Did I spend too much on this motor? (3 Ph Discussion and Shenanigans)

D

Don Nguyen

Joined
Oct 4, 2011
Messages
1,043
New Questions (3/22/2012)

Ok, just in this single purchase of the motor, I have learned more in one day than I did in one year.

That brings me to some new questions:

-If I want to run a Single Phase AC motor, I don't need anything more to run it, right? Just plug it in a go (assuming "normal" conditions).
-If I want to run a Three Phase AC motor, I need three phase power, either by a converter or VFD.
-If I want to run a Permanent Magnet DC motor, then I need DC power, either by a DC controller or voltage converter, right?

-----

Original Post


554767_10150647715623051_688303050_9303134_2125959706_n.jpg

559956_10150647716988051_688303050_9303135_667615053_n.jpg


$100

I mean, I probably can't just plug it in my garage and start using it, can I?

It's kind of big and heavy.
 
Last edited:
You know it is a 3 phase right?
 
7.5 horsepower? that is a really powerful motor. I would hold onto it until you can get a VFD, and then use it. that won't bog for anything.
 
You would need more than a VFD. You would also need a phase converter and more than 110v in your shop. It would be good on a press but way overkill on a grinder.
Jason
 
That is a good deal for a three phase motor that size. You will need a phase converter to run in your shop. You could build a very good hydraulic press with it.
 
Too big for a belt but perfect for a press. You paid way to much though, I'll take it off your hands for $150 :D
 
I'd run a 2x72 on that motor! Why not? Would be awesome on a pwoerhammer too. I would use that specific motor FOR a phas converter, then score another 3 phase in the 3 horsepower range.
 
The guy was selling two other 3ph 5hp motors for about the same price. Maybe I should get back to him?!

I dunno, I was thinking maybe I could sell this for a bit more than I bought it and use the money to contribute to my upcoming grinder.

EDIT: As much as the money is tempting me, I think I will keep it for future use, or if I can find another really cheap 3ph motor I will use this 7.5hp as a converter (as Sam recommended).
 
Last edited:
I noticed it's not a TEFC, so not really suitable for a grinder. It says OFGB if I read it correctly.
 
Yup not a fan cooled motor. Need to watch the op time. You can get a good 10hp phase converter for $735 delivered. I have one and since it comes with the cap starter pack well worth the investment. Mine easily runs all my motors. They suggest you run 1/2 the hp of the converter. However if it is a no load start a 7.5 would run just fine. The company is great also, they have a killer warranty and stand by their product. If I had to do it over again I would have purchased this unit many years earlier. If anyone would like the info please PM or email me and I will send the co information. I have no affiliation with this co, just a very satisfied customer.
 
You could power five KMG's running simultaneously off of a common line-shaft powered by that motor! Just think how convenient that would be!
 
It is a 3 phase motor, which requires 3 phase power, and isn't available at homes and whatnot. So one option would be to get a phase converter that provides 3 phase power from single phase. I'm not sure about the VFD, looking forward to answers on that.



I don't think I'll be using it any time soon. I'll probably keep it for later use as a converter, or maybe hook it up (via belt) to a grinder from an enclosed area :)
 
But a VFD works as both a phase converter and a speed control for 3 phase motors....hence my question.

Due to the size of the motor?
 
You must log in or register to reply here.
Back
Top