Three phase power primer

[Jon Snider]

Are some of you able to help me get up to speed on 3 phase power? I’ve read some articles on Google search and as many as I can find here and at garage journal. The problem is there doesn’t seem to me a consistent preference, although it appears that RPC might be the best.

Mainly interested in best converter choice, plus HP requirements and any tips I should consider while building new shop and wiring it up. The noise of the PC is an issue, from some videos it seems maybe the digital ones are louder?

I’ve found locally a nice Dewalt GE and have had my eyes for a while on a friends Oliver 229 which I might eventually convince him to let go. Plus some day my ship might come in and that elusive Yates Y30 or 20 might just show up on my doorstep.

Not yet sure how im going to sneak the GE into the garage, since the shop isn’t started yet and I’m not going to even consider taking it down temporarily to store in the basement shop. My significant other will probably not be happy. Oh well, in for a penny, in for a pound.


Thx

Jon

[Darcy Warner]

I sat my idler motor outside, noise issue solved. Although it couldn't be heard inside once you turned something on.

[Mike Cutler]

Do you plan to buy more three phased equipment? If so, the RPC is your better long term solution. One machine, and and inverter/VFD might be better as long it can handle the rated HP of the motor.
It's not really a question of "best". It's more a question of end goal use/solution.

[Jon Snider]

Yes, both the planer and Yates saw would be three phase. Plus who knows what happens in the future if I keep going to local auctions and succumb to further “needs”.

[Steve Jenkins]

When I moved my shop and no longer had 3phase I had several machines that needs it so I bought a rotary and fed a 3phase panel with it. I can start 25 hp and run a total of 75. It is inside but the noise is drowned out by anything else that’s running.

[Patrick Irish]

How many HP is the 3 phase machine you want to power? How many other 3 phase machines do you plan to acquire?

I got a 3 phase 5hp powermatic planer and immediately went the VFD route. I'm in a townhouse and my 2 car garage was small for a RPC to be placed. Plus, a 15hp RPC is pretty good size.

I had issues and concerns wiring the VFD and programing it since I bought a chinese version from amazon that has a notoriously bag manual. I was going to scrap it and do a 15hp RPC with panel of capacitors to start it BUT was worried my 90amp panel wouldnt be enough.

I eventually wired the VFD and followed several youtubes and posts and it works great.

When I move to a bigger place and build a decent shop, I'll certainly run an RPC but have the motor outside. It would allow me to find a milling machine and lathe.

Ebay has good deals on RPC panels that will start the 3 phase RPC motor. Often they are wired into a separate breaker box with outlets and looks clean.

[David Kumm]

If you go RPC, you can buy or build the components and add your own idler motor or buy the whole unit. Most complete units are sized such that you need to buy a 7.5-10hp rpc to start a 5 hp motor. Kay units are sized by the largest motor it will start so a 5 hp Kay is about the same as a 7.5-10 hp American rotary. Just be sure you talk to the manufacturers about your needs. The rpc will be balanced for a certain sized load but will work with most machines. A rpc that is balanced for a 10 hp load will be somewhat unbalanced for a 1 hp motor. Think about the range of motors you will need to run. If you have extra cash and want to avoid that or the noise, look at Phase Perfect. The 10 hp unit will start a 10 hp motor and run 30 amps on the output size. The output is balanced for all motors and there is very little sound. An equivelent rpc costs about half but those of us with the PP would not go back. Dave

[Jon Snider]

Thx so far. Spent some time talking to the rep at American Rotary. I’m not sure I’m much further along, frankly, but understand now I need to determine how much single phase power is left to supply the house main panel, or see if I can get a secondary power feed from the city to the shop.

For now, what I’m trying to find out is what needs to be done for planning and wiring before floor sheathing goes on joists or walls go up.

Jon

[Jim Becker]

Jon, "sometimes" the right solution is to convert the machine to single phase, such as a 5hp motor when your use and expectations can be served by that. That can be the case when the available supply isn't sufficient to handle the load of both a converter and the machines that need to run simultaneously. A VFD on the individual machines is sometimes an alternative, too, depending on the horsepower requirements. Consider all your options!

[Mike Heidrick]

To be prepared: Get enough service to shop (200amp) so you can run a decent rpc (100 amp available. Bringing in 400 amp to the house and wiring house for 200 and shop for 200 is what I did. I have a 100 amp circuit feeding my rpc that feeds a lug only 3ph panel. In walls I have various dedicated 3ph circuits from that 3ph box. My panels are mounted external but the wall circuiys are all in wall wired. I have low voltage controls switching on the rpc and stations around the shop to do that by the 3ph wall outlets. Plan your tool circuits accordingly. Lots of big tools like large dc and large sanders are also 3ph.

[Bill Dufour]

You can run that GE on a 3hp VFD. It will only top out at 3hp but that will be enough for most people.
Bill D

[Steve Rozmiarek]

Any chance you have a three phase line to your property already? You might be able to get a service added for cheaper and a heck of a lot easier if you do. Some utilities charge ridiculously for this, some don't.

[Jim Becker]

One easy way to tell if three phase is nearby...a pole with three transformers ringed around it with drops from each of the high-voltage lines to individual transformers. Rare in residential areas, however.

[Alex Zeller]

My neighbor is a woodworker by trade and buys a lot of used industrial equipment. He has one large RPC for his whole shop but found that going with a VFD was a better option for several of his tools. The VFD allows him to change the speed of the tool. The other day he was making a custom handrail out of cherry. He was doing each side in one pass on his shaper and found the ideal speed to prevent the wood from burning that worked witht he speed of his power feeder.

I don't think there's a one option fits all solution. My biggest problem is that I don't like to run the RFC (in his shop) when I'm in between doing things. If I know that there's going to be a long delay then I'll shut it off but if I stop for just a few minutes it's a number of extra steps. It's in a separate room and it's a homemade one so starting it isn't hard but requires the right touch. It's kind of like running a dust collector when you aren't making sawdust. Some people wouldn't think twice, others would think about the power being spent for nothing.

[Jon Snider]

Thx to all.

No luck with 3phase anywhere near us.

Alex, I’m thinking about putting the generator in the closet which also contains the dust collector and the compressor, to limit the noise, and running a remote panel to a central location (or locations) more convenient for tool use.

Not it sure if this is possible, just an idea after talking to American Rotary and Kay and it’s possible I wasn’t on the same page.

Jon