Many shop tools and machines run on three-phase energy, but the energy company only supplies single-phase energy! One problem that many new mechanics and shop owners run into is how to power all that equipment.
There is a solution! A phase converter can transform that two-phase current into the three-phase energy that you need to power your shop.
Do you need to purchase a phase converter for your business? Read on for all you need to know about phase converters and how to choose the right one for your needs.
What Is a Phase Converter?
First, let’s talk about phases.
Most energy in the United States is produced as single-phase electric power. This is the distribution of alternating current or AC electric power.
A phase converter takes the single-phase distribution and converts it into a three-phase electric power source. This allows commercial and industrial applications to be used safely.
What Kinds of Phase Converters are on the Market?
There are three main types of phase converters: rotary phase converters, static phase converters, and sine wave inverters. The most commonly used converter is the rotary type. Read on for more detail about each type of converter.

Static Phase Converters
A static phase converter works by powering up a three-phase induction motor using motor capacitators. The capacitators use a single-phase electric source to get the motor up to its full RPM, then they are disconnected. The motor continues to run on the single-phase source.
Rotary Phase Converters

A rotary phase converter has two components: an idle generator and a control panel. The idle generator is powered by a single-phase current that rotates a mass. The rotating mass generates a third line of power which is added to the two waves of single-phase current.
There are three types of rotary phase converters.
The first is a standard rotary phase converter. This converter couples an idle generator with a digital control panel.

A digital rotary phase converter is the second type. This converter also has a digital control panel, with the addition of a digital boost and voltage balancing control.
Rotary converter panels (Figure 3)provide the digital converter panel. The buyer would supply the idle converter.
Sine Wave Inverter
An inverter is a mechanism that changes direct current (DC) power to alternating current (AC) power. DC power is the kind of energy generated from a battery. AC power is what we get from a wall outlet.
A sine wave inverter can be hooked up to a battery. It will take the energy and change it to a three-phase alternating current. This phase converter allows you to operate tools even when you’re not hooked up to an outlet.
What Kind of Phase Converter Should You Choose?
While there are three main types of phase converter, there are many different kinds of each. Some are designed for light power loads, while others may fulfill different requirements. These simple steps will help you choose the right size phase converter for your needs:
- List Your Equipment and Power Needed
Make a detailed list of all the equipment you need to convert. The type of machine, the type of power it requires (watts, kilowatts, amperes, etc.), and the amount of power it needs. Total everything up.
The phase converter you choose should exceed the amount of power that all your equipment currently needs. You may also need to think about starting power versus running power. Some machinery uses more power to start up than to keep running.
It’s better to choose a bigger phase converter than you think you need. If you don’t, you may find you need to purchase another one in the future.
- Think About Your Shop Setup
How you have your shop setup will affect the kind of phase converter you need. For example, you may need to power multiple machines. Or you might need a portable phase converter to move it between machines. Your shop design will be a factor in your phase converter choice.
- Plan On Double
The rule of thumb when planning what size of phase converter to buy is to double the horsepower (HP) needed by your machinery. For example, if you need 50 HP to power your three-phase energy machines, buy a 100 HP phase converter. This is because the start load of machinery.
Start load refers to the amount of power needed to start up a motor. Run load is the amount of power it takes to keep running evenly. Start load is often double the amount of voltage of a run load.
- Get Advice
You know your tools, but you might not know everything about electricity. An electrician or shop supply company will be able to help guide you in making an educated choice about a phase converter.
Once you’ve listed out the power you need and done your research, take your list to a local expert.
Get Your Shop Up and Running!
If you’re setting up a new shop, do not forget about phase converters. These devices are essential to getting your business powered. Get expert advice about how to choose the right phase converter for your shop’s needs.