Rotary Phase question

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Wdnich

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I understand rotary phase power and the conversion process. All my research tells me that once installed, I can run multiple machines off it, if I purchase a large enough phase convertor.

1. Would I wire it through the shop just like wiring another box? Install a breaker panel, route the output from the convertor to it, then run individual wiring from breakers to machines.

That has always been my limitations in the shop is power limitation.

My garage feeds off a 100 amp from the house.

2. Would this limit the use of the phase convertor?

3. Any special considerations to take into account? i.e special wiring, use specific breaker panels, etc.

Thanks for any help. This Bridgeport purchase has really pushed things to the next level in the shop. I understand I can run VFD's for everything, but want to move up to a larger compressor also. The medium size 110/220 I have been running never keeps up with the usage, and it is time to go larger for my needs overall. My research on VFD has said that some compressors do not do well because of the cycling on them.

I have been told the electrical gurus on here and help me solve my dilemma and questions. I look forward to the help.
 
100 Amp service should be more than enough to run a phase converter as big as you would ever need. You could run multiple machines at the same time with no problem. I would definitely do the breaker box route after the converter to protect you and the converter from accidental damage. The really smart guys here will have to gie you the code requirements for the proper wire gauges, but you should not have any supply problems at 100 amps from the service line to your house. If you are tapping into your home breaker box I would also consider putting a main breaker as a sub box at your house to allow you to shut off all power to the shop from there and to protect your home from a short also.

Bob
 
Motors that start under load like air compressors or hoists require extra starting torque and extra starting current. If the compressor will start up by itself to maintain your air supply, be sure you size the main breaker, wiring, and convertor to start the compressor while running another machine.

I have a 7 1/2 hp convertor on a 50 amp breaker. My 5 hp compressor can start up while I am running a 4 hp wood shaper plus a 2 hp dust collector plus a 1/2 hp feed motor. If it starts while I am running a 3 hp engine lathe, the voltage drop causes the starter on the lathe motor to drop out.

I tried piggybacking a second 7 1/2 hp motor on the convertor for extra starting torque. Then the lathe/compressor combination started and ran fine, but the shaper/collector/feed motor/compressor combination tripped the 50 amp breaker.
 
I have 2 shops, one for metal working, one for wood working. I have been running both rotary and static converters for over 25 years without problems. I use rotary converters for multiple machines as you suggest (shaper with feeder and dust collection). The machines that I want to turn on and off all day long (table saw, band saws etc.) are on static converters. Sliding table saw is 9 HP and runs great off a static converter. Thickness planer is 7.5 HP, static as well. This way I don't need to listen to the rotary all day long.
100 amp line is what I have as well, into each building from the main 200 amp service in the house. Never been a problem.
I do not have separate breakers after the converters, it would be nice, but I don't think you need it.
I do have 3 phase twist lock outlets so that machines can be disconnected easily (code in Mass.)
Good Luck, Larry
 
After reading the posts here, and further research. Pardon the illiterate electrical questions. I understand 110/220 but 3 phase is alien to me in a wiring sense.

I could convert all my garage wiring over to a three phase panel, and still run my lights and such, but have one central panel wired three phase, but running everything? If this is the case, seems like the next logical step in my shop for future usage.
 
Wdnich said:
After reading the posts here, and further research. Pardon the illiterate electrical questions. I understand 110/220 but 3 phase is alien to me in a wiring sense.

I could convert all my garage wiring over to a three phase panel, and still run my lights and such, but have one central panel wired three phase, but running everything? If this is the case, seems like the next logical step in my shop for future usage.
Click to expand...


If you are planning to bring in a separate 3 phase service to your shop, then yes you can run everything off of the 3 phase panel. Be mindful of the wild leg, about 180 V to neutral and ground.

If you are going to run your equipment with the existing service and from a RPC then I would not. I would use the existing single phase panel to handle all of the 120/240 single phase, and then install a 3 phase sub-panel down stream of the RPC to run the 3 phase equipment.
 
To add a question to the op if I may. This seems like a important thing to know and have found no info. With the RPC running off of 1ph 220 ( 2 legs powered and (generating) its own third leg which we cant be getting for free. How do we figure the amp draw of the RPC plus the machine draw to get a total? If we spin up the RPC with a pony motor to reduce the starting load how do we figure how much the RPC is using. Is the RPC getting a noticeable amp draw from the lathe/machine? Did I say that right? I'm no electrical engineer
 
psychodelicdan said:
To add a question to the op if I may. This seems like a important thing to know and have found no info. With the RPC running off of 1ph 220 ( 2 legs powered and (generating) its own third leg which we cant be getting for free. How do we figure the amp draw of the RPC plus the machine draw to get a total? If we spin up the RPC with a pony motor to reduce the starting load how do we figure how much the RPC is using. Is the RPC getting a noticeable amp draw from the lathe/machine? Did I say that right? I'm no electrical engineer
Click to expand...


there are mechanical losses in generating the third leg, you never get something for nothing.
you can measure the circuit draw by testing both hot lines on the single phase input.
the total circuit draw can easily be measured there.
 
psychodelicdan said:
To add a question to the op if I may. This seems like a important thing to know and have found no info. With the RPC running off of 1ph 220 ( 2 legs powered and (generating) its own third leg which we cant be getting for free. How do we figure the amp draw of the RPC plus the machine draw to get a total? If we spin up the RPC with a pony motor to reduce the starting load how do we figure how much the RPC is using. Is the RPC getting a noticeable amp draw from the lathe/machine? Did I say that right? I'm no electrical engineer
Click to expand...

All of the power comes from the 220V supply. Total single phase power input to the converter will equal total three-phase power out plus about ten percent for losses in the converter. There will also be some reactive current on the two-phase side. I'm not sure how much. Not a lot.

To figure how much current the system will draw from the 220V supply total up the power used by the loads, multiply by 1.1 to allow for converter losses, and divide by 220.
 
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