[TheForge] 3 Phase Converter DIY

Sun Dec 8 16:40:00 2002

I think starting depends on if you have the right amount of capacitance 
in your converter. It also depends on whether your converter is working 
right; last year I thought I had a 3HP motor that was much harder to 
start than other motors I'd tried in the past, but it turned out a wire 
had come loose in my converter!

As an example, I've started a 20HP motor (no load) off of a net 10.5HP 
idler converter.

Darrell wrote:
> If your idler motor is not at least as large as the load you are trying to
> start, you will stall the idler.
> On the other hand, if you have a 5 HP idler and you start a 5 HP motor with
> it you can now start another motor that is 10 HP. Then if you have enough
> amperage available from your 220 circuit, you could start another motor that
> is 20 HP. Each running motor adds capacity to the system.
> This is from personal experience. I have a 5 HP phase converter. I can not
> start a 7.5 HP motor even with no load unless I have other motors running.
> On the other hand transformers in the 3 phase circuit do not add anything to
> the capacity and may not need as big of idler motor to work.
> 
> Darrell
> 
> ----- Original Message -----
> From: "T.L.Tallman" <[email protected]>
> To: <[email protected]>
> Sent: Sunday, December 08, 2002 5:42 AM
> Subject: Re: [TheForge] 3 Phase Converter DIY
> 
> 
> 
>>i have friend who has a 30 hp 3 phase motor for sale
>>terry
>>----- Original Message -----
>>From: "Ed F" <[email protected]>
>>To: <[email protected]>
>>Sent: Sunday, December 08, 2002 7:20 AM
>>Subject: Re: [TheForge] 3 Phase Converter DIY
>>
>>
>>
>>>Hi Steve,
>>>
>>>Thanks.  I have a few.
>>>
>>>1). Everyone says that the generator motor has to be rated for the HP
>>
> you
> 
>>>will drive plus some, except a friend who is sending me something out of
>>
> a
> 
>>>text book on it.  He says that only one set of windings are doing much
>>
>>work
>>
>>>so you can use a motor about 1/3 the rating of your consumption.
>>>
>>>By that, a 1 HP generator would have the current running through one set
>>
>>of
>>
>>>windings that your 3 HP driven motor uses.  He argued that the windings
>>
>>are
>>
>>>rated for heat not current, and the one working leg is wound together
>>
> with
> 
>>>the 2 low current legs so it's fine.
>>>
>>>It's not really a big deal for my press motor which takes about 5hp, but
>>
>>if
>>
>>>I make one for my welder at 1 to 1 I would need a 30 HP motor!  Quite a
>>>difference from 10.
>>>
>>>2). Did you do anything for fusing?
>>>
>>>3). What precautions did you take with your capacitors to keep from
>>
>>getting
>>
>>>zapped?
>>>
>>>4). Did you have to play much with your capacitors to get the motor
>>>balanced?  Did you balance the current or voltage?
>>>
>>>5). Did you start the generator with a capacitor?  I have heard of some
>>>people using a small single phase motor or even a pull start.
>>>
>>>Thanks again,
>>>
>>>Ed
>>>
>>>
>>>----- Original Message -----
>>>From: "Steve Smith" <[email protected]>
>>>To: <[email protected]>
>>>Sent: Friday, December 06, 2002 7:52 PM
>>>Subject: Re: [TheForge] 3 Phase Converter DIY
>>>
>>>
>>>
>>>>I've built several converters, I'll be happy to help if you have
>>>>questions (as will several others, I'm sure).
>>>>
>>>>Steve Smith
>>>>
>>>>Ed F wrote:
>>>>
>>>>>I want to look into making a 3 Phase converter to run a 3 phase
>>>>
>>forging
>>
>>>>>press motor off of 220 single phase.  I can get away with a 5 hp but
>>>>
> I
> 
>>>will
>>>
>>>>>probably go to a 7.5 hp.  I ordered the plans from ABANA way back
>>>>
> and
> 
>>>lost
>>>
>>>>>them.  I remember them  being about 3 pages and on the minimal side.
>>>>
>>>I'm
>>>
>>>>>thinking that by now someone probably has better directions on the
>>>>
> web
> 
>>>>>somewhere, or maybe someone here is willing to share experience?
>>>>>
>>>>>Ed
>>>>>
>>>>>_______________________________________________
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>>>>>
>>>>>
>>>>
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>>>>
>>>
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>>
>>_______________________________________________
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>>
> 
> 
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