VFD or Rotary Phase?? - Scored a Free 15hp 3 phase motor

[Patrick Irish]

I have a Huywang HY04D023B VFD new in box. Bought it new on amazon to power a 5hp 3 phase powermatic 16" planer.....5 months later it's still in the box.

My dad dropped by a free 15hp 3 phase motor and enough 6 gauge wire to do a rotary phase converter. Only thing I'd need to do I buy for the RPC method is a 15hp rated panel to start and stop it. This would allow me push button start the RPC and have a clean wall setup. Plan is to run two new 220v outlets so I can stop using my dryer plug for my table saw as well.

Question:

Which route would be quickest? Preferred? RPC or VFD? I'm leaning to the RPC because I can do more with it and don't have to remove/bypass the switch on the planer. I can also remove it and take it with me when the fiance and I move.

The VFD I'm hesitant because of the parameters/settings and crap manual. I'd likely sell the VFD and get some of my $ back.

[Mike Heidrick]

The rpc that large should ideally be direct wired. The panel will want larger than 6ga most likely. Ideally have that panel power its own 3ph lug only panel. Then the 3ph tools get their own circuit sized correctly for its load.

Let me know on the vfd price. They are handy for vs and reversing tooling applications.

[Carroll Courtney]

Tons of You Tubes on this subject very helpful

[Kevin Jenness]

If you are contemplating more 3 phase equipment in the future, the rpc is the way to go. The planer just needs a power source without the added attractions of a vfd. With a free motor you can add a starter and distribution subpanel cheaply.

For just the single machine, take the vfd and manual to a motor shop or master electrician that does controls and have them program it for $100 or so.

[Curt Harms]

I just installed a TECO-Westinghouse VFD on a drill press. For that application I think a VFD is very handy - variable speed with the turn of a knob, reverse, really low speeds etc. For a planer? You don't really need the 'tricks' a VFD provides and a RPC could power a separate 3 phase panel if you added more (cheap) 3 phase equipment in the future.

[David Kumm]

How much power do you have available? A RPC of that size needs close to 100 amps of single phase power considering the other stuff likely to be run in the shop, lights, fans, etc. Dave

[Patrick Irish]

How much power do you have available? A RPC of that size needs close to 100 amps of single phase power considering the other stuff likely to be run in the shop, lights, fans, etc. Dave

About a 100amp panel.

I did my math and 15hp rpc would need about 60 on initial start up and then drop off. I'll check it out again and see if I'm right.

The planer motor is 5hp 3 phase if that makes a difference. Amp rating on the 5hp planer motor is 12.6.

[Bradley Gray]

I have a 10hp Kay RPC. It is installed on a 60amp single phase breaker as spec'd on the install sheet. The unit will start 10hp and run 20 total IIRC. Your 15 will likely need more like 90amps. Probably cheaper to find a 10hp motor than to upgrade your service.

[Erik Manchester]

About a 100amp panel.

I did my math and 15hp rpc would need about 60 on initial start up and then drop off. I'll check it out again and see if I'm right.

The planer motor is 5hp 3 phase if that makes a difference. Amp rating on the 5hp planer motor is 12.6.

My 15 hp RPC is plated 105A so there may be some variance amongst manufacturers. The VFD will give better power as there is no wild leg to contend with, but as others have said, an RPC makes adding additional machines easy. I use both in my shop as the VFDs offer a host of other useful features in addition to phase conversion.

[Mike Heidrick]

Brad, run 20 total? What does that mean?

[David Kumm]

I also ran a Kay 10 hp and Kay, unlike many other brands, rates its sizes by the largest motor it can start, rather than the total hp that can be run at the same time ( that is the 20 referred to above ). To do that you need at least 60-70 input amps. Amperage limitations would be my concern with a 15 hp motor but the companies that sell the electronics for the rpc should be able to advise if you give them the details of the motor. Typically a 1750 rpm 4 pole motor is the preferred choice. Dave

[Bradley Gray]

Brad, run 20 total? What does that mean?

Dave pretty much covered this. Also, when I installed the 10hp Kay it replaced a homemade 7hp RPC. My 7hp 24" planer has way more power now.

I just checked and the Kay is plated to start 10 and run 30hp