Power Inverter Question

[Jim Smith]

Just Got A Power Inverter ( 400 Watt) For Christmas And Have A Question On Usage. Could I Use It To Power Some Of My Electrical Appliances On My Rv Running It Off Of The Truck? How Long Will The Truck Run At Idle With A Full Tank Of Fuel?

 

[2-ND TIME]

Power inverter

It would depend on the wattage of the appliance. And if they need how good of a sign wave to operate. What is the spec's of the 400 W you may only be able to run around ???? 300 W continously. Might be best to get something bigger???

 

[KBennett]

Appliances usually have a sticker on the back that tells you how many watts it will draw.



Watts is Volts X Amps.

If you have an appliance that is drawing 120 watts and on the input side of the inverter you are supplying 12 volts your current draw will be 120/12 = 10 amps. The output side will be supplying 120 volts so your current will be 120/120 = 1amp.

If you have an appliance that is drawing the full 400 watts then your current draw will be 400/12 = 33. 3 amps at the input of the inverter.



2nd Time is right you may only be able to run a percentage of what it is rated for continuously. I have powered my laptop and a Sony Playstation with a small TV on mine at the same time and it was drawing about 10 amps.

 

[bulabula]

Just Got A Power Inverter ( 400 Watt) For Christmas And Have A Question On Usage. Could I Use It To Power Some Of My Electrical Appliances On My Rv Running It Off Of The Truck? How Long Will The Truck Run At Idle With A Full Tank Of Fuel?

Using Ohms Law, if you're going to plug it into the cigarette lighter, and that circuit is protected by a 20A ckt brkr, you will only be able to draw about 12W*20A = 240W before the breaker trips. A little short of the advertised 400W.



Those little inverters are good for little electronic toys, small tv, computer, etc, but useless for pretty much anything else - especially if it makes heat like a coffee maker, hair dryer. Dunno about small drills or impact wrenches.



If you want full performance you should wire it directly to the batteries. If you're still curious, there's nothing wrong with hooking it up ahead of time and plugging anything you've got to see if they'll work.



I've high idled my 3rd gen for an afternoon powering my 2kW inverter that was running a couple of wet-vacs after a hurricane last summer. Fuel consumption was nil. It'll idle a LONG time before running out.



hth

 

[Jim Smith]

Thanks, I'll Try To Hook Up Something. 2kw Where Do You Get One And How Much? My Son In Law Ran A Small Jig Saw Off Of His (smaller Than 400w) And It Worked Ok.

 

[AMink]

You will have to hook it to your battery for full usage. If you draw too much from the plug, the fuse will pop. The smaller ones are good for charging camera batteries or running small electronics, as stated. Sometimes you can pick up a bigger one at Costco for a good price. If you do decide to get a bigger one, make sure to read the directions as they get a little complicated if you intend to do a permanent install.

 

[Pawpaw]

You can buy the larger inverters at any truck stop, but they'll cost more $$$.



As others have stated, you'll need to wire it directly to a battery. Be sure to use large enough wire and put a fuse as close as possible to the battery.



If you don't know how to figure out what gauge wire to use, then don't try it yourself. Pay a professional to do it for you.



Installing an inverter isn't particularly difficult, but one little mistake can burn up your truck or trailer.



Bob



PS. A large inverter will quickly run your batteries down if the turck isn't running.

 

[bulabula]

As always, safety is paramount when working with high amperage devices. You don't necessarily want any uncontrolled "arc welding" going on under the hood of your truck - 300 Amps + is not uncommon with large inverters.



A good place to learn about hooking up a large inverter is searching through solar powered websites - they are low voltage/high amperage systems. You can find tables etc to calculate current draws, cable size vs cable lengths and fuzing requirements.



Good places to look at and buy those cables and fuzes locally are your Boat US kinds of stores - and those parts are pricey.



Some inverters are pricier than others, and thats mostly due to the built in circuitry on how "cleanly" it converts the DC voltage to AC - is it a pure sine wave or is it a square wave? Some equipment require a more pure sine wave, and some eqpt can live without it.



Mine (I think it's a Coleman?) isn't one of the more expensive types, but it works great in running fans, refridgerators, vac's, and the such.