Generally for electric motor size,it rated by horsepower (hp) or kilowatts (kW) unit.We can recognize the electric motor size when refer to their kilowatts or horsepower.So from power (kW/hp), how we can know the full load ampere for electric motor?
This time i want share about how to calculated the full load ampere (FLA) of electric motor from their power rated.It not difficult if we know the right formula to get the answer.From this calculation we only can estimate the value of full load ampere.
We cannot get the actual full load ampere because it depend on efficiency of motor.If electric motors have a higher efficiency rating,it will draw fewer amps, for example a 10 HP motor with a 60% efficiency rating will draw about 65 amps at 230 VAC compared to about 45 amps for a motor with a 80% rating.
How to calculate from power ( kW & HP ) to ampere ( I )?
1) Kilo watt (kW) to ampere ( I )
For 3 phase power supply ; kW = I x V x 1.732 x pf
For 1 phase power supply ; kW = I x V x pf
Example : 1 unit compressor size rated 37 kw,415 VAC,3 phase and 80% pf,calculate the full load ampere?
Calculation :
kW = I x V x 1.732 x pf
I = kW / (V x 1.732 x pf )
I = 37 / (415 x 1.732 x 0.8 )
I = (37 / 575) x 1000
I = 64.4 ampere ( full load ampere)
2) Horse power ( hp ) to ampere ( I )
First we must convert from hp to kW using this formula :
1 Hp = 0.746 kW
After that use the formula kW to ampere :
For 3 phase power supply ; kW = I x V x 1.732 x pf
For 1 phase power supply ; kW = I x V x pf
Example :-
1 unit induction motor power rated 25 hp,200 VAC,3 phase,90 % power factor,calculated the full load ampere.
Calculation :-
kW = 25 hp x 0.746
kW = 18.65
kW = I x V x 1.732 x pf
I = kW / V x 1.732 x pf
I = 18.65 / ( 200 x 1.732 x 0.9 )
I = (18.65 / 311.76) x 1000
I = 59.8 ampere ( full load ampere )
Should we take into consideration the efficiency of the motor?.
For efficiency is not compulsory if we don’t have the value.,we can ignore the value :D
Can you tell me what amperage draw would be for a 1.1 hp motor running on 24 volts
If it’s single phase then
p=vi.pf.
1.1×746=24ix1
i=34.2amp
If its three phase then
p=1.732vixpf here pf=.8
i=24.67amp.
What is the current draw for a 3phase 415V 60HP electric motor?
three phase then
p=1.7328VIxpf here pf=.8
I=P*.746/(1.732*415*.8)*1000=77.84Amps
What is the 3 Phase AC Current draw for an 80A DC Motor running at 440VDC?
Thank you
Robert Karkafi
Engineered Drive Systems
Los Angeles, Ca
In your formula Efficiency factor is not accounted – is there some reason for this. I thought the formula was kW = I x V x 1.732 x pf x Efficiency?
Yes Steve..it true.You can include with efficiency value if you know but if not you can skip it.
Send current formula
What is 1..732
Square root 3 = 1.732
√3 = 1.732
Hi. May I help you to calculate the electrical load list of power plan.
amir.masror@gmail.com
Hi! Is the power factor required also? or If I didn’t know the p.f. can I use 0.8? Our motor specs are 18.5KW, 460V, 3PH.
Hi,Normally i just put PF to 1 but it’s ok to put PF 0.8
hiii
you can also use
KW = √3 × V× I × cos¢
cos¢ = 0.8
Yes Akash,Thanks for sharing the formula
a motors rating 10kw !!!!! what its means this motor will consume 10 kw per sec ??? or 10 kw per hr?????
it will be in hr
how did you come about the 1000?please assist
how can i found 3 ph motor efficiency
You should say P = √3VIcos¢
Watt is the unit of power, to convert Watt to kilo watt divide by 1000
Then no confusion about 1000
a 48v dc motor with nominal power 11kw. how can i calculate pf
WHAT IS THE FORMULA AS UNDER:
440 V, 60 H.P., 55 AMPS, PF .95 & 12 HOURS
NOW WE WANT HOW MUCH UNITS WILL CONSUMPTION AS ABOVE POINTS.
60 multiply by 0.746 as converting ratio you will get watts per hour and multiple for 12 hour is 44.760 kilowatts per hour multiple for 12 hour is 537.12 for 12 hour, calculate this kw multiple ain unit charges by electricity per unit you will get your bill……
1 HP = .746 KW
GIVEN DATA IS 20 HP AND WE NEED TO FIND THE AMPS RATING
20 HP = 20 * 0.746
= 14.92 KW
HERE 14.92 KW , IT IS 3-PHASE ( ABOVE 4 KW WE CONSIDER 3-PHASE AS PER NEC )
P = √3 V I cos¢
P = 14.92 KW
V = 415 V
cos¢ = 0.8
√3 = 1.732
I = ????
P = √3 V I cos¢
I = ( P / √3 V cos¢ )
I = (( 14.92*1000 ) / ( 1.732 * 415 * 0.8 ))
I = 25.94 A
I = 26 A
yes
KW/KVA
I made a blower. The fan is OD 33.5″
6″thickness and 55 kg Wight
Which power motor required (HP)
I made a blower. The fan is OD 33.5″
6″thickness and 55 kg Wight
Which power motor required (HP)
2800 rpm
hiee, for 3 phase 1kw ac motor how much the maximum current rating is acceptable?
How to calculate amper when horsepower is given for 3 phase ?
A 20 H.P, 3 Phase supply ,50Hz , 440 Volt in induction motor .find out full load current?
we are having 3-phase BLDC hub motor (800W ,48V).
we have to run this motor for 2 hours with Lithium-ion battery.
Then how to decide the battery capacity?
how to find pf
kw/kva
Is motor rpm is necessary to calcultae full load current?
Short trick kw to full load ampere
Not necessary. Full RPM = Full load ampere
how to Calculate the actual running current of a motor such as: moter name plate:
P=75KW
V=440
Pf=.89
phase=3
incoming V=480V using softstarter
which type (watt) inverter require for run 1 hp electric motor.
pls given best answer .
i phase 230 volt motor
Hi Gents
I have a pump with Diesel engine 1450 RPM, 160 KW, Soi wants to change the diesel engine by Electrical Motor 1450 RPM, 160 KW, 3 Ph, 380 Volts, 50 Hz, so I need to know how many Amp. I need for each one phase ( they write in the motor 280 Amp is this total for all 3 ph or 280 Amp for each one phase ) Cheers….
Hi, if I’m having 15 kW motor , 3phase, pf .8 star-delta starter. How can I find How much current will flow in star condition & how much in Delta?! Pls answer. Thank you
Starting current of 10 HP induction Motor is_________ times full load current
A)5
B)8
C)10
D)20
Answer-____?_____
It depend what motor starter that you use..
DOL –> 5- 6 X FLA
AUTO TRANS –> 3-4 X FLA
STAR DELTA –> 3-4 X FLA
The best is VFD – Variable Frequency Drive
We have motor rating in KW, it means KW power take in how much time
Time in sec. Or hour
what is the current rating of 200hp motor?
Full load amp for 200hp approximate = 275 AMP
Approx 245Amp
1. How to calculate stating current of single phase and three phase motor ?
2. How to decide or calculate start capacitor or running capacitor for single phase motor ?
A motor follows the operation as
Load duty cycle
20kW 120 sec
10kW 120 sec
Stopped 280 sec
What will be the continuous rating of motor for above operation.
I have 2 same motor (equal power, rating and brand) 3 Phase, running on same type of job on two different machines, one of them is drawing 45 amps where as other is drawing 50 amps of current. They run 24*7 in plant so i want know is how much unit each one consuming ??
WHAT IS FULL LOAD CURRENT FOR 30 HP 3 PHSAE MOTOR?
Good way of explaining, and pleasant post to take facts regarding my presentation subject matter,
which i am going to convey in college.
i have a dout please help me
when 3 phase supply input it will be rectified ,so the rectified dc power 10kw ,then it will be through on filter so how i can choose the capacitor value and i want proper calculation
in the circuit dc voltage?
current?
filter capacitor value?
capacitor ripple peak current and peak voltage?
any one can solve the problem please reply me-ajeeshaji960@gmail.com
0.37 kw motor Thermal overload setted 1.1 amps
400v 3ph ac 50 hz
motor data
No load current 0.67 amps
Full load amps 1.09 amps
pls explain anybody
what concept on this
What will be the motor load in 3 phase 40 hpmotor runs ons 960 rpm ??
what is the full load amp in given details below..?
1hp motor ,240v rating ?
Please share the ans and detail calculation with pf ?
What could the maximum current and rated current for a motor with following specs:-
3 phase
415 V
11 kW
Sir normally 25hp 3phase motor 440volt. Per kitne amp’s current khapt karta h
Hello. Am a big fan of your precise guidance on this matter.
Please assist me on the calculation of the amperage by considering the Service Factor of the motor.
Service factor is the percentage multiplier that a motor can handle for short periods of time when operating within its normal voltage and frequency tolerance.SF is intended for unpredictable and brief overload conditions, not for continuous operation or intentional short-term overload.
example :
SF 1.15 = 15% more from motor HP/kW
5HP = 3700Watts
SF = 1.15 = 15%
3700 + 15% = 4255W
So the motor will be loaded to 4255W and current consumed in that load is declared as SFA.
240 hp
292 amp
180 kw
415 volt
3 phase induction motor
I now that par phase amp
a 3 phase 15 hp. motor so plz find full load ampere
A 5hp,400v ,3phase motor having 75%efficiency and operating at pf of 0.8 takes a current of ——–A
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