Should I Buy This 10HP Motor?

[CaptDon]

Every question you have posted shows this isn't a project for you. Go figure, if a kwh is 12.8 cents, and your
motor is about 10KW then it cost 128 cents per hour. You probably don't have 3 phase anywhere near you
and if you do you will need to determine if it is 208Y or 240 Delta with a wild leg, all questions we can't answer
for you. Is Canada standardized on 50 or 60hz? Doesn't matter if you use a VFD. Gearing down through the
attached gearbox and then gearing back up is a piss poor idea and very wasteful. Use the small motors if you
ever figure out the voltage and wiring on them for each individual project. Maybe just go to harbor freight and
by the machines you think you need, you'll be less likely to kill yourself or blow up the earth in the process.

[james_s]

That's a single phase motor, it is not suitable for use with a VFD. If you wire it for 240V it will draw half as much current as it does from 120V so if you have 240V available then that is the superior option as you can use thinner wire and the voltage drop will be lower due to the lower current. There will be no significant difference in performance either way though as long as it it is wired adequately. The wiring looks pretty straightforward, just follow the diagram. If you wire it up as shown for low voltage with a standard 120V power cord and plug it in it should start up. I suggest plugging it into a power strip that has a breaker on it and flip the switch rather than just plugging it straight into the wall, that's less likely to result in fireworks if you get it wrong.

As for the other stuff, that mostly looks like junk unless you happen to need some particular fitting, it's mostly domestic plumbing stuff. I see a thermostatic expansion valve (TXV) that looks like it's from a central air conditioning system, probably a bad one that was replaced.

[electromateria]

That's a single phase motor, it is not suitable for use with a VFD. If you wire it for 240V it will draw half as much current as it does from 120V so if you have 240V available then that is the superior option as you can use thinner wire and the voltage drop will be lower due to the lower current. There will be no significant difference in performance either way though as long as it it is wired adequately. The wiring looks pretty straightforward, just follow the diagram. If you wire it up as shown for low voltage with a standard 120V power cord and plug it in it should start up. I suggest plugging it into a power strip that has a breaker on it and flip the switch rather than just plugging it straight into the wall, that's less likely to result in fireworks if you get it wrong.

As for the other stuff, that mostly looks like junk unless you happen to need some particular fitting, it's mostly domestic plumbing stuff. I see a thermostatic expansion valve (TXV) that looks like it's from a central air conditioning system, probably a bad one that was replaced.

Ok thanks! I think I'll wait for help on Saturday to wire up the motor, just to be 100% sure I do it correctly.

Every question you have posted shows this isn't a project for you. Go figure, if a kwh is 12.8 cents, and your
motor is about 10KW then it cost 128 cents per hour. You probably don't have 3 phase anywhere near you
and if you do you will need to determine if it is 208Y or 240 Delta with a wild leg, all questions we can't answer
for you. Is Canada standardized on 50 or 60hz? Doesn't matter if you use a VFD. Gearing down through the
attached gearbox and then gearing back up is a piss poor idea and very wasteful. Use the small motors if you
ever figure out the voltage and wiring on them for each individual project. Maybe just go to harbor freight and
by the machines you think you need, you'll be less likely to kill yourself or blow up the earth in the process.

Most motors don't come with a gearbox like the original 10 HP one I inquired about. If there's a gearbox I could just remove it then attach a different setup.

I'll ask my brother in law on Saturday, he wires up and programs industrial motor setups for huge sawmills. I heard that if you don't have 3 phase power there's a way to "simulate" it. Is that not true? I'm going to do some serious research on 3 phase tonight if I have time.

Buy from harbor freight? That's the cowards way out lol. I want a beast industrial motor in my workshop.. and I demand satisfaction

[bdunham7]

Most motors don't come with a gearbox like the original 10 HP one I inquired about. If there's a gearbox I could just remove it then attach a different setup.

I'll ask my brother in law on Saturday, he wires up and programs industrial motor setups for huge sawmills. I heard that if you don't have 3 phase power there's a way to "simulate" it. Is that not true? I'm going to do some serious research on 3 phase tonight if I have time.

Buy from harbor freight? That's the cowards way out lol. I want a beast industrial motor in my workshop.. and I demand satisfaction

You can wire up some capacitors to get a three-phase motor to run on single phase, but it is a crap solution and your motor will have reduced power, reduced efficiency, a terrible torque curve and will probably burn out in short order if you try to use it with any significant load.  If you want  a variable-speed motor, an appropriate 3-phase motor and a VFD is the way to go.  If you don't need variable speed, single phase motors are just fine up to 3HP or so, above that you need to worry about a few more things like wiring.

The problem with just picking up random motors is that you don't know enough about them.  Induction motors can be configured (by rotor resistance and winding design and more) in many different ways depending on their application--they can have torque curves that vary from operating only near synchronous speed--like a bench grinder--with a high breakdown speed (the slip percentage where the torque starts decreasing) of 90% all the way to a motor that produces peak torque from zero RPM.  This applies to 3-phase as well as single phase capacitor start/capacitor run motors.  3 phase does not automagically mean infinite starting torque, which some people seem to believe.  The advantage of using a 3-phase with a VFD is that you can control speed and in the case where you have a large inertial load, like a very large grinder, you can soft-start it and not overheat the motor.  Not burning up is a different issue than having a lot of torque.  Motors for a water pumps, bench grinders, table saws and air compressors are all specifically designed for those applications.  A PSC motor designed for a fan or fluid pump may totally fail at starting a heavy inertial load.  A motor designed for zero-speed starting torque, like some conveyor systems, may be very inefficient and slow if you use it in a saw application.  You can't just randomly mix and match and the fact that some motor is a 'beast' doesn't mean it will work for you.

[james_s]

There are a few different ways to create 3 phase power. The easiest and best way is to use a VFD. The other method that was commonly used in home shops back when VFDs were still very expensive is a rotary phase converter. This was similar to a big 3 phase motor, sometimes people used an actual 3 phase motor to build one but you could also buy them ready made and they looked like a motor with no output shaft. You would add some appropriate capacitors to create a phase shift and then get the thing going, some used a small single phase "pony motor" to spin the thing up, then once it was running it would generate 3 phase power across the windings from a single phase input. It worked, but you had to be careful with load balancing, and it would take a big motor, like 7-10 HP to get enough 3 phase power to run a 3-5HP motor on the machine you wanted to power.

I think everyone just uses VFDs now, they're superior in every way to a rotary converter.

It's true that motors are optimized for various tasks, however quite a few are designed to be fairly universal. The main thing you have to watch out for is motors designed for fans or blowers typically do not have a built in cooling fan as they are designed to operate within the air stream of the fan they are driving. The next biggest difference is starting torque, motors designed to power air compressors for example are typically capacitor start, capacitor run types (they'll usually have two humps on the top for the capacitor housings) but that doesn't apply to 3 phase. There's a first time for everything but I have not yet burned up a 3 phase induction motor by repurposing a random motor for some other application.

[electromateria]

There are a few different ways to create 3 phase power. The easiest and best way is to use a VFD. The other method that was commonly used in home shops back when VFDs were still very expensive is a rotary phase converter. This was similar to a big 3 phase motor, sometimes people used an actual 3 phase motor to build one but you could also buy them ready made and they looked like a motor with no output shaft. You would add some appropriate capacitors to create a phase shift and then get the thing going, some used a small single phase "pony motor" to spin the thing up, then once it was running it would generate 3 phase power across the windings from a single phase input. It worked, but you had to be careful with load balancing, and it would take a big motor, like 7-10 HP to get enough 3 phase power to run a 3-5HP motor on the machine you wanted to power.

I think everyone just uses VFDs now, they're superior in every way to a rotary converter.

It's true that motors are optimized for various tasks, however quite a few are designed to be fairly universal. The main thing you have to watch out for is motors designed for fans or blowers typically do not have a built in cooling fan as they are designed to operate within the air stream of the fan they are driving. The next biggest difference is starting torque, motors designed to power air compressors for example are typically capacitor start, capacitor run types (they'll usually have two humps on the top for the capacitor housings) but that doesn't apply to 3 phase. There's a first time for everything but I have not yet burned up a 3 phase induction motor by repurposing a random motor for some other application.

Really cool!! I just spent some time researching the rotary converter. I still don't fully understand how it works, but I find it really interesting! I'm going to do more reading on it tomorrow.

Theoretically - say I were to stick 3 plugs into a power supply, then direct those "three random / uncontrolled phases" to a control unit that syncs up the cycles, wouldn't that output some kind of 3 phase power? In my mind it makes sense lol.

Lots of motors call for 480 VAC, my outlet only puts out 120v / 240v. Does the VFD boost up the voltage too?

What's a "3rd leg" / "third leg of power"? Are those just other ways to say three phase power?

[Berni]

A rotary converter is simply using a motor of one type to spin a generator of a different type to create a different kind of power.

These used to be used a lot in the old days before power electronics became practical. They even used them for DC power supplies to turn say 3 phase AC power into 10V DC power at many kilowatts.

The trick is that in some cases the motor itself can be used as a generator simultaneously, as is the case for single phase to threephase conversion. 1 of the 3 windings is used to spin the motor while the other 2 windings act as generators to create the other two missing phases. This is because you can run a 3 phase motor on single phase by first spinning it up by hand and then applying power while its spinning. The performance is of course much reduced but it works.

[Renate]

This is because you can run a 3 phase motor on single phase by first spinning it up by hand and then applying power while its spinning.

Well, yeah, that was the phase converter/inverter aka rotary converter I was referring to.
Of course they throw a cap on it so it can start by itself.

We had a machine shop that ran off single phase converted to three phase.
You'd start the converter, then start a shop tool.
You could even turn off the converter at that point.
After that you could even start another shop tool because the first tool is being a converter all by itself.
(Of course the torque is not the same.)

I had an electric lawnmower that the capacitor died.
You'd turn the mower on its side, kick the blade, then switch the power on.
No, this is not recommended by the Safety Institute.