How to Calculate Motor Power

what is the out Output speed required?

hope this is reduction gear!

lets say requirement of output speed is 50 RPM.

SO THE REQUIRED INPUT SPEED IS 16*50=800 RPM.

AND REQUIREMENT OF INPUT TORQUE IS (4t/16)/0.9(gear box efficiency considered)

= 0.277777t

SO YOU NEED A MOTOR THAT CAN GIVE YOU TORQUE OF 0.277777t at 800RPM.

If I'm not mistaken, your calculation doesn't show that you need the Output speed.

I am not clear what your question is?

Out put speed is normally final product requirements. and as it was not indicated but poster. so I have considered it for the purpose of example. do you think is it wrong?

HOW TO CALCULATE MOTOR POWER IN FEM /IEC

hi i want to select an electrik motor the datas are

800 kg load with shaft

15:1 gear ratio

100 rpm output shaft speed

motor power = ? kw

Torque=(5252.1*HP)/(RPM) or

HP=(T*RPM)/5252.1

How fast to you need it to spin. Are you concerned with starting torque. Do you need class A or B. There are some question you need to ask yourself.

Hope this helps

What is "4t"?

Automotive engines are rated using brake hp. You need to know the sustainable torgue and rpm which was at one time known as standard hp and is now known as continuous hp, which the way they rate engines for boats. The cooling system needs to match a different spec too.

Hydrax

Is this an Auto engine? No need to be vague when asking a question. Give us the goods.

It's been the convention in the USA, for most, to refer to electrically driven as motors and internal combustion as engines. If a person just said "motor", I would think electric motor. Say "engine" and I would think internal combustion.

I don't know if this is typical elsewhere.

A former german VW factory engine builder once said to me that any device capable of producing in excess of 1000hp was an engine, anything dot produced less was chust a motor.

True too in UK, probably moreso. On The Continent they're commonly both motors I think.

Disappointingly for an engineering website, I perceive a general confusing of 'power' or rate of work with the force/torque/tractive effort/call-it-whatever that underlies that power.

The gear ratio is irrelevant when it comes to power. Power is speed x torque. The gearbox is a constant power device, power out = power in. It merely steps the speed up and torque down (or vice-versa).

What you need to know is the speed and torque required at the load.

Fine gear ratio is insignificant if we forget about gear efficiency.

but

To to define the motor details. you need gear ratio.because you have to define the operating point of the torque speed curve,and one can not get it with out knowing motor RPM, AND motor RPM can not be defind with out knowing gear ratio and output speed.

You can have same out for two different motors, for example 500 RPM 1 KG-CM torque. and 1000 RPM 0.5KG-CM TORQUE.

You're correct Rakesh - While the gear ratio is not a factor in calculating the power, when it comes to actually selecting the correct motor you need to know the torque-speed characteristics required given the load and gear ratio.

POWER = IV * PF= .... WATS

I = CURRENT IN AMPER

V= VOLTAGE IN VOLT

PF (FOR AC MOTOR )= POWER FACTOR (PERCENTAGE FIG , TAKE 0.8)

REFER TO MOTOR SPECS, OR MOTOR NAME PLATE , OR AVAILABLE DATA SHEET

KAMAL AL-RAIS

if I did't know motor data but i know only pump data

I agreed with this formula.

However, if I were to calculate the real power downdown from the network by a motor? Is this formula still applicable?

As during the motor starting, current is high, cos phi is small. The real power calculated will be very small?

What about the reactive power? it will be very high?

wen u found out your answer ,pls let me know,coz your question is

ambigiuos(mechanically).

hi,

first of all i would like to know that,whether u will use ur motor for what purpose,

1.what type of load its going to drive.

2.how much of current is req. to drive ur load

3.ur motor is single or three ph.

thank uou,

naveen.m

get lost

hi

i have problem with motor that has no name plate and no data sheet i wish to know its rpm by knowing its number of pole how it happen