|
Typical Operating Costs of Farmstead
Equipment
Grain Aeration & Farm Motors
To calculate electricity used by single phase motors operating aeration
fans or other equipment, estimate the hours of operation (with careful
consideration of weather conditions and other variables), and apply the
following formula:
Motor input watts x hrs. of use/mo. ÷ 1,000
= _______kWh/mo.
Because of design differences and internal electrical
losses, motors have different power factors. This means
that more input watts are required than are indicated
by the motor’s rated horsepower. The formula above,
and the input watts in Table A, account for these varying
efficiencies. All values assume motors run at 80 to
100 percent of full load, and at rated voltage.
|
Single Phase
Motor Data for Estimating kWh Use
|
|
Rated Motor Size
in HP
|
Rated Motor Size
in Watts
|
Assumed Efficiency Percent
|
Input Watts
|
|
|
1/4
|
187
|
55
|
340
|
|
1/3
|
248
|
60
|
413
|
|
1/2
|
383
|
63
|
608
|
|
3/4
|
560
|
65
|
862
|
|
1
|
750
|
70
|
1,072
|
|
1.5
|
1,120
|
75
|
1,493
|
|
2
|
1,490
|
80
|
1,863
|
|
3
|
2,240
|
85
|
2,635
|
|
5
|
3,370
|
85
|
4,388
|
|
7.5
|
5,600
|
87
|
6,437
|
|
10
|
7,460
|
88
|
8,477
|
|
15
|
11,000
|
90
|
12,222
|
|
Example:
Determine the amount of electricity used during
the month of May by a 1/2 hp ventilation fan when
it runs an average of 12 hours per day.
(Motor Input watts x 12 hrs/day x 31 days) ÷
1,000
(608 x 12 x 31) ÷ 1,000 = 226kWh
Multiply kilowatts times 6 cents to get cost.
|
The above information has been provided from the National
Food and Energy Council.
Livestock Waterers
|
Application/Operation
|
kWh/Head/Season
|
Comments
|
Hog waterer, dual trouch
— open lot
— sheltered
|
5-10
2-3
|
1" insulation
|
Cattle waterer
— open lot
— sheltered
— inside barn, semi-enclosed
— outside, very well insulated
|
6
5
4
2-3
|
1" insulation
2" insulation, floating covers
|
Combination hog & cattle waterer
— open lot
— sheltered
|
10
8
|
1" insulation
|
| Data mainly from Iowa and Missouri,
during typical winter months. For more northern
states add 15 percent for each tier of states to
the north. |
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