27 vs 40 ton

My Split-Fire is 22 tons, with a knife. I've tested it fairly hard. Only two big 22"+ chunks of oakwith big knots at the cut have stopped it. Once the rounds were reversed 180°, they are easily split. Being a two-way splitter, the cycle time is 5 seconds or less.

 

Tonnage is over rated. I converted my splitter to electric and have it turned down to about 17 tons and it runs a 4 way like a champ. I am using a 3hp 240v motor and a 14 gpm pump. It is a push through design and it will split a lot of wood in a hurry. My single wedge is a knife and the slip on 4 way is a hybrid.

 

What is FLA on that motor again?

 

I can double check, but I’m pretty sure it’s 17 amps.

 

That would be more like 4 HP then...the "5 hp" air compressor special that I started out with was overrated at 5hp, FLA on it is 16, so its barely 4 hp.
I have another motor that I don't have installed yet, its 20 FLA, so true 5 HP...I'll be able to jack my pressures back up, not that it is really needed, 99% of the time.

 

Your cord becomes a limiting factor as the amps go up. I have a 100 ft 12ga cord on mine and it does fine. You should be ok with the same cord up to 20 amps, maybe touching 22 amps. Use an amp meter to set your shift and relief pressures so you don’t burn up the motor.

Mine is a 3hp motor. Many mfg’s over rate their hp numbers, especially on air compressors and shop vacs, so be careful. The plate on the motor will tell you the service factor (SF). That is how far above the rating it can go for short periods of time. It will be a 1 or 1.15 or something like that. A SF of 1 means no overload allowed and a SF of 1.15 would be 15% overload allowed.

I have run motors past their ratings and they don’t last long. I have also seen people build log splitters that used undersized motors and the motor would stop in tougher wood. Use a good sized motor, good conductors, a good power supply, and adjust your pressures to keep the motor at it’s rating and it will run for a very long time.

Here is a chart of motor hp and amps at different voltages. Newer motors are supposed to be more efficient than older ones.


I just checked mine and this is the plate. It is an old motor. I rescued it from the farm I grew up on as a kid. It powered the vacuum pump in the milk house for years and then sat unused for a long time as the roof fell in. The plate says it will use 15 amps at 208v and 14,5 amps at 230v. I am running it on 246v, so the amps should be 13.75. The service factor allows for about 16 amps max.

 

Yeah I have a 100' cord rated at 30A...its an RV cord that I scored new/unused for something like $50!
I'm pretty familiar with the motor stuff...do a lot of electrical/motor/control stuff at work.
I'm definitely pushing mine pretty hard on the rare occasion that I get an extra stubborn piece, and the pressure actually goes up to 1000-1500 psi to pop it open. (1500 psi would be about 9.5 tons of push/force from my 4" cylinder)

 

That’s a good score! What gpm are you running for the two stages? Mine is 14 gpm total, and 1.8 gpm on the high pressure side. It usually doesn’t have to go over 5-800 psi for most rounds, but does occasionally hot 1,500 psi. Sure is nice to just flip a switch vs pulling the cord and worrying about fuel/oil.

 

16 gpm total... I'll hafta look up the high pressure flow... IIRC it was a little more than yours
Edit: yup, 4.2 gpm in high pressure/low flow mode...too much IMO, but I got it to work, and I'm not changing pumps, so...

 

4.2 gpm at 1,500 psi is 4.1 hp. That motor is working pretty hard at that pressure. 1,200 psi is 3.25 hp.