No, AC motors don’t work that way.   Though you have the right idea, it’s just 
called a variable frequency drive.    Rectify the AC into DC, stick it in a big 
capacitor, and turn it back into AC at whatever frequency you want the motor to 
spin at.   Slowly ramp up the speed and it takes a lot less energy, at least in 
a pumping application.   Or really any application where starting the load 
moving doesn’t require a lot of breakaway torque.    

Mark

> On Jun 3, 2021, at 10:28 PM, Steve Jones <[email protected]> wrote:
> 
> I assume you cant just put a massive capacitor on it?
> 
> On Thu, Jun 3, 2021 at 7:14 PM Jaime Solorza <[email protected] 
> <mailto:[email protected]>> wrote:
> Exactly...that's what they messed with it.
> 
> On Thu, Jun 3, 2021, 5:56 PM Chuck McCown via AF <[email protected] 
> <mailto:[email protected]>> wrote:
> Systems I worked on like this had an alternator circuit that would make two 
> main pumps take turns each operation. 
>  
> I also worked on remote C.O. buildings that had dual HVAC systems.  After a 
> power failure the generator would come on but it could not start both systems 
> at the same time.  I had to put a cut out on one of the HVAC systems to kill 
> it if there was a commercial power outage.
>  
> Unless you work with large motors, you have no appreciation for starting 
> loads. 
>  
> From: Jaime Solorza <>
> Sent: Thursday, June 3, 2021 5:02 PM
> To: AnimalFarm Microwave Users Group <>
> Subject: [AFMUG] Fort Bliss lift station troubleshooting
>  
> After going through the drawings and consulting with original design engineer 
> on this project installed in 2007, we found one issue right away...the water 
> company techs made some changes to try to get pump 3 and 4 to run 
> simultaneously...kept tripping breaker. 
> The system was designed for 600amps maximum but when pump 3 starts up it goes 
> above 600, drops and stays at around 204.x while working, then when they turn 
> pump 4, it starts up above 600amps and trips breaker.
> The system was designed to work with pump 1, a smaller motor and pump 3 , and 
> pump 2, same as 1, works with pump 4.
> On Monday, we will rewire to original design and make some changes to PLC 
> programming and relays....they need some better level transmitter installed 
> but that's another project.
> BTW, the enclosure is water tight and under a canopy for added protection.
>  
> 
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