all solid conductor wiring, do not use it. I've seen someone's custom Western Star burn to the ground, the guy just put his stereo system in the thing a week before and used solid wire without fusing the front end of the power (that is fusing at the batter connection >>>> another thing to do no matter what) so the insulation rubbed off under the floor mat and he didn't even know it was burning until he stopped at a light. Poof! all gone.

 

40 amp I would run 10 gauge, copper stranded, fuse it within 6 inches of the battery, and remember the negitive has to be just as large as the positive leads.

 

You did not state the length of wire you are going to use but assuming not much longer than 6 feet 8 Ga will handle 65 amperes, 6 Ga 95 amperes, 4 Ga 125 amperes, assuming a maximum wire temperature of 80 degrees C. For Hayseed his DX1600 is rated 100 watts in at 125 amperes yielding 1,600 watts out. For a DX667V figure roughly 65 amperes at rated output. Yours will likely be in the 60 ampere area at maximum output. Meaning 8 Ga will just barely suffice but will be hot if you are driving it hard for extended periods, 6 Ga gives you some headroom (especially if your wire run is a bit longer). 4 Ga would be overkill for you although fairly mandatory for Hayseeds Sweet 16 (though he is at the edge considering maximum output). Since he would only intermittently ever reach that output his setup fares well. For a good lifetime and reliability it should be kept to a maximum of 900 watts which I have no doubt he does.

However we are answering your question so I would say depending on how you run your setup 8 Ga will just barely suffice for an average run to the battery, 6 Ga is a far better choice, 4 Ga is really overkill in your situation. Unless you are unsure if you are ever going to run an amp like Hayseeds and wish to do an installation which will be good for future changes. As was mentioned keep both wires equal size and never ever run to the battery unless you have a fuse within 4 to 6 inches of the positive post, usually 5 or 10 amperes larger than the fuse at the amplifier. Imagine you are turned over on your side in a wreck, unconscious, with fuel leaking. The last thing you want to occur is a wire pinched to the chassis or body glowing white hot from there to the battery. Meaning always prepare for the worst case which says if the wire ever shorts you want power to disconnect at the battery. Obviously this also means use a fuse, never use a self resetting breaker and never trust a manual reset breaker. If in an emergency you need the circuit to blow, you want it to stay that way until you are having a better day.

 

Did you say you have two power and one negative leads out the back of the amp?