Is a induction motor rotate by back emf ? If not , then how it is rotate ?
Answer Posted / chandru
Yes,back emf should be there to run it as an induction
motor.Normally what will happen is, when you give 3 phase
power to stator,rotating magnetic field(rmf) will be
created over it.Inturn,this rmf will induce an emf in rotor
side.According to lenz law,obviously this induced emf will
oppose the cause that produces it.Here, the cause is
relative motion between stator's rotating mag field and
rotor speed.Normally,we will call it as slip.So, it will
try to make that relative motion to zero.Due to this
operation, induction motor will rotate.If suppose,rotor
speed catches the stator's rmf,induction motor will
stop.Finally, the main thing to note here is that, it wont
run without slip.
| Is This Answer Correct ? | 3 Yes | 1 No |
Post New Answer View All Answers
(1)Can earth and be conected together (2) what is the diferent between earth & neutral
what about the power of wattmeter at starting and loding?
what will happen if multimeter(selector switch at DC voltage) and terminal at current is connected to DC supply?
why we testing the core balance of the transformer before comissioning?
what is the ms flat constant for calculating earth mat design calculation?
Why we are use dol starter up to 10 hp
HELLO EVERYONE, I RECENTLY HAVE FOUND ONE PROBLEM, I WAS TAKING NO LOAD TRIAL OF AN HT MOTOR 920 MOTOR , 1440 RPM , 6.6 KV, WITH AUTO TRANSFORMER. AT 450 V, LOAD WAS 40 AMP AND SPEED WAS 250 RPM. BUT AS WE INCREASE VOLTAGE FROM 450 TO 480V, LOAD BECOME 41 AND SPEED REDUCED TO SOME RPM . SO WHICH PHENOMENON ACTED HERE FOR REDUCING SPEED.?? AND IS IT HAPPENING ALWAYS OR IT IS RARE? I ALSO HAVE FACED SUCH PROBLEM WITH FEW LT MOTOR ALSO.
Is it required to lay 2 runs of GI wires along with armoured cables from one power DB Machines of higher rating?
Is there any guideline say about display of earthing value near to earth pit
Power factor =1.000 at factory in supply. However, PF = 0.8 at motor end. Current = 100 Amp, Voltage = 400 V. What is the power distribution loss? Can I reduce it by adding capacitor at the load feeder?
What is the transfer function?
WHAT IS MEANT BY DERATING OF THYRISTOR?
Why frame of the motor is specified?. If we mention KW and voltage level,automatically frame is decided or separately frame is compulsory to mention?.
please send me the L&T Emb. sys. placement papers and entire details of pattren
we have 3.5MVA-11/6KV transformer. how can we calculate earth fault current and NGR calculation?