June 28, 2017

E = Voltage /  I = Amps/ PF = Power Factor /  EFF = Efficiency /  HP = Horsepower
To Find Direct Current Alternating Current
Single Phase Two-Phase* Four-Wire Three Phase
Amperes when Horsepower is known HP x 746
——
E x EFF
HP x 746
——-
E x EFF x PF x 2
HP x 746
——
2 x E x EFF x PF
HP x 746
——
E x EFF x PF x 1.73
Amperes when Kilowatts are known KW x 1000
——
E
KW x 1000
——
E x PF
KW x 1000
——
2 x E x PF
KW x 1000
——
E x PF x 1.73
Amperes when “KVA” is known KVA x 1000
——
E
KVA x 1000
——
2 x E
KVA x 1000
——
E x 1.73
Kilowatts E x I
——
1000
E x I x PF
——
1000
I x E x 2 x PF
——
1000
E x I x 1.73 x PF
——
1000
Kilovolt-Amperes “KVA”- I x E
——
1000
I x E x 2
——
1000
E x I x 1.73
——
1000
-Horsepower (Output) E x I x EFF
——
746
E x I x EFF x PF
——
746
I x E x 2 x EFF x PF
——
746
E x I x EFF x PF x 1.73
——
746

 

Note: Direct current formulas do not use (PF, 2, or 1.73)
Single phase formulas do not use (2 or 1.73)
Two phase-four wire formulas do not use (1.73)
Three phase formulas do not use (2)
* For three-wire, two phase circuits the current in the common conductor is 1.41 times that in either of the other two conductors.