Answer / senthil kumar.i

while name plate is missing,

first we are taken the details from the motor bellow
1. torque
2. Motor Rpm.

sutitute the given formula.

BHP = 2*3.14*T.N / 60 * 746

where T is torque and N is motor Rpm.
torque unit is nm.
we can get the Missed name plate motor HP.

Answer / manoj

1. Switch on the motor & measure the current (i) using Clamp
meter.
2. The calculated current (i) should be multiplied with
250Watts.
3. The result value should be divided by 230Volts i.e the
present voltage ratings.
4. The result of the step 3 will be the induced motor
ratings in HP.


This is illustrated with a small example below:
Assume that a motor of 5HP 3-phase is not having a name plate.

For 5HP motor, the current ratings will be around 7amps.
As we all know that, 1amps=250Watts.
So, multiply 7amps with 250Watts i.e 7x250=1750
The result answer 1750is divided by present input voltage
i.e 230V.
1750/230=7.6
Hence the result answer is the induction motor's rating in HP.



Another easy method to calculate this is:
check the current & divide it with 1.39(current rating of 1
HP motor)
the result answer will be the motor rating in HP

Answer / seshasai bagadi

APPLY 440 VOLTS AT NO LOAD TO THAT MOTOR AND FIND THAT NO
LOAD CURRENT BY CLAMP METER.,
AS INDUCTION MOTOR TAKES 30 % OF FULL LOAD CURRENT AT
NOLOAD .,HENCE RATING CAN FIND BY USING..
P=(1.732)(V)(I)
WHERE V-RATED VOLTAGE(440V)
I-FULL LOAD CURRENT (CALCULATED)
P-RATING OF MOTOR IN KW
ASSUME UNITY POWER FACTOR

Answer / puja

HP = 2*3.14*t*n/60*746

Answer / sajid khan

check the current by clamp meter on no load condition.
multiply this no load current to 2.5-3, and hence you will find your final answer.

Answer / ramendra shukla

As we know the Relationship of Mech. HP with Elect. KW is-
HP = 0.734 KW
P= VI in KW (let PF is unity or pure resitive load)
First we will get the the Voltage V, and then the current,
C in amps By this we will calculate the Horse power ,HP.

Lets have an example
Q:- A motor is taking the current as 30 amps & the voltage
is having 420 calculate how much HP it have??
ANS :
We know HP =0.734 KW

& P= VI cos@ (let cos @=1 or pure resitive load)
then
P = 30x420x1 KW
= 126 KW
So,
HP =0.734x126 :=92 HP

what is the use of spst switch in performing experiment on self excited dc motor?

2 Answers  

A separately excited dc motor having 2 ohm armature resistsance draws a current of 10A and torque developed is 20 Nm under rated field condtion. the speed of the motor under the rated field condtion , when it is connected to a 100V DC source and delivering 10Nm torque....

2 Answers   DRDO,

in domestic service connection,what is service main?

1 Answers  

How to calculate or formula to calculate rhe power in 2 phase system ??

0 Answers  

WHATIS TIME CONSTANT? WHATIS ITS SIGNIFICANCE? ILLUSTRATE THROUGH EXAMLES.

0 Answers  

When do you use a VFD motor?

1 Answers  

how to calculate the no. of turns in secondary side of CT?

1 Answers  

IS it possible for a feedbacksurge to travel over a wireless connection?

1 Answers   HP,

Why should we use jelly filled armoured cables in underground Communication system? What is the use of the Jelly? If we go for unarmoured, then what happens?

1 Answers   Prasad Group,

In UPS, battery connections if parallel connection given, what will happen?

2 Answers  

Whether the LIGHTNING is AC or DC?

9 Answers   Bhel, IEEE,

what is the mazor difference between the induction transformer and synchonous motor?what is the similarity between them?

1 Answers