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How to figure...

Volts, Amp & Watts Formulas

Volts X Amps = Watts

Watts / Volts = Amps

Watts / Amps = Volts



Irrigation Formula for Hours of Run Time


              Total KwH for season                   =   Total Hours of Run Time 
(746 Watts X Total Horsepower)/1000



Conversion Formula for Amps to KwH's


Voltage used by motor or appliance X Amps X Hours of Use   =  Total KwH's Used  



How much it cost to run an appliance


Appliance's Watts  X rate   =   Cost to operate/hour

Wattage information may be obtained by looking at the appliance nameplate, usually labeled on the back of all units. Bluestem’s electric rates vary from winter to summer.  Click here to see our single phase rate.  In the examples below, an average rate of 10 cents per kilowatt hour is used. 

Example One: 
150-watt floodlight used for security lighting with a duty cycle of 8 hours and at a rate of 10 cents per kilowatt hour.

150 X .10 = $0.015/hour

Example Two: 
One thermostatically controlled 1,000 watt stock tank heater plugged in for 12 hours. The duty cycle is estimated to be 5 hours based on outdoor temperatures. Remember, only calculate the time in which the appliance was heating. 

1,000 X .10 = $0.10/hr X 5 hours actually running = $0.50 for a 12 hour period

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