looking for links on 3 phase power options

[LD1]

If a static converter is used, you have about 2/3 of the motor ratings, if a rotary converter is used, then you have close to 100%,

I starting under load a rotary converter is needed, if no load a static can be used,

a commercial rotary converter is not much more than a shaft less motor with a static converter, to start it,

the static converter acts a start winding on the unused third phase of the motor, it is a set of capacitors and a short timer that charges the motor third winding to start it, (much as a capacitor start single phase motor does),

when the idler motor is running it acts like a rotary transformer, taking the single phase in two windings and then the rotation creates the third phase coming out the motor,

one can make a poor mans starter by taking a larger three phase motor (10 HP in your case wanting 7.5 HP, belt driving a small single phase motor to it for a starter, (one will have to check rotations and all), but apply power to the idler motor and the starter motor and once rotating disengage the starter motor from idler unit, (do not recommend, but once did see a picture old pull rope starter on the idler motor unit to get it rotating),

I would recommend a rotary converter for your shop.

there are plans on the net and if one wants to even what capacitors' are needed to make a static converter or starter,

Excellent explanation.

And for a shop full of equipment, I too would go with the rotary. The VFD's are nice, but for old equipment without sensitive electronics, the only benefit to them is speed control and easy reversing in you want. But to get those benefits, you would need a VFD for EVERY piece of equipment. And they are only somewhat affordable up to ~3HP ones. Which are in the $300 range for no-name ones. Go to 5hp and they typically jump to what you can buy a rotary 10hp for.

One thing to double check though. make sure ALL of your equipment is dual wound motors. IE: 230/460. Cause of any of it is 460 only, you cannot get that with a 230 rotary convertor. You would need a transformer after the rotary. And would likely be cheaper to repower the equipment with a dual voltage 3ph motor.

(and no 3ph dont mean 3 point hitch in this case:laughing

 

[Midniteoyl]

I just bought a few 3 phase tools to haul down to Mississippi. I have a 400 amp circuit breaker box with 3 or 4 220V lines, so I've got power.

But to get 3 phase will cost well north of $30K (I asked).

My most power hungry is the Powermatic 160 planar w/ a 5hp 3phase motor.

But I also bought a jointer, bandsaw, table saw, RAS, and sander so I figure I need to learn about 3 phase and the best way I can implement it.

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The collection

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Sander

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RAS

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Planar

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Table saw

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Jointer

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Bandsaw

So I'm looking for some GOOD links on converters and DIY converters. I figure I'll want at least a 7.5HP system.

I use to work here.. Manager is my BIL... great convertors. Last forever. Give'm a call..

Phase Converter - Phasemaster Rotary 3-Phase Converters and Miniphase static 3-Phase Converters

 

[newbury]

I had planned on getting a 7.5 to 10HP RPC, however prices for a new one range from about $700 to several thousand. From my reading it may be possible to "gang" or run them in serial such that if they are the right type I could get a 7.5hp and later a 5hp and be able to use about 12hp of that.

There is also a lot written about DIY phase converters.

I started this thread asking for online links, I've sat thru many YouTube videos where the guys talk for 10 minutes and don't tell anything about how they built theirs.

So do y'all have any cache of bookmarks?

/edit - I found this one site Rotary Phase Converter selling 10HP for about $700 and kits for less. It actually looks like with a $100 Kit and a $200 (or less) motor I could have a 10HP phase converter.

 

[LD1]

I dont have any good links. But when I was looking into building a RPH with static (capacitor) start, pretty much everything I read said it wasnt an exact science, and that the start and run capacitor sizes vary from motor to motor, and load to load. Just trial and error to get an acceptable amount of voltage variation.

But if you arent going static, making one is simple, find a donor motor that is large enough that 2/3rd's of its nameplate HP equals you largest load, and wire it up, and decide how you want to start it.

 

[Midniteoyl]

Well, the Kay Industries rotary ones have the tightest amount of voltage variance.. Give them a call. John there can explain a lot and dispell many myths.

And, btw, its not simply 'adding capacitors' as there is some internal modification to the rotor too in order to get a good output.

 

[newbury]

Well, the Kay Industries rotary ones have the tightest amount of voltage variance.. Give them a call. John there can explain a lot and dispell many myths.

And, btw, its not simply 'adding capacitors' as there is some internal modification to the rotor too in order to get a good output.

Kay industries looks like they make some very fine machines, but a 10HP looks like it costs way more than all the rest of my equipment. And I don't think my old iron is going to be real picky on voltage variances.

I'm more planning on something in the $800 range or less.

 

[speedbump]

A friend bought a ban saw for cutting meat. It was three phase with IIRC 1.5hp motor. I wired a submersible pump control box to it and that took care of starting the motor and removing the start capacitor from the circuit once the motor started. Worked great, but you only have 2/3rds of the actual horsepower, so you just don't lean on the saw too hard.

 

[Midniteoyl]

A 7.5HP RPC from American Rotary costs less than $800.

This WILL NOT run that Planar.. Kay would call this a '4hp (at most) low end'... Its built on a 7.5hp 213T frame. There is NO WAY you will get 7.5hp out of it. Face it, 3 - phase costs


With out any sales pressure, my BIL has agreed to give advice on sizing and buying one.. No need to buy from him. But, he will tell you which ones to avoid... Lemme know and I will PM you his cell phone number.

 

[newbury]

This WILL NOT run that Planar.. Kay would call this a '4hp (at most) low end'... Its built on a 7.5hp 213T frame. There is NO WAY you will get 7.5hp out of it. Face it, 3 - phase costs


With out any sales pressure, my BIL has agreed to give advice on sizing and buying one.. No need to buy from him. But, he will tell you which ones to avoid... Lemme know and I will PM you his cell phone number.

And a 10HP starts around $850 from American Rotary.

 

[LD1]

Well, the Kay Industries rotary ones have the tightest amount of voltage variance.. Give them a call. John there can explain a lot and dispell many myths.

And, btw, its not simply 'adding capacitors' as there is some internal modification to the rotor too in order to get a good output.

Yep. They typically increase the number of windings on the 3rd leg. Since the first two are created by the power company, and that third is created by induction, there are some losses. More windings helps with that.

This WILL NOT run that Planar.. Kay would call this a '4hp (at most) low end'... Its built on a 7.5hp 213T frame. There is NO WAY you will get 7.5hp out of it. Face it, 3 - phase costs


With out any sales pressure, my BIL has agreed to give advice on sizing and buying one.. No need to buy from him. But, he will tell you which ones to avoid... Lemme know and I will PM you his cell phone number.

In all fairness, they do state that it will handle easy loads up to 5hp, medium loads up to 4hp and hard loads and CNC loads up to 3hp. But yeah, the 7.5hp rating is deceiving. Most RPC are rated at what they can run, NOT rated at what the pony motor is rated for.