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You would be further ahead to get a SMALL GENERATOR that puts out 1500 watts or so... One of them would be the size of a milk crate and weight 25 pounds.. Put in a gallon of gas and it would run  4 hours..

Here is one generator --- on AMAZON

Here is an inverter.... if your pulling 40 amps out of your battery ( or more) ... you should have the truck motor RUNNING while using the inverter..

OK, dumb question from north of the 49th.....

WHY don't you park combine CLOSE to 120v power ?

My Gleaner A sat in my house driveway for a few months.....

..took wife 8 DAYS to notice it was gone and she'd walk by it 4-8 times a day

I would suggest ol' shameless should turn off that snow and cold maker machine and let the climate warm up... or park his combine by an electrical plug in.

  Thendrix, if you need block heaters, you moved to far north... cold of winter is bad enough where you might need them heaters.

 

 Put generator in cart and take it to combine, hide it so can't be seen from the road.. 

If you get an inverter and plug into the truck, the truck has to be RUNNING... Seems like a lot of waste ??

A 2500 watt unit will be good for 1800 constant... But this will weight about 42 pounds as it is a little bigger.. Get a 2 wheel hand cart / dolly and mount to that.

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 I'd Find a cart/ 2 wheel trailer & put genny in cart & take it to combine.

  To use hook extension cord from genny to block heater & start genny, go back to house drink a few cups of coffee and it'll be ready to run. 

Using an inverter to drive a block heater is akin to using a piece of spaghetti to drive a railroad spike...

Using a generic portable 1500w generator to drive a 1200w block heater is pushing your luck... I wouldn't go any smaller than 3500W, just so you don't work the poor thing to death, because the block heater is a purely resistive load- the hardest 'pull' you can put on a generator.

As for getting it moved around, a portable generator is an excellent thing to have on either a cart, or a pallet you can lock into the bed of your pickup truck, or on a covered skid with 3-point quick-attach that you can just hook and go...

but I would just go with 300ft of 10-ga extension cord, and when next spring comes around, rent a trencher, drop in some conduit, and pull a power feeder out there, put up a yard light on a pole, and put an outlet in a weather-enclosure on it, just for that purpose...

dr p wrote: Dave, just giving you a head's up, when you die we are going to put your brain in one of those glass containers they have on futurama.

"John Prine:  Please don't bury me, in that cold, cold ground..."

I'll draw a diagram of where to hook up all the wires, Doc... connect the output to my stage amp, and the ears to my microphone... ;-)

So there's some likely misnomers goin' on here, so just to clarify:

When you take a 300ft piece of 10awg 120v extension cord, and connect it to a 750w block heater, you have:

10AWG = 0.00109 ohms per foot, or 0.109 ohms per 100, or 0.327 ohms per 300ft, on ONE wire.  There's same on the OTHER, so for a round-trip, that's 0.654 ohms.

At 120v, 0.654 ohms constitutes a dead-short load current limit of 183 amps, for 22.018 kw.

Since your circuit breaker will either be a 15A or 20A service, the 0.654 ohms is not a significant loss.

Let's say you're using a 750w block heater.  That's 120v at 750w, which means the heater's resistance is 19.2 ohms, and the current flow to feed it is 6.25 Amperes.

So take that 19.2 ohms, and add it to the 0.654 ohms in your extension cord, and you'll have 19.845 ohms, which at 120v at the RECEPTACLE, you'll have a total current flow of 6.0468 amperes, and a total circuit power of 725.62ish watts.

you've effectively lost 750-725.62 = 24.38 watts.

But now you ask... But Dave... Where did those 24.38 watts go?

They were dissipated out the extension cord as heat.

Of your 600ft run (out and back), the wire's resistance dissipated that 24.38w at a distribution of 600/24.38 = 24.61 FEET PER WATT... and since they're side by side in the extension cord, that's 1 watt of heat disspated every 12.30 feet.

Now, a watt is a watt... and if you have 1 watt every 12 feet, that's 3.412 BTU (British Thermal Units) every 12 feet... or 1 BTU every 3.5 INCHES.

One BTU is the amount of energy it takes to raise ONE POUND of water (at room temp, that one gallon is 8.33lbs, so you're talkin' about a pint (that's 1.04lbs per pint)...

So 3.5 inches of wire, at that 750W heater's running load, will warm a pint of water one degree F...  In one hour.

By comparison, if you PEE on that wire, you'll raise it's temperature about 30 degrees in 30 seconds.

So in a practical sense, there's no incredible energy loss here.

Now if we do same for a 1500w heater, you'll see:

1500w @120v = 9.6 ohms and 12.5A

Wire's 0.654 ohms means 10.254 ohms total...

Heating circuit at 120v 10.254 ohms means you're limited at

120v, 11.70A, 1404.33 watts.

1500w - 1404.33 = 95.67w lost.

Distributed over 300ft (600 total loop) that's 0.318w per foot, or 1w every 3 feet or so.

If you do the BTU calculation, you'll see that all this loss brought up the wire heat by a factor of three...

But peeing on the wire makes it much much hotter.

Now for the kicker:  Adding lots of extension cord won't cause the breaker to trip...  Breakers trip from EXCESS current.  Adding an extension cord LIMITS current.

The reason why breakers trip, is because there's either a SHORT in the wiring (something damaged), or there's a bad connection on the wire(s) going to the breaker, causing THEM to disspiate heat (which then percolates into the breaker and causes it's thermal element to trip).

So the fright about running a long extension cord is for naught, unless you errantly run over it with lawn mower, snow thrower, or crush it with the tractor.

Using old overhead service entrance as the feeder for a far-reaching pole is an excellent idea, particularly if the SE wire is significantly LARGER than your supply breaker's trip point... I've done just this, as I had a significant amount of leftover SE wire after putting all my building service lines in underground conduit.  I don't like trees, ice, wind, or tall machines tearing down overhead wires, so they're all in conduit, down 30 inches below my feet.