220 v 3phase convert?

[nomadskidoo]

I 'm interested in converting a 3 Phase 220 volt 3 hp motor to 1 phase 220v.I know there's phase converters($200),and maybe a 400mf Capasitor but want to be safe in converting,any help,thanks!

 

[wyliesdiesels]

Well you can't convert the motor without rewinding it, but you could buy a phase converter such as a rotary phase converter or a VFD

 

[My Old Tools]

Unless it's a big motor, over 3 HP, its probably cheaper to just swap out the motor. If you are like me and have several 3 phase machines, get a good rotary phase converter. It the machine will benefit from variable speed control, then a VFD is a good option.

 

[Bert_]

I've seen people make them work sort of well with just capacitors, likely won't get full power out of it. It's generally not a good option. Even a rewinding can't make it run on single phase.

What size is the motor and what does it power?

 

[nomadskidoo]

It's right at 3 HP/1,800rpm I heard about adding a 1 leg of just 400mf capasitor to work(I know I spell words wrong).Thanks!

 

[Bert_]

The capacitor value is very dependent on the size of the motor and also how much load is on it. That's part of why it doesn't work very well. Even under good conditions expect only 60% power output from the motor. I have no idea if 400uF would even work.

What is the motor running?

 

[larry_g]

Are you trying to make a phase converter to use single phase 240v, household power, to run a 3 phase machine? Or are you doing something else?

Sounds to me like your trying to make a Rotary Phase Converter.

lg
no neat sig line

 

[nomadskidoo]

"Larry":I'm just trying to run a 3hp 3 phase motor,off of a 220 volt 100amp service supply.I 'v e known, about phase converters,.I know were to buy "Phase Converters".Just if anyone has a better idea?It's a long Winter

 

[anythingyoucanimagine]

Anything is possible but one thing I've learned is that most often you end up spending same/more money with a DIY solution than had you just bought the right thing to begin with.


I realize I'm new here. I have 208Y at my home so have a decent amount of experience with all kinds of fun stuff. As wyliesdiesels said, you can't convert the motor without rewinding it. It is not possible --but you can get a 3hp 220V split phase motor from Horrible Freight for $169 (before coupon).

What are you running with the motor? Is it highly specific or can you swap it out with something else?

Cheers.

 

[Norcal]

Anything is possible but one thing I've learned is that most often you end up spending same/more money with a DIY solution than had you just bought the right thing to begin with.


I realize I'm new here. I have 208Y at my home so have a decent amount of experience with all kinds of fun stuff. As wyliesdiesels said, you can't convert the motor without rewinding it. It is not possible --but you can get a 3hp 220V split phase motor from Horrible Freight for $169 (before coupon).

What are you running with the motor? Is it highly specific or can you swap it out with something else?

Cheers.

A split phase motor is usually fractional HP, for 3 HP & smaller single phase input VFD's are reasonable & a good choice, and if the motor happens to be special or proprietary model, no motor, no machine.

 

[matt_i]

You can build a static phase converter (e.g. get the motor running and have approx 2/3 of available HP...great for saws, mills and lathes, bad for air compressors). You need a dry capacitor 100 microfarads per HP. You need a heavy duty 1 pole switch, I would use a 30A rated toggle switch, in addition to whatever method you use to start the motor normally, which would be a 2 pole (drum switch, contactor, toggle switch, etc) device.

Wire 2 poles of 240vac to the motor leads (configure for low voltage in a 9-wire motor). Wire either of those poles to the toggle, to one pole of the capacitor, other pole of capacitor goes to 3rd phase on the motor.

So you switch the 2 poles of 240vac 1 phase to the motor, it will sit there and hum with a locked rotor. Without delay go switch ON the toggle to engage the capacitor and the motor will magically start. As soon as its at speed (like 1 second) then switch OFF the toggle and the motor will run until you shut off the 2 poles. Repeat for every subsequent start event.

 

[wyliesdiesels]

Have to be careful with this as the motor could overheat since it is single phasing.

Better to get a VFD or RPC.

 

[blazemaster83]

For that size motor I would just look for a single phase motor in the same size and ditch the 3 phase motor. However, if you need the motor to be reversing it's hard to beat 3 phase. You could also try a vfd, that would be my second choice.

Getting into a rotary phase converter can be expensive, I would only go that route if you plan to run more 3 phase motors in the future.

 

[nomadskidoo]

Thanks for the input!I'll start looking for a motor,but I've got another 3 phase motor so might think about a convertor also.

 

[OneOfEm]

A VFD is often less expensive than a replacement motor, and it can add features such as soft-start/stop and variable speed that can be advantageous with some machines.

VFD's don't start getting real expensive until the 5HP range.

 

[nomadskidoo]

Thanks again!I'm looking at the 3 phase convertor,good choice.This unit's like a 1948 by seriall#3/48 so finding a motor could be tuff.

 

[Bert_]

You can build a static phase converter (e.g. get the motor running and have approx 2/3 of available HP...great for saws, mills and lathes, bad for air compressors). You need a dry capacitor 100 microfarads per HP. You need a heavy duty 1 pole switch, I would use a 30A rated toggle switch, in addition to whatever method you use to start the motor normally, which would be a 2 pole (drum switch, contactor, toggle switch, etc) device.

Wire 2 poles of 240vac to the motor leads (configure for low voltage in a 9-wire motor). Wire either of those poles to the toggle, to one pole of the capacitor, other pole of capacitor goes to 3rd phase on the motor.

So you switch the 2 poles of 240vac 1 phase to the motor, it will sit there and hum with a locked rotor. Without delay go switch ON the toggle to engage the capacitor and the motor will magically start. As soon as its at speed (like 1 second) then switch OFF the toggle and the motor will run until you shut off the 2 poles. Repeat for every subsequent start event.

Lots of room to make startup simpler here. Use a momentary start and stop. The start can both make a latching circuit and engage the start capacitor, with a separate contact, as long as you hold the button.

I think I would also experiment with a run capacitor.

 

[mikegt4]

I have Teco VFD's on my lathe and mill, both have worked flawlessly for many years.

https://dealerselectric.com/230V-th...gnsScTree=&gnsTid=43927&SortBy=&GdPageSize=20

 

[Norcal]

I have Teco VFD's on my lathe and mill, both have worked flawlessly for many years.

https://dealerselectric.com/230V-th...gnsScTree=&gnsTid=43927&SortBy=&GdPageSize=20

I have used that vendor a couple of times & have been pleased.

 

[nomadskidoo]

Mikegt4; I'll try that Thanks !

 

[mikegt4]

When ordering it is important that the volts and phase in, volts and phase out and the motor hp all match what you need. They can help you select a VFD that will work for you, in fact it might be better to call them and tell them about your project. Start up current and duration under load might skew the requirements.

 

[rvieceli]

I'm running a couple of Teco FM 50 vfds in the shop and have been pleased.

I use factorymation.com

https://www.factorymation.com/ac_drives_qs/FM50_Series