Big inverter

[brownbear]

So for some time I have been thinking about different sources of emergency power for my house. Nothing too crazy as I need about 2500 watts an hour to power it all. But I don't plan to do that. Just enough for the sump pump and one heater I think. Like a 1500 watt portable heater.

So I have looked at different generators, but they all look cheap, or too expensive. I have even thought about using a PTO type generator and going off the pto output on my H55f. But I am not sure I could couple it right.

I like the idea of my truck having the power with in. So then I saw the big 3000 watt inverters.

http://gateway.canadiantire.ca/driver.php?fileid=product11__0111846_

Not to expensive comapred to a 3k watt gen. But can a Toyota alternator handle it(55 amp)?

If I do the math watts divided by volts gives amps.... so I take 3000 and divide by 120, equals 25 amps. SO that would work. Not saying anything else is running, just the engine keeping it charged up.
But if take 3000 divided by 12 volts, its 250 amps. SO is it the input voltage you divide or the output?

I think the output. As 250 would be too high.

If I didn't want to run the engine on my truck I could even make a small gen with the inverter using a car alternator and small briggs or honda engine........??

I know inverters have a certain amount of loss, and they are not perfect. But simplicity of having it hooked up to your truck and being able to power ANY power tool is an awesome idea..

What do yall think?

 

[Japan4X4]

First check if that is 3000 continuous or 3000 peak, big difference and not stated.

Second find out what wave form it has, sine wave = good, square wave = pretty much not good.

 

[mobi-arc]

Divide by 12.

 

[78-FJ40]

I've always liked these inverters:

This is a 3000 continuous, 6000 peak.

http://www.donrowe.com/inverters/vector_3000.html

 

[MrMoMo]

Unfortunately... a 3000W inverter (at 100% efficency - which it is not) would put out 3000W (at 120V), and consume 3000W (at 12V). Very good inverters are about 90% effecient.

So. Lets say your 3000W inverter is 90% efficient, and 3000W is not the peak output but the continuous output. So... 3000W * 1.1 (additional 10% needed to run the inverter = 3300W input power. 3300/12 = 275Amps. Yes, you read that right.

Now, a little more accurate... if you are running off your alternator, you will likely get closer to 14V -that drops it down to 235Amps.

This is not all coming from theory, I have installed a 3000W inverter in a boat.

The kicker about inverters it the amount of TIME you want to run for. If you wanted to run your 3000W inverter from batteries only, at full power for 1 hour..... you would need 6 27series batteries (a pair of 27's is stock in BJ60 AFAIK)

Inverters are nice, but they require a LOT of input power. The boat that we instaled the 3000W inverter on had TWO 280Amp alternators, and 7 batteries. (and a genset!)

 

[MrMoMo]

Second find out what wave form it has, sine wave = good, square wave = pretty much not good.

Well, I wouldn't go that far... you need to look at what you will be running off it. If you are running lightbulbs, sump pumps and heaters modified square wave is perfectly fine, these items really don't care.

HOWEVER, if you are running electronics or other sensitve equipment you should definately stay away from square wave.

 

[brownbear]

great information all! Thanks a lot.

that clears the air up quite a bit for me.

Yah they consume too much power than to be run by a standard Toyota alt. More like the ambulance special. Which would be at max.

So maybe my idea of a PTO driven gen set may be an ideal power source.... here is one I wanted to hook up to a pto off the H55f.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200308467_200308467

 

[83bj60]

Yah they consume too much power than to be run by a standard Toyota alt. More like the ambulance special. Which would be at max.

You can modify an alternator to output 120V, but if you want AC it's going to be three-phase.

Your inverter installation should work anyway, as long as you use that 3000W capacity only for short bursts, using the battery as a capacitor of sorts while your alternator recharges in between burts. In any case running the engine for that kind of power is extremely inefficient. A portable compact generator would be much better.

BTW I got the 1,000W model (2,000W peak) at Crappy Tire for $75 just before Christmas, great value for the money. I haven't used it yet nor did I check its waveform, but I suspect it is modified sine-wave, which is essentially a stepped square-wave, much better to electronics than the old style square-wave 'brappers' (I call them that way because of the sound they used to make while running).

 

[MrMoMo]

We frequently install these on our boats... not sure on exact price, but it is twice the size of the inveter you were looking at... simple to install and wire, you can belt drive it off the front.

http://www.se-power.com/acpower-sps.cfm

(not affiliated, just used them before)