Don’t blame the fans for poor performance if you use square wave inverters

Lokesh Pandey, Vice President - (QA)-Havells

With advancement in technology, Fan industry is going through a massive transformation responding to the demands of time and customers. Improving customer experience and creating a feeling of delight are of utmost importance in the priority list of all major fan brands.
The motors of all fans are designed to optimally perform on 230 volts 50Hz single phase A C supply. 50 Hz means Sinusoidal waveform of 50Hz as is received from the mains.
The issue of complaints which have nothing to do with poor quality of fans is often reported by customers who use Square Wave form inverters when the power supply is disrupted. These in expensive inverters are not meant for running appliances like Fans. Some of these deliver very high voltage- up to 350V and high frequency to the tune of 150Hz. This causes big harm to the fan.
Let’s discuss a bit about the two types of Inverters and their Pros and Cons. Square Wave Inverter vs. Sine Wave Inverter

Furthermore, there’s another type of inverter that you can take advantage of:

This one is called “Modified Sine Wave Inverter.” This type of inverter is better than the Square wave inverter and more affordable than the Sine wave inverter though it is strongly recommended that for safety of your costly appliances you should buy Sine Wave Inverters only.

So you get it that when a fan is operated on square/ near square current waveform, they draw more current and hence reduce performance life. Square wave creates jerkily revolving magnetic field, making the rotor to make jerky motion and hence noise. Unfiltered harmonics lead to vibrations in the coil leading to humming noise in fans.

We strongly recommend you to go in for the Sine wave Inverters of a good brand to get the best out of your costly appliances and safeguard them in the long term.