Frequency converters or changers are devices that convert about 50-60 Hz of incoming power to 400Hz output power. They come mainly in two types- rotary and solid state frequency converters.

The rotary frequency converters run motors on electrical energy while solid state frequency changers convert alternating current to direct current.

What they do

It’s a known fact that alternating current is the standard utility power used today. It’s basically the number of cycles positive and negative power fluctuates around a neutral datum that exists in two standards around the world, 50 and 60 hertz.

It’s 50Hz in European and Asian countries and 60 Hz in North America. While there’s no advantage between the two, things grow disadvantageous when the load being powered depends on the input power frequency because motors spin in multiples of the power frequency.

This means that 60Hz motors spin at 1800 or 3600 RPM while 50 Hz motors spin at 1500 or 3000 RPM. With machines being speed sensitive, they require power matching their intended RPM design.

So European machines needing 50 Hz input require a 60-to-50 Hz frequency converter to function in the United States while American machines needing 60 Hz input require a 50-to-60 Hz frequency converter to run in Europe.

Some exclusions

Frequency converters are needed to ensure the motor spins according to the motor’s original rotational design. However, there is some equipment like resistance heaters and some lights that function on resistive loads that do not depend on the incoming power’s frequency.

As long as the voltage is right, this equipment does not require frequency conversions or changers to work. However it’s cheaper if you divide the load into two parts and use a converter to feed the frequency-dependent part even if a major part of the equipment’s load is resistive.

Sometimes it even works out cheaper for a company to replace the motors of the load to proper frequency motors instead of investing in frequency converters.

This shows that, like any electrical product, there’s no common rule to follow when it comes to buying frequency converters. You have to choose and invest in one based on your establishment’s power needs.