Our day-to-day lives largely depend on electrical appliances. From microwave ovens and refrigerators to vacuum cleaners and water heaters, life would be incomplete without our electrical appliances.
Electrical appliances find applications not only in homes, but in industries and commercial establishments too. Electrical motors are one of the main components of electrical appliances and their efficiency determines how well the appliance will perform.
It is true that electrical motors consume more electricity than any other type of technology in commercial or industrial applications. But due to advancements in technology, electrical motor manufacturers have designed energy-efficient motors. They have created premium-efficiency motors that use less energy and bring down energy costs.
For those who are new to this subject, the efficiency of an electric motor is determined by the ratio between the shaft output power and the electrical input power. Most electric motors are designed to run at 50 percent to 100 percent of the rated load. The maximum efficiency is ideally near 75 percent of the rated load.
This means an electric motor with 100hp (horsepower) will have an acceptable load range of 50hp to 100hp, with peak efficiency at 75hp. A motor tends to lose its efficiency below 50 percent load or when it is overloaded (since it overheats).
Here are some ways in which you can improve the performance of your electric motors:
1. Eliminate Voltage Unbalance
Voltage unbalance (any deviation in voltage and current waveform from perfect sinusoidal, in terms of magnitude or phase shift is termed as unbalance) between phases will severely impact the operation of an electric motor. The effects of voltage unbalance include:
- Reduction in locked rotor and breakdown torques for the application.
- Reduction in the full load speed.
- Significant unbalance on current, related to specific motor design.
- Voltage unbalance will result in significant increase/decrease operation temperatures.
For optimal performance of the electric motors, it is crucial to eliminate voltage unbalance; it can be achieved in the following ways:
- Single-phase loads should be distributed on the three-phase system so that they put equal load on all the three phases.
- Replace the disturbing equipment (those with unbalanced three-phase reactance) immediately.
- By installing reactive or active filters, you can reduce the harmonics, which significantly reduce the unbalance.
2. Connect Motors to Variable Frequency Drives (VFDs) to Improve Efficiency
VFDs are untapped resources that quickly improve the efficiency of electric motors. A simple and efficient VFD can quickly shift the motor to a point where it reaches optimal efficiency. VFDs are especially effective in applications in which drag is a prominent factor. These include fan systems, air conditioning systems, ventilations, etc.
By using a VFD, the electric motor is able to perform the same task without exerting the usual force that would be required when the VFD is absent. Thus, they make electrical appliances more energy-efficient and are often part of environmental incentive programs, which encourage large organizations using electrical appliances to operate in an environment-friendly manner.
However, to ensure the best output, you need to understand the motor’s specific applications and requirements.
3. Choose Motors in the Right Size
To ensure maximum efficiency, choosing a motor in the right size is crucial. This is especially important for commercial and industrial plants that use huge electrical appliances that consume huge amounts of energy.
Proper evaluation is a necessity as different processes and applications require different types of motors. While some processes can be completed with an old full-load motor, others may require motors that carry less capacity or run slowly. Therefore, determine the type of applications or processes that need to be accomplished and choose a motor accordingly.
Using a slightly oversized motor can be useful for any given application, as it will offer extra capacity whenever needed and will extend the life of the electric motor.
For optimal performance, it is important to ensure that there is little difference between the motor’s potential load and the standard operating load as it ensures that the potential of the motor is not wasted. Thus, you can save money and ensure optimal efficiency within the facility.
4. Proper Maintenance Is a Must
Proper maintenance of electric motors is a must to keep the equipment working optimally. Routine maintenance programs allow technicians to identify motor problems as soon as they arise and fix them quickly. Avoiding maintenance will result in further damage to the various internal parts of the electric motor, thus affecting its efficiency.
Moreover, routine maintenance extends the life of the motor and ensures you do not have to face loss due to downtime or expensive repairs. Technicians can thoroughly inspect every part of the motor and make sure they work optimally, thus improving the performance of the motor.
The performance of an electric motor depends on its efficiency, so you must have a plan to improve the motor’s overall efficiency.
Evaluating the processes/applications and using the right kind of motors can get the tasks accomplished quickly and efficiently. Proper maintenance of motors is crucial to ensure that the problems are identified as soon as they arise and so is implementing repairs/replacements as and when needed to ensure the motor works optimally.
Keeping the phase voltages equal or close to equal works well in making sure the electric motor works with full efficiency. Voltage unbalance not only affects the performance, but also shortens the motor’s life.
By keeping the above points in mind, you can improve the performance of an electric motor, whether at home or work, and make life easier.
image credit: regalbeloit.com