Electric motor (5HP) on gas log splitter?

   / Electric motor (5HP) on gas log splitter? #1  

jas67

Platinum Member
Joined
May 21, 2008
Messages
986
Location
Central PA
Tractor
Kubota B7610 + Kubota G1800-S
I am considering trying to devise a way to add a 5HP electric motor (true 5PH, you know, one that draws 23A from a 230V circuit, not the so-called 5PH that can plug into a 115V socket). I would like to make a quick-connect base-mount, and pump mount, so I can swap between gas and electric. I do 85% of my splitting at home, and it would be nice to set it up inside my shop, since it always seems to want to rain when I want to split wood. This would spare me both the exhaust and noise, not to mention not having deal with gasoline for it. Since these pumps use spider couplings, it should be easy to do the quick mount for the pump.

The gas engine is an 8HP, and the pump is a 16GPH 2-stage. Surplus center states that this pump requires an 8HP gasoline engine. They also state elsewhere that a 2X larger gasoline engine is required vs. an electric motor. I though HP was HP.

The hard part, is where to get an inexpensive (probably used) true 5HP motor that runs at 3450 RPM? Most motors this size seem to be 1725RPM. I could use pulleys (sheaves) to step the speed up, but that would complicate the design, and add inefficiency.

Surplus center has a 3450 RPM "5 HP Special" compressor-duty motor for $132:
https://www.surpluscenter.com/item.asp?UID=3508013006081775&item=10-2390&catname=electric

This motor only draws 15A @ 230V. By my calculations, based on this, it would be closer to a 3.5 HP motor, as 15A X 230V = 3450W / 745W/HP = 4.6. Most induction motors are about 75% efficient, so 4.6 X .75 = 3.5 HP.

Will this be enough motor for this pump? I don't want to go down a size in the pump, as just upgraded the pump from an 11GPM for more speed.

Any ideas on where to get a suitable motor for $200 or less?

Any thoughts, ideas, experiences on this type of conversion?

Thanks,
Jay
 
   / Electric motor (5HP) on gas log splitter? #2  
Will this be enough motor for this pump?

I can tell you are more an electrical guy than hydraulic....:D

I think an electric motor would act little different than a gas engine.....a gas engine wont blow any fuses if the load make rpm drop down....so with an electric motor, I imagine, you will need it sized so it can run the "whole pressure-flow show" with out problems.....
Hydraulic power is the product of pressure and flow, and you ask if your motor will be enough???...... without mentioning anything about the hydraulic pressure levels.....

Calculate the hydraulic power you need!!!!!

I have gone with the pump data from Surplus Center and your 5hp.....

Here is the whole "picture"......
electricsplitter16gpmtwostagepump.jpg
 
   / Electric motor (5HP) on gas log splitter? #3  
American log splitters has elec. motors or gas or both with 2 pumps of course.
 
   / Electric motor (5HP) on gas log splitter? #4  
Speaking generally, the reason you see larger engines used to replace electric motors in a given application is that motors can run at their rated maximum output continuously. Engines are often rated at their maximum output, which they can't sustain for too long; you'll find industrial and marine engines are more conservatively rated. My 1/2 ton truck is rated at 170hp..who would honestly expect it to run at that output for thousands of hours, let alone for a single work day?

Another thing you'll need to consider in the motor/engine comparison is the torque required. That electic motor will be putting out its maximum torque for you while it's running that pump. With the engine, your peak torque and peak horsepower could be at very different speeds.

When considering this, the engine with the right torque and power at the speed you need will most certainly have a higher horsepower rating than the electric motor replacing it.

I'm strongly biased in favour of electric motors. Pound for pound, they're the clear winner in terms of performance and maintenance...and as long as you're on the grid, it's the cheapest to run. Of course, much of my bias comes from being a welder: There's always a big generator nearby.

Can you change your work methods to do all your splitting at the shop and save you from having to maintain an engine at all? I personally prefer to haul logs home and do the final bucking and splitting there; no engine driven pump for me.

As for getting a 5 horsepower motor: If you have three phase power available, that would be best. A single phase motor is going to cost a lot more money than a three phase one. Where I get surplus motors, 95% of the stock is three phase. It'd probably be easier to find one with a TEFC housing in a three phase as well.
 
   / Electric motor (5HP) on gas log splitter?
  • Thread Starter
#5  
Speaking generally, the reason you see larger engines used to replace electric motors in a given application is that motors can run at their rated maximum output continuously. Engines are often rated at their maximum output, which they can't sustain for too long; you'll find industrial and marine engines are more conservatively rated. My 1/2 ton truck is rated at 170hp..who would honestly expect it to run at that output for thousands of hours, let alone for a single work day?

A log splitter engine doesn't run at max output continuously. Max RPM, yes. But the engine isn't under much load most of the time, only when driving the ram into the log.

As for getting a 5 horsepower motor: If you have three phase power available, that would be best. A single phase motor is going to cost a lot more money than a three phase one. Where I get surplus motors, 95% of the stock is three phase. It'd probably be easier to find one with a TEFC housing in a three phase as well.

I don't have three phase power available, so a single phase one it has to be.
 
   / Electric motor (5HP) on gas log splitter? #6  
I had an 8HP 2 stage snow blower that I fianlly got fed up with the engine on. It was TERRIBLE to start cold and not fun hot, then the starter died and it seemed like it was always out of gas or needing an oil change.

So, I bought a 5HP electric motor for about $130 and plopped it in place of that 8HP gasser and NEVER looked back. With the 8HP gas, you could stall the engine in wet snow, NOT with the 5HP electric, no way! I even fried the belt trying!

Gasoline engines are rated in terms of short-term PEAK HP, while electric motors are rated for CONTINIOUS duty at 5hp for example. Cont. duty of the 8 HP gasser is more like 3hp and maybe less.

All I can say is my machine was available with an 8hp or 11hp engine, the 5hp electric had as much effective power as the 11hp engine when I tired it out and maybe a little more.
 
   / Electric motor (5HP) on gas log splitter? #7  
A friend put an electric motor in a log splitter. I cannot remember the details, but he downsized the electric motor versus the gasoline in hp by quite a bit. He had plenty of torque and we had to weld extra brackets on the log splitter because it was warping from the torque. An electric motor will exceed its rated torque for long enough to split a log, and it will have a nice rest while you load another log. Also you are not using maximum torque on every log, unless your logs are identical. If the electric motor will not split a given log, put it aside and split if later with the gasoline engine. Go for it.
 
   / Electric motor (5HP) on gas log splitter?
  • Thread Starter
#8  
...So, I bought a 5HP electric motor for about $130 and plopped it in place of that 8HP gasser and NEVER looked back. With the 8HP gas, you could stall the engine in wet snow, NOT with the 5HP electric, no way! I even fried the belt trying!
..
All I can say is my machine was available with an 8hp or 11hp engine, the 5hp electric had as much effective power as the 11hp engine when I tired it out and maybe a little more.

I would find the cord much more annoying with a snow blower than a log splitter. At least the log splitter is stationery when you use it.
 
   / Electric motor (5HP) on gas log splitter?
  • Thread Starter
#9  
Tractor supply has two 3450 RPM compressor motors. The brand name is "REGAL-BELOIT". I've never heard of this brand, but the price isn't bad. $169 for the one, and $189 other. Both are spec'd at 5HP, but one is 15A, the other 21A (both at 230V). As I stated above in the info about the motor from Surplus Center, 5HP from 15A isn't possible, so what's the deal with the 5HP rating. The 5HP from a 21A motor is at least feasible. Anyone here have any experiences with these, or other Regal Beloit motors?
See links:

Regal-Beloit Electric Air Compressor Motor, 5 HP 15 amp - 3241192 | Tractor Supply Company
Regal-Beloit Electric Air Compressor Motor, 5 HP 21 amp - 3241281 | Tractor Supply Company
 
   / Electric motor (5HP) on gas log splitter? #10  
jas67 .

Here is a 7 HP, at 3450 rpm single phase. 220 v.

sale-bxbju-1582220814@craigslist.org

We have an overstock of 7.5HP Leeson Electric Motors. We are letting some out the door for Super Low prices. This item can be picked up in ATL or Shipped to Jax for Free....... 7.5HP---Single Phase----3450 RPM------ This Heavy Duty Motor weighs 110 lbs -------
184T Frame------------208-230 Volts--------- 1 1/8" Shaft ---------- 32.0 F.L. Amps ------------------1.15 Service Factor --------------- Leeson Model # 132044--------------List Price on this motor is $815.25---------This Motor is Brand New in the Box with a full
manufacturers warranty--------------- This motor is American Made--------------You will not find a better deal on this motor anywhere in the country, and i mean anywhere------------------you can find all of the specs on this motor by visiting....
LEESON Electric a pioneer in energy efficient motors has expanded its product range in energy efficient electric motors ... and using the part # in your search------------------If your application calls for a 7.5hp 1725 rpm motor, you will find that motor costing in up-wards of $750 American made. This 7.5hp 3450 rpm motor we're selling will still work on your application, you just need a new pulley... which we carry as well.
Our (132044) 7.5hp 3450rpm motor with a new pulley, will save you hundreds of dollars versus an American made 7.5hp 1725rpm motor.... we have magnetic starters too.......call me with any questions you may have........Contact Jake at 678-314-6470
 
 
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