what is cogging and crawling
Answer Posted / pugezhenthi.p
The cogging effect is the attraction between the magnets and
the stator poles when at rest; this attraction and cogging
is easily felt when trying to turn an electric motor by
hand. The rotor resists the turning, the magnets attempting
to stay bonded to the current poles, until just over halfway
through the air gap, where the attraction to the next pole
is stronger than that of the previous pole, resulting in a
"clunking" or jumping effect at low RPM (such as when trying
to turn by hand). This is the cogging effect, resulting in a
large torque required to begin rotation.
The motor runs at one seventh of the synchronous speed if
the full rated supply voltage is applied is known as
crawling. This is happens because of 7th harmonic induction
torque
| Is This Answer Correct ? | 8 Yes | 6 No |
Post New Answer View All Answers
what is the difference between droop mode and ischnorous mode in thermal powerplant?
1.What is captive power plant? 2.What is national grid?Give brief idea.
HOW DOES THE ELECTRONIC ENERGY METER WORKS?
what is the ms flat constant for calculating earth mat design calculation?
What is the purpose of stand by earth fault protection for transformer ?
why we are not giving the zone 1 trip command to the master trip relay
how the testing of protection CT Testing done through Primary injection kit please describe in detail procedure...
what is the maximum temperature rating of a thhn insulated conductor?
What is mason's gain formula?
Can we use Ccapacitive voltage transformer directly for metering purpose?
Can any one provide the inspection procedure of MIMIC for VFD panel? Details: If someone wants to have a mimic in the VFD panel what are inputs considered for the mimic(like on,off,trip) whether we are able to add speed variation in the mimic(if so how can we get) and what are the parameters to be checked in the MIMIC during inspection?
Any one can explaination about calibration with rotating sub standards?
how we find transformer capacity by ohm
What is the difference between hot and cold loop testing?
how to calculate the power factor when instantaneous voltage and current has harmonics in it ?