Portable Generator: What size to get?

[Gatorboy]

I do not have electric yet at my property, and when I start building my pole barn, I will need some power to run my circular saw, plus an occassional drill, radio, etc.

What size generator would you recommend? (3000, 4000 watts?) Does the brand/engine really matter that all much? Have you had any "bad" experiences with certain brands?

Any insight would be appreciated.

[hazmat]

Gatorboy it is real easy to figure out

Watts = Volts * amps

Insert your amperages as needed

Saw = 115 X 15? = 1725
Drill = 115 X 7? = 805
Radio = 115 x 2? = 230
Lights
Other tools?
Total so far = 2760

Add up whatever you are going to run at the same time then throw in an extra 1000 for future expansion.

[chevdog]

I just bought a portable generator as a Harbor Freight closeout and in my opinion it was a bargain at $499 for 7200w peak/6500w running capacity, It's actually a Dayton unit sold by Graingers for about $1300. Engine is an 11hp B&S Vanguard and it has not missed a beat.
They currently offer a slightly smaller capacity version at $459 - just check out their website.
Both have 7 gal gas tanks as I recall, so there's plenty of runtime available.
I'm not associated with H-F or anything, but I think it was a great deal. Some of the stuff they carry I would not buy, but for this I could not pass on it, especially for needing a saw or drill out out on the "north forty" somewhere [img]/forums/images/icons/grin.gif[/img]

[GaryM]

Hazmat's right about figuring capacity needed, but you must allow for starting loads on motors. Some can pull almost double their running current when they start.

This website http://www.electricgeneratorstore.com/howtochoosri.html
has some information on choosing a generator.

I bought a 5500-watt, Generac from Home Depot for my pole barn, er, Kubota Shack. I run a Skill 77 to a table saw or radial saw and a roofer’s compressor all the time. . It works great!
Cost about $400.
This is probably not necessary for a pole barn, but if you put a generator in your house, as I did, I recommend you find a friend who is a member of the IBEW. They know so much about how to make the things work correctly and can save you time.
I work in electronics engineering about 60 hours a week (wife claims more) and I will never hesitate to hire a good electrician. They save you time, money, and you have fun at the same time.
That has been my experience-hope you have the same!

Nice Car!

[knucklehead]

Yeah, nice car - whazzat, a Desoto?

We went through the generator thing back during the ice storm in the Northeast. Gary is right - allow 2 to 2-1/2 times the amperage for starting your largest motor. We sized our unit to start our water pump, after thinking about what we'd want, and what we'd do without (dryer, electric oven, etc).

For shop use, the same applies. Find the largest motor you have, and multiply by 2.5 to get your peak draw. If you follow the operating and not surge wattage of the generators, you'll get a little insurance.

Generators are noisy - you can re-pipe them into a small auto muffler to help, something I plan to do when I get it semi-permanently mounted. Home Depot has a nice slection for touching and feeling, as you learn your way through it. We got the Generac contractor model (6500 W). I went for the full pressure lubrication, and overhead valves.

Northern Tool has the largest catalog selection I've seen. There are a lot of "rules of thumb" in there. and you can comparison shop. My brother got the Honda liquid cooled generator, and it's a cadillac, but 2x what I paid for the same power.

BTW, just after I shelled out $1400 for it, I found out a few hundred more would have bought me a gasoline powered welder/generator. [img]/forums/images/icons/frown.gif[/img] [img]/forums/images/icons/frown.gif[/img]

Just thought I'd mention that......

[chevdog]

knucklehead - Modified Packard [img]/forums/images/icons/grin.gif[/img]
hmmm - buster<font color="red">57 </font color> - I wonder if you've got some Chevy in your background [img]/forums/images/icons/cool.gif[/img]

Back to the generator - good comment to recommend an electrician. I've done an awful lot of home wiring, but I decided to leave the installation of a transfer switch for the generator on the new house to an electrician. I can identify the circuits for him, but better to have him do it.
<font color="red"> </font color>

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] Not to put too fine a point on it, but nobody so far has mentioned RPM. [img]/forums/images/icons/tongue.gif[/img] If you want to go "long term" with a gen set, you MUST go 1800 RPM and not 3600. The Kohlers in RVs are all 1800 RPM for quiet operation. A guy told me that there were some motor home wrecking yards in the Midwest that sell the gen sets for 500-700 bucks. Now THOSE, buddy, are gen sets, not this Mick Mouse stuff you see in the home de-provement stores. [img]/forums/images/icons/crazy.gif[/img]

If you want quiet that Honda series is excellent. They also have a power saving mode that idles it down when there isn't a load and idles it up when you have a load. I have one for my horse trailer and it is quieter than the propane ones that they put in them.