I'm having trouble finding the math or charts to help me determine what specific Gauge of 3 wire outdoor extension cord needed to run a 9-AMP electrical Graco Airless Sprayer 200 ft away from my house's outdoor 115 volt electrical outlet. One is on a GFCI breaker and the other is a regular outlet, if that makes a difference.

I can see 200 ft extension cords on Amazon in both 12 Ga and 10 Ga, but I can't buy either until I know if one or the other will work without damaging my sprayer, considering tool amp draw specification and voltage drop etc., this type of electrical calculation being outside my pay grade for this kind of work. I need to spray 700 ft of 6 ft wood fence on both sides with a solvent based stain. 12 Ga would obviously be easier to handle and store than 200 ft of 10 Ga cord, but it needs to be right out of the gate.

Small gasoline portable generator instead, an inexpensive one (if they exist) instead of that much cord ? I don't know.

Any advice much appreciated.

200 feet is a long run for any extension cord especially for something drawing that many amps. The bigger the gauge the better but I would look at a generator for that application plus you most likely find it handy in other applications. I think Woot just had a 2000 watt inverter listed for just over $300 the other day.

A google of 'wire gauge distance chart' will get you some results in images. The 5th-ish one says for a 10A motor on a 15A breaker, 10GA wire will get you 201ft from the PANEL.
That's direct wire, but your limiting factor is going to be the 12 or 14GA wire from the panel to the outlet.
I couldn't find anything from what looked to be an official source, but I'd say 200ft is pushing any extension cord, especially on a 15A breaker. Duty cycle will play a factor & I doubt you'll burn the house down or even trip the breaker, but voltage drop might be a problem at the sprayer, especially if it has a big start up amp draw.

Any way to have the pump closer to the house & get more paint hose? I've seen painters that looked like they knew what they were doing leave the pump in the truck & run hose through the whole house, at least 100'.

Snidera nailed it!

Maybe check with tool rental places?

Rent a small generator?

How long do you think it’d take to complete the job?

My local Home Depot charges $36 for 4 hours, $54 a day, $204 a week, for a Honda EU2000i , check your local store, and other tool rental stores, for prices.
.

10 ga

Graco "Ultra" series by chance? They feature a variable speed DC motor so you can run all the cord you want.

quote:

Originally posted by snidera:
Duty cycle will play a factor & I doubt you'll burn the house down or even trip the breaker, ...

Too much current draw over too much distance at too little wire gauge won't burn anything down or trip any breakers, but what it may cause is...

quote:

Originally posted by snidera:
...but voltage drop might be a problem at the sprayer, especially if it has a big start up amp draw.

This ^^^^^

Wire has resistance. More wire = more resistance. More resistance = more voltage drop. Too much voltage drop and things may refuse to run, may run poorly, or even be damaged.

Solution: Look up product's start-up and running current requirements. Enter relevant numbers into something like this: Voltage Drop Calculator

That calculator yields an approx. 7V drop over 200 feet of 12 ga. wire at 9A. For 125VAC that results in about 117VAC. Should be no problem.

Extension cord story...

I have this 100 ft. extension cord made from marine shore power cord I'd bought for our boat. I'd bought it on the assumption it was a 30A (10 ga.) shore power cord. Turned out to be 20A (12 ga.) stuff. I went out, bought the right cable, and moved the 30A shore power connectors to it.

Thought "Hmmm... that 12 ga. stuff would make a great extension cord, but how to manage it?" A buddy at work grabbed an empty plastic wire spool for a reel, bent up some conduit to make a stand upon which to mount it, I threw on 20A connectors, and made it into a seriously kick-ass 100 ft. 20A extension cord

Ensigmatic, that is a bad ass extension cord!

200 feet is a lot of cord . Heavy , bulky , and not cheap . Use a small generator .

You can easily calculate the drop as is noted above. For what you want using the industry standard voltage drop which really max at 5% drop the necessary cord is 8g. You won't find that easily. But 10g you can get most places.
I seriously doubt that you will hurt anything with a 200ft cord and increased drop, but as is noted above its likely that sprayer extension is substantially cheaper than cord extension. MY sprayer permits very longer spray hoses, but check on yours. 150ft of 10g fits in the allowable voltage curve.

Sounds like the OP is in the market for a battery-operated spray kit. Alternatively, perhaps a compressor on a long extension cord, and then an even longer air hose. I used the latter to staple fence fabric to a split rail fence before I switched to a cordless gun to avoid having to pull cables and hoses.

200 feet is too long IMO

I bought a SunJoe dethatcher which is 12 amps and it says you cannot use longer than a 100 foot cord.

Once again: A 7V drop over 200 feet of 12 ga. wire at 9A. For 125VAC that results in about 117VAC. Should be no problem.

Rent an inverter or generator or just see if you can rent the 10 gauge extension cord, lowes, HD or local rental place...

As I understand it, the govt regulators don't want the use of extension cords to be over 100 feet. That's why the largest extension cord you can find is typically 100 feet.

A agree that a 200 ft 12 gauge cord will give you everything you need.

I run 200 feet of 16 gauge cord to run an electric chain saw (9 amp draw) in my far back yard and it works perfect. Its only sporadic cutting, less than 8-10 seconds per cut, works fine. I know the cord is technically undersized, but I am an ID10T and don't care. The cord has never got too hot with such a low duty cycle.

quote:

Originally posted by architect:
. Alternatively, perhaps a compressor on a long extension cord, and then an even longer air hose.

Not going to work for the OP's Graco Airless Sprayer unless you are suggesting a windmill generator at the end of the air hose.

quote:

Originally posted by bubbatime:
As I understand it, the govt regulators don't want the use of extension cords to be over 100 feet. That's why the largest extension cord you can find is typically 100 feet.

A agree that a 200 ft 12 gauge cord will give you everything you need.

I run 200 feet of 16 gauge cord to run an electric chain saw (9 amp draw) in my far back yard and it works perfect. Its only sporadic cutting, less than 8-10 seconds per cut, works fine. I know the cord is technically undersized, but I am an ID10T and don't care. The cord has never got too hot with such a low duty cycle.

The issue is voltage drop and burning up the tool.

So far then it seems I still don't know for sure. I'll call Graco and ask them, being careful to try to talk to someone who really knows by way of lots of professional experience with airless electric sprayers. Hopefully I will be able to reasonably discern if they really know the correct answer, unless... there is no good answer, like some things in life. But damn this should be simple math, more or less, for a very specific application under known conditions, probably known by tons of professional painters. Maybe it's a conspiracy, they want me to HIRE them instead. No way. I'm gonna paint this damn fence come hell or voltage drop high water. Or not. Probably not until I find out the correct information.