108 volts at the top of the well while running the 1/2hp pump.

softdown
softdown Solar Expert Posts: 3,901 ✭✭✭✭
in Off Grid Solar & Battery Systems #1
Thinking I had 118 volts before connecting the pump. The 1/2hp pump consumes 1100-1300 watts while running. 

108 volts is a low measurement and the pump is another 100' down the well. However....I believe that I have read that well pumps are designed to run on lower voltages....such as this.  

Is there a problem?

I think that I can push up the voltage of my Outback inverter. Sometimes I consider doing that since many of the shops wire runs are quite lengthy. 
First Bank:16 180 watt Grape Solar with  FM80 controller and 3648 Inverter....Fullriver 8D AGM solar batteries. Second Bank/MacGyver Special: 10 165(?) watt BP Solar with Renogy MPPT 40A controller/ and Xantrex C-35 PWM controller/ and Morningstar PWM controller...Cotek 24V PSW inverter....forklift and diesel locomotive batteries
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  • Estragon
    Estragon Registered Users Posts: 4,496 ✭✭✭✭✭
    #2
    I think grid voltage regulation is ~ +/-10%, so 108v is at the low end of that. Low voltage means more current in the pump, which while it may be okay, can't be a Good Thing.

    Assuming doing so wouldn't overvoltage anything nearby, putting the voltage up a tick or two on the inverter might not be a bad idea IMHO.
    Off-grid.  
    Main daytime system ~4kw panels into 2xMNClassic150 370ah 48v bank 2xOutback 3548 inverter 120v + 240v autotransformer
    Night system ~1kw panels into 1xMNClassic150 700ah 12v bank morningstar 300w inverter
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  • jonr
    jonr Solar Expert Posts: 1,386 ✭✭✭✭
    #3
    Franklin allows  a 5% wire voltage drop running at maximum nameplate amps.   Plus, I assume,  5% voltage tolerance in the unloaded supply (or maybe 10%).  So 120 * .95 *.95 = 108V is OK.  But with the 100 extra feet and probably not at nameplate amps, you may be slightly out of spec.

    You could throttle the pump a little to reduce amps.  

    I am available for custom hardware/firmware development

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