sundance-communications.com/forum Forums General General Telephone & Systems Information using ext cord 300' to power amp

You may want to buy a 250' roll of romex and make your own cord. You could always use the romex for something else later.

Congratulations!

Congratulations Skip.

We run power inverters in our service vans to power the battery charges, laptops, printers, ect.
And believe me there are not a perfect science. My experience has been if you got one that is rated for 600 watts you might get 3 or 4 hundred out of it before it heats up and must shut down and cool for 30 minutes.

I would go with the extension cord plan.
At Lowes or Home Depot they sell 12/2 with ground extension cord cable by the foot and the ends to go on.
And if your like me, your always needing extension cords for something.

Good luck and enjoy!

Congrats Skip!

I have a couple of 150' #12 cords that I made up many years ago when such things were cheap. I used them when I was pre-wiring new residential construction for cable and telephone. I ran a 1/2" Milwaukee drill usually with one cable but sometimes the site power distribution location made it necessary to use both. At 12 amps the result was noticable but not a problem. But keep in mind that those Milwaukee drills are designed for such use.

In your case it all depends on how much power your audio system requires and at 3 amps I would definitely use #12 and not worry.

-Hal

I know it wouldn't help for your case, but here at school we use 3 phase power distros for larger and outdoor applications. It's a 60 amp distro which is plenty for powering DJs or band equipment.
In your case I would just use 12 gauge wire like the others have said.

If you want Skip I can check some of the places around here/tampa and see what a cord would run you. I could meet you in Sun City/Ruskin area (grandfather is down that way). I've also got a Rexel and Graybar down the road so I could just buy whatever you need. Let me know.

Can't you just move the wedding closer to the outlet?

Just kidding.

Congrats!

Your basic car battery can have somewhere around 100ah available. Youll want to double check your actual battery because this may be as low as 50ah. A 100ah battery running at 400 watts gives you around 2.5 hours or runtime. This does not include any wattage used by the inverter itself. Thats a little too close for comfort in my opinion. You could use multiple batteries to be on the safe side. Are there going to be other devices hooked up such as CD players, lights, etc? AC power will probably be the best way to go.

Skip, I would check to see if your inverter is square wave or sine wave output. If I remember correctly, sensitive electronics (which a stereo would qualify as) sometimes do not like AC signals that are not true sine wave.

Any chance of leaving the truck running while the music is playing so that the alternator charges the battery?

As for a "drain test", connecting a 100 or 150W light bulb (or the stereo to be used) to the inverter and seeing how long it takes to trip on low input voltage (usually ~10.5V) would give you a "real world" run time.

I doubt you'd be pushing this stereo much past 50W. A long time ago, I had a 100W guitar amp. At full volume it was DEAFENING. Keep in mind that a 400W amp has enough power to drive 2 Marshall full stacks (16 12" speakers) wide open.

Jack

Go to Home Depot or Lowes, buy a 250' spool of 12/3 SJO cable, and a couple of connectors (I prefer Leviton or Hubbell). presto - a 250' cable.

You can always cut it into shorter cables later if you want.

Romex works in a pinch (ie: for a one-off use), but I prefer not to make extension cords out of it. Unless you are planning on later using the romex for it's intended purpose, I would not bother going that route. You don't end up saving that much.. and you won't be even remotely compliant with the NEC..

Unfortunately, HD doesn't have prices for bulk cable on their website.. they do show 100' 12/3 extension cords in the $55-65 range.