Electric Inverter Run off Tractor

[SPYDERLK]

My thoughts exactly. I am thinking he is good to go as is. I still think my Anderson powerpole connectors are a good idea for good connections and quick removal.

James K0UA

Cant fault those connectors. I was talking cheap and easy with the lug under a butterfly nut.
larry

 

[Egon]

After all is said and done it might be easier/cheaper to buy a small generator.

 

[SPYDERLK]

After all is said and done it might be easier/cheaper to buy a small generator.

Easier in the short run. A maintenance issue in the long. Not cheaper, nor as convenient since you can install or always carry the inverter on the tractor because of its small size.
larry

 

[Egon]

Easier in the short run. A maintenance issue in the long. Not cheaper, nor as convenient since you can install or always carry the inverter on the tractor because of its small size.
larry

The convinience may be a debatable matter. The generator allows for quite a few other jobs that could require AC power.

Some cost comparison from Canada.

http://www.canadiantire.ca/AST/browse/4/Auto/SolarPortablePower/Inverters.jsp
http://www.canadiantire.ca/AST/brow...4P/Champion+1500W+Gas+Generator.jsp?locale=en

 

[Joe1]

I do have a Craftsmen edger with a 3 hp sidevalve engine. I wonder what size alternator that would be able to handle. With a 3:2 reduction @ 3,600 rpm it would turn the alternator at 2,400 rpm. Anyone have any ideas about the size alternator it could handle?

 

[k0ua]

I do have a Craftsmen edger with a 3 hp sidevalve engine. I wonder what size alternator that would be able to handle. With a 3:2 reduction @ 3,600 rpm it would turn the alternator at 2,400 rpm. Anyone have any ideas about the size alternator it could handle?

All calculations are approximate.
3.5 hp X 746watts per horsepower=2611 watts.

Volt X Amps =Watts we will use 14 as the nominal charging voltage
and assume 85 percent efficiency for the alternator.. some may be more, some may be less.. this is a guess.

14 X Amps=2611 so = 186.5 amps X .85= 158 amps

I would derate this even more and say an 100 amp alternator would be fine

James K0UA

 

[Soundguy]

yep.. and in a real world situation, I'd devalue 746 to about 500 and call it safe...

that drops the 158 to 105

a perfect match for that 100a alternator that was sugested.

soundguy

 

[Egon]

The applied load may be the determing factor.

 

[Soundguy]

as the OP asked, 'what could be handled', james and I merely gave an estimate of practical max capacity.

OF COURSE real power produced and hp used and fuel used will depend upon electrical load. I don't believe anyone implied contrary to that.

soundguy

 

[Redneck in training]

I do have a Craftsmen edger with a 3 hp side valve engine. I wonder what size alternator that would be able to handle. With a 3:2 reduction @ 3,600 rpm it would turn the alternator at 2,400 rpm. Anyone have any ideas about the size alternator it could handle?

12V/24V Automotive alternator doesn't need reduction. Since two pole 110/220V/60Hz requires 3600 rpm it also doesn't need reduction. Four pole will require 1800 rpm.

 

[Egon]

as the OP asked, 'what could be handled', james and I merely gave an estimate of practical max capacity.

OF COURSE real power produced and hp used and fuel used will depend upon electrical load. I don't believe anyone implied contrary to that.

soundguy

Real power makes a choice of car type alternator a lot simpler as one is not limited to the amperage. 80 amp versus a 150 amp will not require much difference in power required to just spin it with no load. :thumbsup:

 

[Soundguy]

Real power makes a choice of car type alternator a lot simpler as one is not limited to the amperage. 80 amp versus a 150 amp will not require much difference in power required to just spin it with no load. :thumbsup:

the difference will be in power generated, not capacity. assuming the rebuilder or assembler used as good of bearings int he 80 or 150a alt, they will spinthe same under no load, and have the same lod characteristics as each other up to 80a, then past that the higher capacity alt will continue to provide more mechanical load as electrical load increases, that assumes same efficiency alternators.. etc.

soundguy

 

[Egon]

the difference will be in power generated, not capacity. assuming the rebuilder or assembler used as good of bearings int he 80 or 150a alt, they will spinthe same under no load, and have the same lod characteristics as each other up to 80a, then past that the higher capacity alt will continue to provide more mechanical load as electrical load increases, that assumes same efficiency alternators.. etc.

soundguy

Yup, still means there is wider range of alternators to choose from.:thumbsup:

 

[Joe1]

The main reason for a reduction of 3:2 was to have a mechanical advantage so the engine can maintain rpm as the electrical load on the alternator increases. I was thinking that would give about the same ability to turn the alternator as a 4.5 hp engine runing a direct 1:1 ratio. I also assumed than on an alternator, 2,400 rpm would be enough. In addition, I'm looking around a 63 amp alternator vice a 100 amp unit. My electrical draw off the battery would be intermittent and probably less than 15 amps except for startup draw.

Where am I going wrong in my thinking???

 

[SPYDERLK]

The main reason for a reduction of 3:2 was to have a mechanical advantage so the engine can maintain rpm as the electrical load on the alternator increases. I was thinking that would give about the same ability to turn the alternator as a 4.5 hp engine runing a direct 1:1 ratio. I also assumed than on an alternator, 2,400 rpm would be enough. In addition, I'm looking around a 63 amp alternator vice a 100 amp unit. My electrical draw off the battery would be intermittent and probably less than 15 amps except for startup draw.

Where am I going wrong in my thinking???

HP is HP. You dont gain much/anything in a gear reduction. V reg will just up the field voltage to get full alt output at lower rpm. There may be a sweet spot on the alt efficiency curve that would give a small gearing benefit. Yould have to study up. ...
larry

 

[Soundguy]

i agree.. hp is hp, and on paper, 1 hp is 746 some odd watts... and I like to use 500 as a more practical real world number.

on a gm alt.. for instance. the 12si.. 2400 is the rated running speed for 70% of amp rating. ie.. 70a @ 2400 rpm, on a 100a unit.. max rpm on that unit is a whopping 18000.. i have seen some with 10000 as a max.. etc.. etc..

soundguy

 

[ericher69]

Why not use/modify a Pelican case as a weatherproof enclosure for your inverter and permanently mount?

 

[Joe1]

Thanks you all for your responses. I appreciate the ideas and help.

 

[NICKB304]

as far as hooking up the inverter goes. why not buy a wireing kit for a reciever mounted winch.

Dutton-Lainson Wiring Harness for DC StrongArm Electric Winches w/ Remotes or TW9000 Dutton-Lainson Accessories and Parts DL24151

 

[Soundguy]

seems like alot of expense for something you can hanck and splice togehter real quick / cheaply.

but to each his own. some like molded conenctors and plugs.. etc.