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Our appliances are getting smarter by the day. Its a good thing that many companies are energy conscious and are making their appliance even more energy efficient. In India most of home appliance are now made compulsory to have 5 star energy ratings, especially cooling appliances like ACs , refrigerators.
The TV ads are now flooded with ads talking about inverter based ACs, refrigerators. This is great news for energy conservation. However there is rider to all this. These units are susceptible to damages because of power fluctuations.
A traditional circuit consisted of a step down transformer which converted 230V AC to 24V AC which was then fed to bridge rectifier. The rectifier then converted the AC to DC and then it was distributed to the internal circuits with regulator and other component. Even if the voltage increased dramatically the secondary side would experience a relatively low surge on voltage. Prolonged exposure to voltages might have caused damages to internal circuits. In short these circuits were relatively very sturdy in voltage fluctuations.
However transformer has losses. It dissipates a lot of energy in the form of heat. Even in best cases the efficiency possibly didn’t not go beyond 87%, which was problem. Transfomer is bulky. Higher powered (kVA) machines would require a bigger transformer and as result were heavy too.
What we call inverter technology today , consist of PWM inverters and SMPS based circuits, may be even more advanced. These units have done away with conventional transformer based circuit and in effect increased the efficiency. They are also light weight , very compact and dissipate less energy as heat. They also come in attractive housings
However the flip side is that these circuits are now directly exposed to raw power. This is where the new problems have come up. These circuits are having 20% tolerance to voltage fluctuations. This would mean 180V on lower side and 280V on higher side. Seems ok doesn’t it? Wrong!!!
In developing and underdeveloped countries the power conditions are not so good and voltage frequently goes beyond 350V. This is a curse for these inverter based appliances, which get damaged more frequently than their predecessors.
These circuits are not inherently designed for such conditions and since units are manufactured considering global markets which include EU and US. Many white goods brands have made their foray in a new market only to have marred their reputation by service issues. We have many brands making their disappearing act after blitzkrieg of sales and ads.
One can attribute a serious contribution of such factors on making and breaking of brand in Indian conditions. There is probably two options here, either improve the tolerance of the internal circuits or protect the units externally by use of some protection equipment.
Do let us know what you think.
Author: Amit Manjrekar
(Click the image to learn more about him.)