A guide to squirrel cage motors

Figure 1 Squirrel Cage Motor

Figure 1: Squirrel cage motors

The squirrel cage motors hold great power in operating most of our household applications. Manufacturers rely entirely on these electric motors for their notorious features and outcomes. 

True fact:

Squirrel cage motors are cost-saving and reliable, which manufacturers need. This is why these eclectic motors are becoming popular: they optimize production and are low maintenance. These motors are the most commonly used type of electric motors, constituting approximately 90% of industrial motors worldwide.

Let’s discover more! 

Squirrel cage motors: What are they?

Squirrel cage motors are regular induction motors frequently utilized in commercial and industrial situations. These motors work based on electromagnetic induction theory.

These motors are commonly used in domestic and commercial applications such as air conditioners, pumps, and conveyor belts. Their price, dependability, and effectiveness make them famous. 

Squirrel cage motors | Specifications 

Figure 2 3-phase squirrel cage motors specifications

Figure 2: 3-phase squirrel cage motors specifications

The specifications of these motors are what make them stand out. It is due to these specifications that industrialists prefer to use them. Read on, and you’ll know why they hold such a place in the market.

Wide range of power ratings

These motors are compatible with a few watts and a wide range of power ratings. They can cater to diverse applications with diverse megawatts. 

Compatibility with high frequency 

Another specification is that these motors can work with high frequencies. You can operate them on power systems like 230V- 460V AC at frequencies of 50 – 60Hz.

Works on fixed-speed 

For induction motors, the typical speed range for squirrel cage motors is 900–1800 revolutions per minute (RPM), which is a set speed. The power supply frequency affects speed as well. 

High-quality materials

These motors are manufactured using suitable raw materials. Material such as cast iron or aluminum is used for the frame, copper or aluminum is used for windings, and steel is used for rotor and stator cores. It helps to ensure the reliability.

Mounting varieties 

You don’t have to worry about the mounting options because they provide various options. It includes foot-mounted, flange-mounted, or face-mounted options for your ease. With this, you get flexibility for installation in different equipment and machinery.

High protection

Their protection is what makes them stand out. These motors consist of protection features such as 

  • Thermal overload protection
  • Overcurrent protection
  • Voltage surge protection

It helps safeguard the motor from damage due to abnormal operating conditions.

Compliance with international standards

Squirrel motors comply with international standards and regulations from reputable laboratories. It guarantees dependability, safety, and high performance.

What is the squirrel cage motor’s operating principle?

Figure 3 3 phase squirrel cage motor parts

Figure 3: 3 phase squirrel cage motor parts

The stator and rotor in this electric motor create the magnetic field. The magnets are arranged in a circular form around the stator, giving room to the moving magnetic field. 

However, the rotor consists of a cylindrical core made of metal bars or conductors. These bars are arranged in a circle and connected at both ends by metal rings, resembling a squirrel cage wheel.

The working process of the squirrel cage motor is simple. It involves the following steps. 

  • Production of electromagnetic field

This is the crucial part. The stator winding is responsible for creating a magnetic field. It happens when electricity passes through it. Depending on the motor design, the magnetic field can be static or rotation. 

You just need to turn on the motor for a changing magnetic field. An alternating current will pass through the stator winding and change the magnetic field. 

  • Induced current

In the next step, the changing magnetic field caused by the AC through the stator winding induces the current in the metal bars of the rotor. Ultimately, it creates a magnetic field in the rotor as well. 

  • Movement of the rotor

The rotor begins to rotate when the magnetic fields of the stator and rotor collide. The rotor attempts to match the stator’s revolving magnetic field in this way. 

Torque is produced by the rotor by the time it revolves. A conveyor belt or a fan blade are loads driven by the motor’s rotating force. 

  • Efficient production 

The good thing about squirrels is that they don’t need any external electrical connections to the rotor. Producers can boost maintenance and cut expenses because they are easy to use and effective.  

Figure 4 Efficient Production

Differences between induction motor and squirrel cage motor

Both motors might not seem different because of their usage and properties. However, there are minor traits that make them different. 

Let’s explore the differences. 

Starting method

The 3 phase squirrel cage motor typically starts by applying a voltage to the stator windings, creating a rotating magnetic field. An induction motor usually begins by applying a higher voltage or using external devices like starters or soft starters to control the starting current.

Speed control

The frequency of the power supply primarily determines the speed in the squirrel cage motor; hence, speed control is limited. In an induction motor, speed can be controlled by varying the power supply frequency using devices like variable frequency drives (VFDs).

Efficacy of the motors

Generally, squirrel cage motors have lower efficiency than other induction motors due to their simple design. However, induction motors can achieve higher efficiency, especially with advanced features like adjustable speed drives and premium materials.

Use in different industries 

Regarding the applications, squirrel cage motors are one of the machines’ most widely used motors. However, in transportation systems and custom preferences, induction motors are crucial. 

Related reading:

Application Of 3 Phase Induction Motor

Knowing the differences is essential, especially when running your business and looking for efficient, energy-saving products. It is always better to conduct research or approach reliable manufacturers before everything goes in vain. 

Conclusion 

In short, modern manufacturing industries opt for squirrel cage motors for their reliability. These motors remain the core components that provide electricity for various industries.

Businesses demanding the best electric motors can trust Xinnuo Motor for our expertise, support, and best performance. Xinnuo Motor is an outstanding motor manufacturer in China known for its dedication to quality and innovation.  Contact us for services or further information. 

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