how about this motor.

JTknives

JTknives

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Jun 11, 2006
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the place i have been getting all my scrap tool steel also has motors. i spoted one thats a dayton totaly enclosed and has the fins on the outside. its industrial rated with a service factor of 1.25. its 3hp and 3ph. but the shaft i huge, it starts at like 1.5" and steps down to like 1" would this be a problem. thay onley want 70 bucks for it. it seams very light, are 3ph lighter than 1ph. thanks all. would a VFD be way expensive for this.
 
Jarod
Unless you have three phase power coming into your apartment it will be of no use to you. You need a 2phase motor.
Matt
 
actually you need a single phase motor, or need a 3 phase converter to use it with single phase power (which is what you most likely have) sounds like more work than just to buy a good single phase motor from suprluscenter.com, or someplace like it...
 
Isn't 220v two phase (I got into this argument with a contractor)? - You get two hots and a ground/neutral from the electric company. The two hots are out of phase - in other words - two phase. If they weren't out of phase (in respect with eachother), the voltage measured between the two would be zero. Instead, the voltage measured between the two hots is 220. This is because at the moment that one hot is peaking at +110V, the other hot is at -110V. Right?

Anyway, if you want a 3 phase motor, I got one for free - you just pay shipping.
 
realy. what hp is it?

with 3ph 2 phases are 180º apart and the last one is 90º apart from the other 2. thats why to change rotation direction you just swap any 2 wires. 220 is not 2 ph because its created by a transformer and hots just switch. 120 is just one hot and the center tap of the transformers secountdary winding. A VFD is a varyabull frencey drive. it turnes 220 1ph into 220 3ph with a twist. it alowes you to change the HZ per sec thus alowing speed controll from nothing to full.
 
Pat,

I never really thought about it like that, but yes, I suppose you might think of the two 180 deg legs as "2 phase". But no, this is what people are talking about as single phase. One leg to ground is 120, two legs of "single phase" 180 out of phase is 240. In electricians nomenclature anyway...

Jarod,

There have been more than one standard of three phase in this country, so perhaps there exists a service somewhere with 180 and 90 degree legs. But around here all three legs are 120 deg out of phase. The voltage between any leg and neutral is 125 volt and between any two legs is 208 (not 250). You actually can run single phase two leg equipment with this cattywupus 208.


I got an electric motor joke for yall:

A little single phase motor looks up to a big three phase motor and says "how come you have four wires going to ya, but I only have three?" And the big motor says "don't worry, thats just a phase going through you"

(get it, funny play on words...)
 
Nathan, that sounds like the kind of jokes I tell. You should be ashamed, I usually am.:D


Mike
 
Actually, with 3 phase, each phase is 120 degrees out of phase with respect to the other two. When you connect something to just two of the three legs, you get single phase. This is because each phase acts as the neutral for the other, and 240V is also still single phase even though you have 2 hot wires. You can not get 2 phase here in the USA. Some country's utility companies do provide 2 phase, but it is brought in on 4 wires.
 
Jonx said:
Actually, with 3 phase, each phase is 120 degrees out of phase with respect to the other two. When you connect something to just two of the three legs, you get single phase. This is because each phase acts as the neutral for the other, and 240V is also still single phase even though you have 2 hot wires. You can not get 2 phase here in the USA. Some country's utility companies do provide 2 phase, but it is brought in on 4 wires.
Click to expand...


I'll be damned...
 
Jonx said:
Actually, with 3 phase, each phase is 120 degrees out of phase with respect to the other two. When you connect something to just two of the three legs, you get single phase.
Click to expand...

Hence, when you lose a leg on a 3 phase motor the motor is said to be "single phasing" - often due to a blown fuse, and the remaining 2 legs will either pop their overloads or blow their fuses due to the resulting overcurrent condition.
 
it seams very light, are 3ph lighter than 1ph.
Click to expand...

Generally speaking, yes, 3ph motors are physically smaller than a comparitable 1ph motor. They are also more efficient, and tend to last a lot longer.
 
Jt,

before you buy a 3ph motor you really need to see it work or have a DOA guarantee. Also make sure it will run on 220 or 208v. Some only run on 480V+. You can find a good 3ph motor on ebay for around $100 NIB and with DOA guarantee. i have too many now, just waiting for the next machine I build. Bought 6, 1hp-5hp and none were over $150. Shipping on that 5hp was killer though. Shaft size will only be a problem if you need a 5/8 for mating purposes. There are collars that will adapt these but run out can be a problem. Or you can turn down the shaft at your new job. They probably have a lathe or 2?

Chuck
 
Thanks for the info, guys. I'm still confused.

Anyway, to answer your question J-Rod, I don't know the HP (hows that for an answer).

Its the motor to an OLD Wilton Square-Wheel Belt Grinder (love that name - "square wheel"). So I'd assume its somewhere in the 1 to 2 HP range. Maybe the faceplate is burried somewhere under that dust.

My offer (although serious) was somewhat of a joke - you'd probably pay almost as much for shipping my motor as you would for the motor at your scrapyard.
 
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