3 phase question

[Dave Bureau]

I'm looking at a 3 phase planer. one 7.5 hp motor for the head and one 5 hp motor for the drive. my ? is. will one phase converter run both motors, what is the best type to use, and what size should i use.
Thanks
Dave

[Rick Christopherson]

Yes, a single rotary converter will run both motors. Size the converter according to the head motor (largest motor), and it will operate both motors.

If you wanted to get creative on a budget, you could make a balanced static converter (not the store bought kind) for the head motor, and let the feed motor leach off of this as though it was a rotary.

Building a Phase Converter (http://waterfront-woods.home.att.net/Articles/phaseconverter.htm)

[Mike Heidrick]

do you think that set up will run a planer with 2 motors. 1, 7.5 hp for the head and 1, 5 hp for the drive. other than getting a larger vfd. I know nothing about these.
Dave

First off - RICK is the man and knows his converters!!!

3hp is about the max you can get that still has single phase 230V input and 3phase output. After that they are 3 phase in and out.

You need a rotary phase converter. Get yourself a 10 hp one and you will be completely done. It will run both motors at full speed perfectly and can even run another as well if you get say a 3phase DC.

R.P.C.Man at practicalmachinist dot com I believe sells them and is a HUGE resource about them as well. He can help you size it.

Good luck.

[Bruce Boone]

I have a solid state digital phase converter for my CNC machines after having used a rotary phase converter for years. www.phaseperfect.com (http://www.phaseperfect.com) The power is SO much more balanced and doesn't bog no matter how many machines you start at the same time. They are more expensive, but are well worth the cost.

[Bernhard Lampert]

Rotary phase converter is the way to go for those loads. I have a RPC. Just remember that you will be powering a 'hard' load '(high start up current, high start up load). Do not skimp of the idler motor. When you are shopping around be wary of 'hp' ratings, rather compare NEMA frame sizes. The NEMA frame size is a defined, official designation and can't be manipulated by the seller to its advantage. Some of the cheaper RPCs claim hp ratings that are just too good to be true and may be peak hp ratings attainable for a fraction of a second. Looking at the frame size it is easily seen that the hp rating may be fantasy.
Also, may want to look in a remote control start (x-10 based or something like that). Very convenient.
Cheers,
Bernhard

[Dave Bureau]

all this is new to me and dont know anything about it. ebay has some phase converters on there. is the 10 hp unit the one i would need? and would i need anything else?
Dave

[Bernhard Lampert]

Dave,

How about checking Kay Industries and PhaseMatic websites (I have no connection to either one, just use their products), both are reputable companies with a track record and a bunch of good information on their websites. Both have selection tables on sizing the RPC along with the NEMA frame size of the idler. That way you can make a better judgement on the ebay stuff. When I looked last for a RPC, a lot of ebay sellers had some unbelievable Hp values listed. An RPC is actually a pretty simple piece of equipment, but size of the idler motor does matter.
Also amp rating of your motor need to be taken in consideration.
BTW, Are you sure that your feed motor is 5hp? Seems way to high.
If interested, pm me and I send you my set up. I run a Kay phase converter with a x-10 remote for all my 3-phase equipment (milling machine, lathe, planer, slider, drill press, wide belt, dust collector, etc).

Cheers,
Bernhard