# A few pics of the phase converters Ive slapped together



## 8ntsane (Aug 26, 2012)

Here is a few pics of phase converters Ive built for friends. They are all pony start, as I dont care for all the caps involved , and like things simple.
The first pic is a 10 hp 1200 rpm
The second pic is a 7.5 hp 3650 rpm
The last pic is a 15 hp 1750 rpm
The pony motors are all 1/2 hp or less, and 120 volt


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## Rbeckett (Aug 26, 2012)

Paul,
Do the three phase motors run 1:1 with the pony motor, or do you adjust their speed with pulley diameters to change the hertz output or power?  I am a total newb to PC's so I am probably asking dumb noob questions, but if ya dont know ya dont know.  Thanks for the great pics.
Bob


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## 7HC (Aug 26, 2012)

I want to ask a dumb question of my own as I too know nothing about PHCs.

I can see that the little motor is driving the big one.  Does the output from the big one (I'm guessing that it's working in reverse as a generator),
actually provide three phase current to power a three phase motor, or does it add a couple of phases to an existing 120v single phase supply?

Thanks,

M


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## Old Iron (Aug 26, 2012)

Paul is there away to kick the belt after the 3 phase gets up up full speed?

Paul


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## 8ntsane (Aug 26, 2012)

Bob
You must be noticing the pulley sizing. The pulley sizes are to get the 3- phase motor up to the name plate speed. I allways like to get them spun up to that speed so they start very easy, and low in rush power.
You can spin the 3-ph motor up to lower speeds, and they will still fire up. What Ive found, if you bring the speed up to name plate rpm before throwing the power at it, you dont have the inrush current that dims the lights or effects other house hold items. This also stops from tripping the breaker too.

The pony motor, and the 3-ph load motor dont allways match each other RPM wise, so you just use the pulleys to get the load motor up to name plate speed. I have built a few that spun up higher than the N.P speed, and started up just fine too. The closer you come to N.P, the less in rush.


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## 8ntsane (Aug 26, 2012)

7HC said:


> I want to ask a dumb question of my own as I too know nothing about PHCs.
> 
> I can see that the little motor is driving the big one. Does the output from the big one (I'm guessing that it's working in reverse as a generator),
> actually provide three phase current to power a three phase motor, or does it add a couple of phases to an existing 120v single phase supply?
> ...



The small motor is only used to get the big guy spun up to speed, once you throw the power to the big motor, and it up and running the power to the little 120v motor is shut down.

The pony motors have a hinge at one side of the motor base. This allows you to just lift the pony motor upwards, and the belt will derail itself. I have tryed a few without removing the belt, but there is a few problem with that. The load motor doest at all care if it spins the little guy, but when using these low hp pony motors, Ive found they will wear the bearings out if left spinning. The other thing is, when using these low hp pony motors, they often require the belt to be loose, so they slip while turning over the bigger one. If left on and the belt slipping, the belts get over heated. The power to the pony motor is allways shut off after the load motor is running.

Yes , single phase power into the 3-ph motor, and kicks out 3-ph out put, once its running.


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## Metalmann (Aug 27, 2012)

Thanks, guys. There are a lot of electrical questions I may have later, now that I know who to ask.


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