Electric Motor Power (Quick Facts)

Electric Motor Power (Quick Facts)
KW to HP converter

When I was fresh graduated from electrical engineering faculty, I joined the company, that I’m still working for.

I decided to help electricians who are working with me. They always needed help when it comes to electrical calculations.

I designed an easy free android app for kw to hp conversion and other important electrical calculations. You can find my android calculations Free app here. This is because KW to HP conversion is almost a daily calculation for every electrician.

Then, I designed a simple to use, hp to kw and, kw to hp converter online, to help you. You can find the converters below.

kw to hp conversion formula

How many kilowatts are in 1 horsepower? The kw to hp formula is very simple as 1 hp = (746Watt) 0.746 kw.

So, converting kilowatt to horsepower formula is, HP = KW * 0.746

How to Use kw to hp Formula?

  • To convert from kw to hp, divide KW value by 0.746
  • To convert from hp to kw you should multiply hp value by 0.746

Examples of hp to kw conversion

Example 1

How many KW is a 1 hp motor? This is so easy,

1 hp = 1* 0.746 = 0.746 KW.

Example 2

How many KW is a 20 hp motor?

As mentioned above, to convert from hp to kw, you should multiply hp value by 0.746.

So, a 20 hp motor  =  20 * 0.746  = 14.9 KW

Example 3

How many kW is a 100 hp motor?

A 100 hp motor  =  100 * 0.746  =74.6 KW

Example of kw to hp conversion

Example 1

An electrical motor with 15 kw what is its power in horsepower ? from the formula above,

15 kw= 15 / 0.746 = 20.1 hp.

Example 2

An electrical load with power of 100 KW how many hp is it?

As mentioned above, you should divide hp value by 0.746

100 KW = 100 / 0.746 =134.05 hp

Metric and Imperial Horsepower

Horse power has more than one standard. Two common of them are:

  • Mechanical or imperial horsepower. 1 HP = 745.7 Watt
  • Metric horsepower, which is approximately 735.5 watts

Electric motor Power consumption

Motor power consumption =  Motor power * Running hours.

Example 1

A 1 HP motor, means a 746 Watt power.

This motor will consume power in one hour equals 746 Watt Hour.

Example 2

How much power will A 5 HP motor consume in 20 minutes? 

Motor Power Consumption = Motor Power(in KW) * Operating Time

Converting 5 HP to KW = 5 *0.746 KW = 3.73KW

Motor consumption in 20 minutes = 3.73 * (20/60) – to convert minutes into hours =1.243KWH

Example 3

How much Power does a 25 hp motor use?

Motor Power Consumption = Motor Power * Time

Converting 25 HP to KW = 25 *0.746 KW = 18.65 KW

A 25 hp motor consumption in 1 hour = 18.65*1 =18.65 KWH

How to increase power of electric motor?

Increasing the motor power means, improving the motor efficiency. You can’t increase the electric motor maximum power by applying a higher voltage or connecting a gear box to its shaft. 

Electric motors are fixed power equipment. However motors don’t provide all the rated power they are designed to provide because of, mechanical and electrical losses.

We can improve the total efficiency of the motor, reduce losses and maximize the motor output power but, still its power not exceeding its nameplate power.

Tips to improve your motor efficiency:

Why do we convert motor power to to kilowatt?

As electrical engineers, we are looking at loads from electrical side. Watt is the unit of electrical power at all electrical equations. That’s why we convert motor power from horse power to kilo watt.

At work, if you are designing an electrical system for a load or a group of loads you will need to calculate exactly the load power in watt or kilowatt (kw) not in horsepower (hp).

But if the load is a single phase or a three phase induction motor, The power of the motor on the name plate is given in hp not in kw.

So, converting hp to kw is necessary to complete the electrical design for load control panel elements, cables and other protection devices.

Why does motor power in hp on nameplate?

Electric motors drive mechanical loads, which are in horse power not kilo watt, that’s why motor power on the motor nameplate is represented in hp.

While, the motor it self is an electrical equipment which power is represented in Kilo Watt in electrical calculations.

This explains the reason of HP to KW conversion when calculating motor current or power consumption.

Motor nameplate has the power of the motor in KW or HP. In most cases HP is the unit of motor nameplate power.

Reading the nameplate of the motor will till you the motor HP rating in the form of 25 hp, 10 hp etc.

I have written a detailed article about motor nameplate understanding. I highly recommend reading it. You can find it here.

Hereunder a 30 HP motor nameplate.
 
motor power in HP on the nameplate
motor power in HP on the nameplate

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HP to KW Conversion, Step By Step F...
HP to KW Conversion, Step By Step For Beginners