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Squirrel Cage Induction motors are cheaper in cost compared to Slip Ring Induction motors. Requires less maintenance and rugged construction. Because of the absence of slip rings, brushes maintenance duration and cost associated with the wear and tear of brushes are minimized.
What are the advantages of squirrel cage induction motors?
Advantages of Squirrel Cage Induction Motor They are low cost. Require less maintenance (as there are no slip rings or brushes) Good speed regulation (they are able to maintain a constant speed) High efficiency in converting electrical energy to mechanical energy (while running, not during startup)Aug 19, 2020.
What are the advantages and disadvantages of slip ring induction motor over squirrel cage induction motor?
Induction motors generally will have low starting torque compared to dc series motor. Slip ring induction motor have big advantage of having high starting torque compared to squirrel cage motor. Therefore slip ring induction motors are generally employed where load requires high starting torque or good speed control.
What are the advantages and disadvantages of wound rotor over squirrel cage rotor in induction motor?
As a result the inrush current is reduced. Another important advantage over squirrel-cage motors is higher starting torque. The speed and torque characteristics of a wound-rotor motor can be adjusted by changing the external resistance, unlike a squirrel cage motor which has a fixed characteristic.
What is the difference between squirrel cage motor and induction motor?
Key Differences Between Slip Ring & Squirrel Cage Induction Motor. The motor whose rotor is wound type such type of motor is called slip ring induction motor, whereas the squirrel cage motor, has a squirrel cage type rotor. The starting torque of the slip-ring motor is high, whereas in squirrel cage motor it is low.
What are the disadvantages of squirrel cage induction motor?
Main disadvantage of squirrel cage induction motor is that they have poor starting torque and high starting currents. Starting torque will be in the order of 1.5 to 2 times the full load torque and starting current is as high as 5 to 9 times the full load current.
What are the disadvantages of squirrel cage motor?
Disadvantages of squirrel cage induction motor : Poor starting torque. High starting current. Speed control is not possible in a squirrel cage induction motor., in short, no speed regulation. Sensitive to change in supply voltage. More sensitive to the supply voltage regulation fluctuations.
What are the advantages of slip system?
The advantages of this system are: ADVERTISEMENTS: (i) it reduces the possibility of errors and frauds; (ii) it saves a lot of time since it is prepared by the customers themselves; (iii) it provides a good system of internal check etc.
Why the starting torque of squirrel cage induction motor is low?
It suffers from the disadvantage of a low starting torque. It is because the rotor bars are permanently short-circuited and it is not possible to add any external resistance to the rotor circuit to have a large starting torque.
Why slip ring motors are noisier that squirrel cage induction motors?
Answer. The wound rotor has the facility of increasing the rotor resistance through slip rings. High value of rotor resistance is needed during starting to get a high value of starting torque. Q:What are the advantages of slip ring motor over squirrel cage motor?Mar 7, 2018.
What are the advantages of wound rotor over squirrel cage?
The wound-rotor motors have the following advantages over the squirrel cage motors : (i) High starting torque and low starting current. (ii) Smooth acceleration under heavy load. (iii) No abnormal heating during starting.
What is the difference between squirrel cage and wound rotor?
Difference squirrel cage rotor and wound or slip cage rotor This rotor is in the form of bars which are shorted at the end with the help of end rings. In squirrel cage rotor no slip rings or brushes. In wound or slip rotor slip rings and brushes are used. It has a simple construction.
Why rotor slots are skewed?
The rotor or stator slot of the induction motor skewed through some angle so that the bars lie under alternate harmonic poles of the same polarity or other words, bars must be skewed through two pitches. The main purpose of skewing is to reduce the magnetic logging between the starter and the rotor.
What is the principle of squirrel cage induction motor?
Squirrel induction motor working is based on the principle of electromagnetism. When the stator winding is supplied with a three-phase AC, it produces a rotating magnetic field (RMF) which has a speed called synchronous speed. This RMF causes voltage induced in the rotor bars.
Why is it called squirrel cage motor?
Squirrel cage motors are a subclass of induction motors, which harness electromagnetism to generate motion. They are so-called “squirrel cage” motors because the shape of their rotor – the inner component connected to the output shaft – looks like a cage.
What is the purpose of squirrel cage?
The main use of a squirrel-cage motor in a home HVAC system is that it powers the blower fan. If you have a forced-air heating system, such as a furnace, and/or an air conditioning system, the squirrel-cage motor is the part that turns the fans that blows the heated and cooled air through the ventilation system.
Why is the speed of the squirrel cage motor fixed?
‘Fixed’ speed induction generators Because the speed variation from no load to full load is very small, the term ‘fixed’ speed tends to be widely used. The design and construction of the stator and rotor of an induction generator are similar to that of a large induction motor having a squirrel-cage rotor.
Which Motors has high starting torque?
Series wound DC motors are best for applications that require high startup torque, without the need for speed regulation. Like a shunt motor, as a load is applied to a DC series motor, the motor speed decreases, which reduces the back EMF and increases the net voltage.
Why is the squirrel-cage induction motor one of the most reliable machines used in industry?
Three-phase squirrel-cage induction motors are widely used as industrial drives because they are self-starting, reliable and economical. VFDs offer especially important energy savings opportunities for existing and prospective induction motors in variable-torque centrifugal fan, pump and compressor load applications.
How can we increase the starting torque of squirrel cage induction motor?
There were many attempts to design the rotor bar shape to increase the starting torque in squirrel cage induction motor, and it is well known that deep slot of rotor bar increases the starting torque. However, this deep slot increases the leakage flux so that it hurts the running efficiencies.
Which motor is usually preferred for the elevator nowadays?
AC slip ring or DC compound motors are prefer for lifts. Shunt type commutator motors are preferred in case of single phase installation. The latest lift designs use 3-phase induction motors with variable frequency drive electronic controls.
