What is voltage stabilizer? How does it work?

Voltage stabilizer is an electric device used to automatically maintain a constant voltage level which is safe for home usage when their is a constant fluctuations in the incoming voltage. A voltage stabilizer device acts as a safeguard shield and reduces chances of malfunction by offering a stable voltage output to the load at its output terminals irrespective of any variations in the input terminals i.e. incoming grid or main supply.

Voltage stabilizer

It also helps increase the life of various appliances. Installing a voltage stabilizer is essential to protect expensive electrical appliances such as Air Conditioners, television, refrigerator and computers.

How does voltage stabilizer work?

The basic principle of voltage stabilizer to do buck and boost voltages. It uses different relays to buck down the voltage when it is high and boost up the voltage when it is low. In simple way it balances the voltage.

Ultimately, it tries to maintain the regular 220~240 volts (or whatever voltage is common in your country).

Types of voltage stabilizers.

Voltage stabilizer

There are many types of voltage stabilizer like:

  • Mainline stabilizers.
  • AC stabilizers.
  • Refrigerator stabilizers.
  • TV stabilizers.

Let’s read more about all of them one by one.

1. Mainline stabilizers.

As the word itself self explanatory, mainline, means to be used in mains. Mainline stabilizers are used directly in the mains input and from its output whole load is connected.

Mainline stabilizers are mostly used where voltage is not regulated or where voltage surges is very common like villages or remote areas. That is why people prefer to install mainline stabilizer in their homes to safeguard all the electrical appliances and devices from over and under voltage.

You can find upto 5 KVA mainline stabilizers easily in market and 8 – 10 KVA for too heavy loads.

The mainline stabilizers are costly as it can handle big loads. That is why, unless you need to protect more than 1 load don’t purchase it, instead buy below ones and save some money.

2. AC stabilizers.

AC stabilizers are useful for protecting air conditioners from voltage surge. You must buy stabilizer according to your air conditioner’s capacity. Better consult with your technician for more details.

You can find upto 1.5 – 2 Ton capacity of AC stabilizers in market.

3. Refrigerator stabilizers.

Refrigerator stabilizers are useful for protecting fridge or refrigerator from voltage surge. You should first check your refrigerator first whether it has inbuilt stabilizer or not because most modern day refrigerator comes with inbuilt voltage regulation and surge protection feature.

You can find upto 300 – 450 Liter capacity of Refrigerator stabilizers in market.

4. TV stabilizers.

TV stabilizers are useful for protecting television from voltage surge. Usually it is very compact and can handle small loads of TV and its connected devices like setup box and speakers.

You can find upto 72 Inch capacity of TV stabilizers in market.

Which stabilizer is the best for me?

I will recommend mainline stabilizer in all the cases if you are living in a place where voltage surge is very common, otherwise you must use specific ones line AC, Refrigerator, or TV ones specifically to protect your individual electrical appliance. If you have all in your home then still go with the mainline one as the total cost of all other type of stabilizers will be same as mainline stabilizer.

But before buying mainline stabilizer always calculate the total load in your house. For instance, if your house load is somewhere around 1 KW then it will be safe to choose 2 KVA mainline stabilizer.

Please always buy marginally larger stabilizer as people tend to run everything once in a while.

Drawbacks of using a voltage stabilizer!

There are multiple benefits of using a voltage stabilizer but there is some disadvantage too:

  • It increases the electricity consumption even if you do not use any load.
  • It may do some trickling sound when there is too much of fluctuations.
  • It will be an additional hardware that you need to maintain.

These are some disadvantages that one should consider before opting for it.


Voltage regulation is something has to be done from transformers, but in rural locations due to heavy demand of electricity and many illegal behaviour like electricity theft others has to suffer from voltage spikes and ultimately house owner has to use voltage stabilizers.

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  1. Aulten Avatar

    It was such a required solution before buying any stabilizer according to need of the house. Such an amazing blog .