How do you calculate the starting current of a motor?

An induction motor, starting “across the line”, will typically have an instantaneous draw 6x the kw it is rated to run at. e.g. a 10 hp motor is rated at 7.46 kw, so on starting it may draw 75 kw. On 480 volts 3 phase, the amperage will be I = W / (E x 1.73) = 75,000 / (480 x 1.73) = 90.4 amps.

How do you find the nominal current of a motor?

The motor FLA calculator uses the following formulas:

  1. Single Phase AC Motor FLA (Amperes) = (P [kW] × 1000) / (V × cos ϕ)
  2. Single Phase AC Motor FLA (Amperes) = (P [HP] × 746) / (V × cos ϕ × η)
  3. Three Phase AC Motor FLA (Amperes) = (P [kW] × 1000) / (V × 1.732 × cos ϕ)

What is the starting current of 1 hp motor?

For a 1 HP 3phase induction motor draws a current =W /V, so 1 HP is equal to 746 watts, or rounded off to 750 watts, so it will be 750 /415 volts =1.7 amperes, approximately and at a powerfactor at unity means 1.

How many amps is 3 horsepower?

AC Motor Full Load Amperes

HP 200 Volts 440-480 Volts
1 4.8 2.1
1.5 6.9 3.0
2 7.8 3.4
3 11 4.8

How do you calculate the maximum current of a motor?

I= P/(1.732*V*Cos pi)



Here three-phase full load current is equal to the power divided by 1.732 times of line to line voltage and power factor.

IT IS INTERESTING:  What are the different types of transmission fluid?

How many kW is a 5hp motor?

Hp to kW Conversion Table

Horsepower Kilowatts Rounded Kilowatts
1 hp 0.745699872 kW 1 kW
5 hp 3.72849936 kW 4 kW
10 hp 7.45699872 kW 7 kW
15 hp 11.18549808 kW 11 kW

How much current is needed for a 5hp motor?

Common Horsepower to Amps Conversions

Horsepower Amps Voltage
4 HP 27.6 A 120 V
4.5 HP 31.1 A 120 V
5 HP 34.5 A 120 V
10 HP 69.1 A 120 V

How much current does a 1 hp motor consume?

When the 1 HP motor is running continuously for 24 hours, 17.904 units of Power will be consumed.

Car repair school