Answer / sri

If the motor is in idle condition and if u want to start
the motor and rotate it will give u a humming noise only
and will not rotate.But if it is already in running
condition and suddenly if it happens to run in the two
phase it will run ,and gradually it will get over heated
and at one stage it will trip or burn

Answer / ram kumar

yes

Answer / deependra shakya

Yes a three phase Induction motor can run by 2 phase.

Answer / jessy

Suppose 3 phase induction motor is running but if one phase
trips, it will continue to run but at reduced torque -
jessy

Answer / kandavel

yes, If the motor is in idle condition and if u want to
start
the motor and rotate it will give u a humming noise only
and will not rotate.But if it is already in running
condition and suddenly if it happens to run in the two
phase it will run ,and gradually it will get over heated
and at one stage it will trip or burn

Answer / ram

Yes possible. Using capacitors you can run three phase
induction motors with high current rating. Normal current
rating is 1.5 amphere per HP for each phase;but for two
phase it will go up to 2.0 to 2.5 amphere for each phase.

Method: You can use running capacitors with 440 rating.For 1
Hp you need 12- 15 mfd capacitor/for 5 HP you need 60-70
mfd.You can make new phase via this capacitor from any one
of the remaining phases, if motor runs in reverse connect
capacitor in the other phase. For starting you may have to
add additional 100 mfd in parallel with the capacitor
previously described via make break switch of suitable
current rating for a moment.

Answer / sandip

Yes,But in Lower Efficiency

Answer / dum

but sri, i have one experience, the motor was in idle
condition. but with only 2 phases it rotated. can anybody
explain how a rotating magnetic field is created when there
is only 2 phases

Answer / gunasekaran

IT will rotate because due to the phase displacement B/w
two phases so average value is no zero for two phase
circuit so torque will produce. at the same time it is not
running full speed and it draw around two times current
from sys so wdg of another two phase getting heated up if
it small motor OLR will give trip if it big one negative
sequence giving trip comment

Answer / bhasheer

only two phase will never create rmf in three phase motor... we need a capacitor to create three phase rmf. while using the capacitor the motor starts to rotate but the starting torque will reduces....



During the normal running condition of three phase motor, if one phase fails, the motor will run continuously when there is no load in the shaft.


At the same time if the motor is connected through the starter,the over load relay in the starter trips and the motor will stops....

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