Electrical question follow-up

[Julio Navarro]

Ok, I returned my bad HF 5hp motor to HF and they refunded my money so I drove down the road to Northern Tool and bought the Leeson 5(SPL)hp 230V motor listed below:

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200306767_200306767&issearch=162493

I am a bit confused, though. I dont know what the 5(SPL)hp means. I know it stands for split phase but how does that effect the hp and did I actually get a 5hp motor?

Do I need to wire a split phase motor differently? I bough the display model so there are no instructions, etc.

I feel more confident with this motor than the HF one.

Thanks for all your helps

[Kyle Kraft]

I thought it meant "special". My air compressor motor has only the letters SPL in the horsepower box on the nameplate. I always thought it was to help prevent the OEM from having to answer the uncomfortable questions which may arise when the buyer compared the horsepower stated by the mfgr. and the motor nameplate horsepower. I did the Ohms law calculation and found my 3.5hp compressor actually has a 2hp motor on it. When I questioned the mfgr on this they stated that the air stored in the tank could create 3.5hp worth of work. I responded with a gasp and stated, "You mean I bought an energy machine in which the output exceeds the input?".

[Julio Navarro]

...When I questioned the mfgr on this they stated that the air stored in the tank could create 3.5hp worth of work. I responded with a gasp and stated, "You mean I bought an energy machine in which the output exceeds the input?".

NOW that IS special!!

[Howard Acheson]

You are correct Kyle. The "SPL" means Special which is code for it doesn't really produce 5 hp. It's a designation that motor manufacturers started using on consumer grade compressors. It's basically the same as Sears using "Peak Horse Power" on their tools. Because compressor manufacturers started marketing their products using horsepower as a measurement, they had to get the motor manufacturers to stop putting the generally accepted horsepower on the label. For induction motors, the accepted rating is "continuous power". Using that rating, a 5 hp compressor really would have a 2-3 horsepower motor. Of course that conflicted with what the compressor manufacturer was selling so the motor guys caved in and started putting "SPL" in the HP block of the label. A 15 amp 230 volt motor is 2-3 hp.

All this came out a few years ago when the compressor manufacturers were sued for false representation.

If the motor is going to replace a compressor motor, then it's fine. However, if it is to be used for something else that requires a real 5 hp motor, he's got the wrong thing.

[Julio Navarro]

so can I assume I at least have a good 3hp motor?

[Jim O'Dell]

Julio, look at Bill Pentz's site on the Leeson motor. He claims it is an actual 3 hp unit, but is 5hp compressor rated. Also, go to the Leeson website, it should give you all the information you need. And my new Leeson I got from Clear Vue with my cyclone didn't have an owner's manual...so I doubt one exists. Jim.

[Pete Bradley]

The motor that you have doesn't look like the motor in the picture, am I right?

A split phase motor is the cheapest design of the typical A/C induction motors. However, it has relatively low starting torque and high starting current. Also, this is a compressor-duty motor so it was designed to stop and cool off regularly. If you're putting it on a compressor, you're good, but it wouldn't be a great choice on many other machines.

Finally, this is not a true 5HP motor. With those specs you're probably getting about 2.

This is not to say it's a bad motor, it's fine for some applications.

You can learn more about the different types of motor at:

http://www.iprocessmart.com/leeson/leeson_singlephase_article.htm

Pete

[chris del]

A true 5hp @ 230v draws between 21 and 24 amps, if it was possible to wire @ 115v you would be looking at 40-50 amps.
If you have a 5hp compressor (as I do) and run it @ 115v on a standard 15 am circuit in all likelyhood you are drawing approx 12 amps, maybe closer to 15 on startup. This would more accurately represent about 1.5 true HP......
I may be wrong, but I believe that when it comes to belt driven compressors, the hp rating is that of the actuall drive after reduction.
If you had a 3:1 reduction on the belt drive you would in theory increase you torque x 3. Making a 1.5hp motor into a 4.5hp drive.

[Pete Bradley]

I may be wrong, but I believe that when it comes to belt driven compressors, the hp rating is that of the actuall drive after reduction.
If you had a 3:1 reduction on the belt drive you would in theory increase you torque x 3. Making a 1.5hp motor into a 4.5hp drive.
It doesn't work that way. HP is directly proportional to Torque*RPM. You don't get more HP by gearing down, you just trade RPM for torque.


Pete

[chris del]

Pete,
I was just tring to explain in understandable terms...

What I meant was your would be getting the amount of torque equivelent to a 5hp after the reduction.

Hp x 63000 / rpm = in/lbs torque

[Don Baer]

Julio,
The motor you have is probubly around 3 HP not know in the losses in the motor It's hard to tell exactly But here is how you can rate the comtinuous HP of any motor.

HP = Volts x Continuous amps/ 746 (Convert watts to HP) x effecncy.

Assuming 30% losses due to copper losses, windage, friction and depending on the air gap between the stator and the rotor you would ge the following.

230 x 15/746 x .7 =3.2 HP

[Julio Navarro]

You've no idea how much I appreciate all your helps.

I've decided to use this motor for a while till I can round up enough cash to get the true 5hp from Ed Morgano (in a week or two) at which time I will try to sell this motor on e**y.

so going on the fact that I have a 3.2hp Leeson I will know what to expect.

Thanks everyone.

[Jim O'Dell]

Julio, I think you'll find that the Leeson from Ed has the same rating. It is a compressor duty 5 hp motor. If this one works for you, there would be no reason to change the motor out. You can follow the link on Ed's and Bill's sites to Leeson, and check the amp draw. Could even ask Leeson about both motors...I bet you will find that they are electrically the same. Just different case and/or mounting. Jim.

[Julio Navarro]

Julio, I think you'll find that the Leeson from Ed has the same rating. It is a compressor duty 5 hp motor. If this one works for you, there would be no reason to change the motor out. You can follow the link on Ed's and Bill's sites to Leeson, and check the amp draw. Could even ask Leeson about both motors...I bet you will find that they are electrically the same. Just different case and/or mounting. Jim.

Jim:
I looked at the leeson motor on their website and the amp draw was about 20, mine is 15 so if amp is evidence of hp I would say my 15 amp has fewer hp than Ed's 20 amp one. I will be watching how much suction this one gets with the 14" impelor before I decide to sell it and get Ed's although I would very much like to give my business to Ed as Bill Pentz gets a bit of a royalty as I understand it. I also like the housing on Ed's.

[Don Baer]

Julio,
Did you invest in a clamp on amp meter. I checked northern Tool and they have one that will work for you. You can also find this a useful tool for other uses in the shop, like checking you planner and jointer etc.

Otherwise your realy wont know what going on with your syste, I wish you were closer, I'd lone you mine.

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200318981_200318981

[Julio Navarro]

Don:

You know, I almost picked one up at HF when I was returning the motor. As I stood in line waiting for the manager to appear to approve the return I glanced at the 19.99 clamp meter, then at the 89.99 motor, then back to the meter, the motor.... Untill I stopped and thought to myself.."What am I thinking!!!"

I think I will pick one up at the local BORG Ive been eyeing one for $80 that I want to get and as soon as I do I am sure I will be right back here asking how to use it:D

[Kent Fitzgerald]

I think I will pick one up at the local BORG Ive been eyeing one for $80 that I want to get and as soon as I do I am sure I will be right back here asking how to use it:D

What, my instructions aren't good enough for you? :p

http://www.sawmillcreek.org/showthread.php?p=415265#post415265

[Julio Navarro]

What, my instructions aren't good enough for you? :p

http://www.sawmillcreek.org/showthread.php?p=415265#post415265
'comming back to ask' was actually a rehtorical question?:o I actually meant "comming back to look at YOUR instructions...yeah thats it,:cool::D:p