Electrical And Other Maintenance Formulae
In the construction and maintenance business, having the right equipment to do the job is vital. Having the right knowledge is just as important. We have listed some of the most requested formulae below. If there are others you want to have posted, please contact us.
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TO FIND |
SINGLE-PHASE |
THREE-PHASE |
DIRECT CURRENT |
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Kilowatts |
I x
E x PF
1000 |
I x
E x 1.732 x PF
1000 |
I
x E
1000 |
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KVA |
I x
E
1000 |
I x
E x 1.732
1000 |
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Horsepower (Output) |
I x
E x %EFF x PF
746 |
I x
E x 1.732 x %EFF x PF
746 |
I x
E x %EFF
746 |
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Amperes when Horsepower
is known |
HP
x 746
E x %EFF
x PF |
HP
x 746
1.732
x E x %EFF x PF |
HP
x 746
E x %EFF |
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Amperes when Kilowatts
is known |
KW
x 1000
E x PF |
KW
x 1000
1.732
x E x PF |
KW
x 1000
E |
|
Amperes when KVA
is known |
KVA
x 1000
E |
KVA
x 1000
1.732
x E |
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E = Volts I = Amperes %EFF = Percent Efficiency PF = Power Factor |
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Other Useful Formulae |
BTUs x 777.5
= foot pounds
BTUs x 3.93 ÷
10,000 = horsepower hours
BTUs x 2.93 ÷
10,000 = Kilowatt hours
BTUs per minute
x 13.0 = foot pounds per second
BTUs per minute
x 1.76 ÷ 100 = Kilowatts
BTUs per hour
x 2.93 ÷ 10,000 = Kilowatts
BTUs per hour
x 2.98 ÷ 1,000,000 = Boiler horsepower
(Celsius x 9
÷ 5) + 32 = Fahrenheit
Circular mils
x 0.7854 = Square mils
(Fahrenheit -
32) x 5 ÷ 9 = Celsius
Foot pounds x
2.29 ÷ 1,000 = BTUs
Foot pounds x
5.05 ÷ 10,000,000 = Horsepower hours
Foot pounds x
3.77 ÷ 10,000,000 = Kilowatt hours
Foot pounds per
minute x 1.29 ÷ 1,000 = BTUs per minute
Foot pounds per
minute x 3.03 ÷ 100,000 = Horsepower
Foot pounds per
second x 1.82 ÷ 1,000 = Horsepower
Horsepower x
42.4 = BTUs per minute
Horsepower x
33,000 = Foot pounds per minute
Horsepower x
550 = Foot pounds per second
Horsepower x
0.746 = Kilowatts
Horsepower boiler
x 33520 = BTUs per hour
Horsepower boiler
x 9.80 = Kilowatts
Horsepower hours
x 2550 = BTUs
Horsepower hours
x 1,980,000 = Foot pounds
Kilowatts x 56.9
= BTUs per minute
Kilowatts x 3412
= BTUs per hour
Kilowatts x 1.341
= Horsepower
Kilowatt hours
x 3412 = BTUs
Kilowatt hours
x 1.34 = Horsepower hours
Square inch x
273,000 = Circular mils
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Version 1.0.1
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