From: mung_me@att.net   
      
   On 3/20/2013 11:57 PM, philkryder at gmail wrote:   
      
   Overcompensating will lead to current leading voltage, and when your   
   motor loads that is what will happen. I don't see this as bringing any   
   happiness to the assorted solenoids et all.   
      
   You have a small motor, power factor correction at idle has no real   
   benefit as the savings are minor. If you really want a better PF for   
   some altruistic reason, then you will need to switch out the   
   compensation when demand goes up.   
      
   My recommendation is to just remove the capacitors.   
      
      
   > A couple years back some folks in this group helped me to use a KillaWatt    
   device to deterimine powerfactor on some "lighly loaded" ac motors.   
   >   
   >   
   > Time has passed.   
   >   
   > I installed corrective capacitance based on my spreadsheed and formulas   
   provided by others in the group. Thanks for all the help.   
   >   
   > More Time passed.   
   >   
   > What we learned recently is that though the AVERAGE powerfactor is "low" -   
   .5 or less sometimes,   
   > there are SPECIAL PEAK LOAD EVENTS that may last for a few seconds (less   
   than 5) every minute or two.   
   >   
   >   
   > Coincident with those peak load events, control circuits in the same   
   "neighborhood" - i.e. cicuit need to fire control solenoids for hydraulic   
   controls. The motor is a half-horse 120v 60 cycle that drives a hydraulic   
   pump. On average - 95% of the time -   
    there is no load - but, when there is a a solenoid opens a valve to a   
   hydralic motor and then, other solenoids open valves to hydraulic cylinders...   
   >   
   > You can guess where this is going.   
   >   
   >   
   > When the load is applied voltage drops from 120 nominal to 106 or so.   
   Solenoids fail to fire. Power factor changes dramatically.   
   >   
   > So, given that my KillaWatt only does averages, we rented a Fluke meter that   
   records mins and maxes within each one-minute interval.   
   >   
   > I'm inclined to re-tune the capacitors based on highest power Factor  seen   
   over an entire 10 hour shift, rather than the average seen by the Killawatt   
   while I happen to be looking.   
   >   
   > Any other suggested actions?   
   >   
   > Also, "what happens" with a corrected circuit at a 98% power factor when the   
   load increases and the motor's power factor rises from .5 to .85 causing the   
   circuit to be "over corrected"   
   >   
   > thanks in advance.   
   > Phil   
   >   
   >   
   >   
   >   
   >   
   >   
   >   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)