Answer / anil

d.c. series motor

bcoz its starting torque is high and also speed is inversly
proportional 2 load

Answer / milinda4p

Ok..I have gone through a training in a port and I found out
that in large cranes(ex: Quay cranes) most of the time for
Hoisting loads DC series motors are used(IMPSA). But as it
has several maintainence to be done frequently ( ex:
Commutator replacements etc.) and the emerging technology of
power electronics newer quay cranes (ex: ZPMC) are using
Squirrel cage induction motors.
But there arn't any wound rotor induction motors used
probably due to higher costs.

Except the hoists in other functions such as Gantry travel,
Trolley travel, Boom hoist etc Always Squirrel cage
induction motors are used

Answer / nisha

synchronous motor coupled with variable frequecy drive

Answer / biki

Ac Slip Ring Motor

Answer / indi

slip ring induction motor

Answer / milinda4p

Biki: AC slip ring motor?? I think you mean wound rotor
induction motor as it is the only AC motor which has slip rings?
Biswa: Normally squirrel cage rotors are made of two copper
rings connected by copper bars. So how to make it high
resistive?

Answer / mounica

squirrel cage induction motor

Answer / k.prakashchandra

Rotor wound motors.

Answer / biswa

in addition to milinda i would like to ad one more things
that for cranes application squirrel cage induction motor
uses high resistive rotor bar to provide high starting
torque compromising the extra loss.

what is ups Paralleling? how is load sharing at that time ? what are the things we have to note that time?

1 Answers  

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