Does a fridge need a pure sine wave inverter?

By Matthew Joseph Nandirio •  Updated: 09/27/21 •  6 min read

A pure sine wave inverter converts direct current to usable alternating current. In simple words, if you have a solar system, a pure sine inverter can convert that power for functional electrical appliances.  Moreover, just like a power grid, it maintains a smooth and steady voltage.

In fact, the durability of the fridge partially depends on the consistent supply of power. Power fluctuation can damage the internal mechanism of the system. Hence, power inverters are fundamental for the smooth functioning of the fridge.

Solar Inverter
Solar Inverter

Let us first understand the mechanism of a pure sine wave inverter. Then, I will also explain why it is important to use a pure sine wave inverter.

Understanding pure sine wave inverter

Pure sine wave inverter doesn’t hold any electromagnetic pollution. Moreover, it generates high efficiency and consistent sine wave output. In addition, the output of AC power is far better than the regular power grid.


It also produces a high-frequency technology perfectly fitted for diverse electrical appliances, including a fridge. It is important to note that electrical appliances like refrigerators are very sensitive. 

Hence, it demands to be treated delicately. Excessive frequencies of power supply can damage the internal electrical surfaces.

In a nutshell, pure sine wave inverters are the ideal choice for your refrigerator for the following reason:

  • It provides high-quality Alternative Current
  • It can drive any kind of resistive load
  • Finally, a pure sine wave inverter has the highest conversion efficiency

However, on the downside, they have higher technical requirements. Henceforth, it costs quite high than modified sine wave inverters.

What are the other alternatives of inverter for your fridge?

 Everyone out there might not have the economic strength to install a pure sine inverter. In that case, how would you protect sensitive home appliances? I have an alternative suggestion for you!

Based on the waveform, inverters can be distinguished into two types.

  • Pure sine wave inverter
  • Modified sine wave inverter

While the former is the clear choice for your fridge, the latter also has some potential qualities. So, let us now understand what is modified sine inverter is all about?

Understanding modified sine wave inverter

As the name suggests, it modifies the sine wave. More precisely, it pauses the output waveforms between the range of maximum positive and negative values. Moreover, it increases the user effect of the power generation.

However, if you are using a modified sine wave inverter, you should avoid inductive power loads. So, what’s this inductive load means? It refers to high-power electrical appliances. Moreover, these products need to be run through the principle of electromagnetic induction. Devices like motors, compressors, fluorescent lamps require a larger start-up current.

If a fridge requires 150 watts of power for regular operation, you need to start the operation that is more than 1000 watts. It is very important to note that consistent overload of inverters can impact the service life of the inverters.

In the exceptional case, when the power quality is moderate, modified sine wave power inverters can fit into the position. However, the disadvantages of the sine wave inverter show, it has 20% harmonic distortion.

Hence, there might be some difficulties and issues to smooth out the operation. Moreover, it can result in high-frequency inference. You compromise this inconvenience for a lower price. The choice is yours!

Apart from these two, there is another choice of inverter for your refrigerator.

Square wave inverter

The square wave produces severe instability in power. Square wave inverter generates poor quality AC current. Moreover, the capacity of power ranges from maximum positive to maximum negative. Hence, it has a poor load capacity. To b more precise, the load capacity ranges from 40-60%.

Unfortunately, they cannot carry an inductive load. Moreover, the excessive load also generates a third harmonic component to increase the capacity of power flow. Often, it can seriously damage the internal circuits due to high power fluctuation.

Due to its contrasting inconvenience, it is nearly obliterated from the market.

Tips for running a fridge on inverters

  • Always buy an energy-efficient fridge. Even though the new-age refrigerators are potential energy complaints, take your time to compare 3-4 models.
  • Like a fridge, it is also important to buy a good quality inverter. Consider purchasing a potential surge watt capacity.
  • It is ideal not to run the inverter at the maximum capacity. Remember, an inverter is capable of handling the watt frequencies for a few seconds only.
  • Make sure to calculate the power usage. If you are running two or more products on an inverter, consider calculating the power usage.

Final Say

You see, there is no better choice than a pure sine wave inverter for your fridge. It not only protects home appliances from internal damage but also improve their self-life. It is more efficient than a modified sine wave. 

A typical refrigerator consumes a considerable amount of energy. Hence, it is very crucial to install a high energy efficient inverter. Fortunately, pure sine can produce more than 30% watt than a modified sine wave.

The key to running a refrigerator on the inverter is to make sure there is enough surge for watt capacity.

People also asked:

Does a refrigerator need pure sine wave?

A refrigerator is a delicate electrical appliance. Hence, consistent power flow with high-efficiency voltage is essential for refrigerators. If you want to protect the fridge from any internal circuit damage, a pure sine wave refrigerator is the best option for you.

What type of inverter do I need for a refrigerator?

While considering the best inverter for your fridge, two things come to mind. One is price, and the second is durability. IF YOU ARE CONCERNED ABOUT THE DURABILITY, YOU HAVE TO GO FOR A PURE SINE WAVE INVERTER. However, IF YOU WANT O NEGOTIATE WITH QUALITY OVER PRICE, THEN CHOOSE MODIFIED SINE INVERTER.

Can you run a fridge off a modified sine wave inverter?

YES, YOU CAN! EVEN THOUGH IT DOESN’T HAVE THE CAPACITY TO PRODUCE HIGH-EFFICIENCY ENERGY, IT IS A WISE ALTERNATIVE. Modified sine wave inverters protect your sensitive devices from high power fluctuation.

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Matthew Joseph Nandirio

Matthew Joseph Nandirio is the Founder of walkingsolar. After graduating from the University of Houston in 2002, matt started working as an electrical and electronic engineer for several multi-national solar energy companies. He has a wide range of experiences including solar system requirement analysis, planning, maintaining, debugging and even solar device development through research. He now shares his 20 years of expertise through his articles on the walkingsolar website. Further, he is also the author of two books on Solar Technology, “Solar Power for Villages” and “DIY Solar System for Dummies”.