jas67
Platinum Member
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
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