Question about installing Inverter

I have never seen this but a buddy of mine swears he has one. He says he has a 1000w inverter that he can plug directly into a lighter socket. I called bs on it because the wires couldn't handle the load but he swears up and down he bought it like that from the retailer (harbor freight) I looked on their site and the only 1000 they have is a direct to battery one. The largest I have ever seen that can plug in is a 750w but the tech told me to get the full wattage you have to hook the battery cables in. The 12v connection would only provide about half of the listed wattage.

 

Well technically you could plug a 10000 watt inverter into a cig lighter socket. But I am afraid that your buddy is still limited to the fuse limitation of the cig socket. That circuit is going to be 15 - 30 amps depending on the age and model of the truck.

Watts = Volts times Amps.

So on a 12 volt truck, even if he had a 30 amp circuit to his lighter, the max wattage that you could draw from the inverter would be 360 watts before the lighter fuse popped. In other words, technically you could plug his theoretical 1000 watt inverter into a cig socket with no issue, at first. But as soon as whatever you PLUGGED INTO that inverter went over 360 watts, the truck fuse would go. You see?

Of course, he could always put a larger fuse in the fuse panel. But please let me get my marshmallows and a stick first.

 

Exactly what I was telling him. Although I didn't reference the whole fuse thing.

 

Welding cable is much more flexible and durable as well.

 

Do i have to ground a 3000 watt inverter.?

 

It should have a ground bolt on it. It would not hurt.

 

What size wire would i need?

 

Sorry to say, you are working on the wrong side of the inverter. The fuse is on the draw side from the battery and the inverter will draw 148+ amps at full draw on a 13.5 volt system to produce 2000 watts at 120 volts. go with the 200 amp fuse.

 

For AC current, 2000 watts divided by 120 volts would equal 16.67 amps. Yes, a 20 amp AC fuse would be fine.

He is talking about the DC power feeding the inverter. So 2000 watts divided by 12 VOLTS would equal 166.67 amps. As you can see, a 20.amp DC fuse wouldn't work.

Going a bit further, the inherent efficiency of a harbor freight inverter is low. You need to oversize the wiring feeding the amp. 1/0 or even 2/0 wire would be best, even on a short run. It will result in a cooler running inverter and a lower chance of vehicle fire due to overheated cables.