Horsepower of a Powermatic Mortiser?

[Wade Lippman]

They say there are no stupid questions, but I think I have one.

My new toy is arriving Wednesday. It is 15a, 0.75hp. The rule of thumb I have always used is 1hp = 10a 120v. I know some motors are more efficient than others, but most are close to that. Does Powermatic use an extremely inefficient motor or what?

I guess I have a related question. Most 3hp motors are 15A 240v. The 3hp on my Grizzly cyclone is 22A. Mine is 12 years old, but I just looked and the new ones are the same. Again, why?

[Carroll Courtney]

I don’t own one, but I am envious. I be willing to bet that it’s not Baldor or any other American made motor. But regardless of motor have some fun by putting it to work.

[Kent A Bathurst]

My guess is that they are telling the owner that they need a 15a circuit to run it. In other words, it doesn't need a 20 a, so that investment is not required to run the machine.

I had the 1hp 719, and IIRC it was plugged into 15a circuit as well.

[Bill Dufour]

I have always used 12 amps as a rule of thumb. Looked it up just now and read 13-16 amps FLA.
Bill D

[Wade Lippman]

$600 at Lowes. I had a 10% off coupon, gift cards that cost 85% and 5% Capital One rebate. It was almost free.

[Rod Sheridan]

They say there are no stupid questions, but I think I have one.

My new toy is arriving Wednesday. It is 15a, 0.75hp. The rule of thumb I have always used is 1hp = 10a 120v. I know some motors are more efficient than others, but most are close to that. Does Powermatic use an extremely inefficient motor or what?

I guess I have a related question. Most 3hp motors are 15A 240v. The 3hp on my Grizzly cyclone is 22A. Mine is 12 years old, but I just looked and the new ones are the same. Again, why?

Efficiency and power factor.

A high quality 3HP motor will be in the 12 to 13 ampere range, 240V single phase.

Motors with extremely high current are generally very low power factor motors, perhaps as low as 0.5.

A capacitor run motor can be as high as 0.99 PF.

Regards, Rod

[Wade Lippman]

Are you saying these motors have a very low power factor? Is there an advantage to that, and if not, why would they use them?
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I may have the answer. Someone at Amazon says the motorplate says 7.8a. That makes sense. So why does Powermatic claim 15a? Circuit size?


That is not true for the Grizzly Cyclone. They claim 22a, but specify 40a for the circuit.

[Rod Sheridan]

Are you saying these motors have a very low power factor? Is there an advantage to that, and if not, why would they use them?
----------------------
I may have the answer. Someone at Amazon says the motorplate says 7.8a. That makes sense. So why does Powermatic claim 15a? Circuit size?


That is not true for the Grizzly Cyclone. They claim 22a, but specify 40a for the circuit.

Hi Wade, yes there’s an advantage to low power factor motors for the manufacturer, they cost less.

For users, low power factor is a disadvantage for distribution requirements

Regards, Rod

[Keegan Shields]

Some machines are harder starting than others and require more amperage draw initially. I believe dust collectors are in that category. That may be why Grizzly recommends a 40a circuit.

Low PF motors are cheaper...

[Jeff Roltgen]

FWIW: I have the floor standing model # 719T, if that's the model you bought? Year of mfg: 2014. The motor plate shows 1HP rating 11amps at 110V / 5.5 amps at 230V