Author Topic: 3 phase to single phase  (Read 5400 times)

DRDEATH

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3 phase to single phase
« on: January 24, 2010, 08:27:00 PM »
So I see an add on ebay someone selling plans on changing 3 phase to single phase 220 volt. He explains how it is so simple a 4th grader can do it and it work as good as 3 phase. True or false. Thanks, Mike
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Doug

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Re: 3 phase to single phase
« Reply #1 on: January 24, 2010, 09:31:45 PM »
Its so simple you can make money on Ebay from it

Easiet way is with a MG set.

Newest way is a rectifer DC link and inverter

Most interesting way using the scott T transforner connection to go 3 to 2 phase then 2 to single with a rotoray induction converter.

There are still other ways I haven't given much though to.

That help?
Clear as mud?
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DRDEATH

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Re: 3 phase to single phase
« Reply #2 on: January 24, 2010, 11:08:59 PM »
MUD is not the word that come to mind. The only reason I was intrested is that unless you are a commercial business no one has 3 phase. I have seen bargains for 3 phase equipment. If the change is made do the machines or motors run properly? If you go on ebay you should be able to find something from a man who is selling the plans for about 10 dollars, which is really not that expensive. I am just curious if he is selling a bill of goods or something that will really work. Thanks, Mike
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buickanddeere

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Re: 3 phase to single phase
« Reply #3 on: January 24, 2010, 11:12:52 PM »
  If you can get at both ends of the windings. A 3 phase 120/208 alternator can be wired for true 180 degree single phase 120/240 power. Capacity  will be 57.7% of nameplate rating.
  Two sets of windings have to put in series bucking each other.

Doug

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Re: 3 phase to single phase
« Reply #4 on: January 24, 2010, 11:52:53 PM »
You want to run 3 phase equipment on single phase?

If thats the question yes its easy to do.

I have 600v 3 phase power in my shop because I have some surplus industrial equipe ( grinder drill press ). I'm too cheap to buy anything so I made it work lol

Do a web search all the info is out there.

Not to argue with Buckbut you can manage to get 75% or more rated power on some machines if you make a good rotory converter
« Last Edit: January 24, 2010, 11:55:21 PM by Doug »
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DRDEATH

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Re: 3 phase to single phase
« Reply #5 on: January 25, 2010, 08:04:37 PM »
Thanks Doug. I will pursue the because I to am also cheap. i think SMART is a wiser choice of words. I also tried to add a signature to my post. Wont know if it works until I send a post. If it works I may try a picture next. Mike
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Doug

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Re: 3 phase to single phase
« Reply #6 on: January 25, 2010, 10:02:35 PM »
look for a book called electrcial machines drives and power systems printed in the 70s. the author made a realy good single to 3 pahse converter and explaination of opperation .

http://www.amazon.com/Electrical-Machines-Drives-Power-Systems/dp/0131776916?tag=dogpile-20

Find the early addition grey book printed in the late 70s. The electronics are of no use or interest
« Last Edit: January 25, 2010, 10:05:37 PM by Doug »
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fabricator

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Re: 3 phase to single phase
« Reply #7 on: January 26, 2010, 11:34:56 PM »
Find a local industrial surplus outfit and see if they have any  ECMs, electronic motor control I believe, surplus units are usually pretty reasonable, you can go from single to three phase and control rpms and several other parameters.
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DRDEATH

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Re: 3 phase to single phase
« Reply #8 on: March 07, 2010, 03:00:01 PM »
Well I made a rotary converter. I found a good 30 hp 3 phase at junk yard. I use a 1/4 hp single phase as a pony motor to start big motor turning up to speed. So far everything looks good. I have less than 200 in whole system. I think that's pretty good considering I didn't know anything before I started. Mike
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Doug

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Re: 3 phase to single phase
« Reply #9 on: March 07, 2010, 04:12:38 PM »
30????

Thats like 10 times larger than needed you know......

Did you add any run capacitors?
they help....

Pony motor is not realy needed if you add some caps. HOWEVER your motor is so much larger than normal it might cause trouble of you tried to motorize it and do an across the line start

PIctures please...
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