Load Max Equipment Sales | Equipment Dealer for Gas and Diesel Commercial Generators, Light Towers and Trailers

Power Calculations & Formulas

Below is a quick reference guide of some power calculations and formulas.  If you have any questions about computing your power needs, do not hesitate to give us a call or send us an email.

 

Power Factor (P.F.) Formula

Single Phase

Three Phase

kW / kVA

kW / kVA

kW Formula

Single Phase

Three Phase

(Volts x Amps x P.F.) / 1000

Or

kVA x P.F.

(1.73 x Volts x Amps x P.F.) / 1000

or

kVA x P.F.


kVA Formula

Single Phase

Three Phase

(Volts x Amps) / 1000

Or

kW / P.F.

(1.73 x Volts x Amps) / 1000

or

kW / P.F.

 

Amperes – When kW is Known Formula

Single Phase

Three Phase

(kW x 1000) / (Volts x P.F.)

(kW x 1000) / (1.73 x Volts x P.F.)

Amperes – When kVA is Known Formula

Single Phase

Three Phase

(kVA x 1000) / Volts

(kVA x 1000) / (1.73 x Volts)

Required Prime Mover Horse Power Formula        

kW / (Alternator Efficiency x 0.746)

Frequency (Hertz) Formula

(Number of Poles x R.P.M.) / 120

Revolutions Per Minute (R.P.M.)

(Hertz x 120) / Number of Poles

                             

Voltage Regulation (in%) Formula                           

(No Load Voltage – Full Load Voltage x 100) / Full Load Voltage

Speed Regulations (in%) Formula

(No Load R.P.M. – Full Load R.P.M. x 100) / Full Load R.P.M.

Voltage Dip Factor (Motor Starting) Formula

(100% - Voltage Dip%) / 100