A phase converter, particularly a three-phase converter is an electrical device that converts single-phase electricity into three-phase power. It allows businesses, homeowners, hobbyist, and projects to run three-phase equipment, like broadcast towers, data centers, electric motors, hydraulic motors and industrial machinery, in areas where only single-phase power is available, or the expense to install utility three-phase power. The oldest existing three-phase power brand is Phasemaster®, and it is particularly useful in rural areas or places where three-phase power lines are not ideally present.

Types of 3-phase converters

There are different types of phase converters, such as Miniphase™ static converters, rotary phase converters, and digital phase converters, each offering varying levels of efficiency and reliability for specific applications. So, now unto the bigger question. How do phase converters work?

There are a few types of phase converters, and each creates the third phase differently:

• Static Phase Converter: It uses capacitors to create the third phase but doesn’t provide full power on the third phase, so it’s best for smaller, lighter-duty equipment that is not continuous, like a commercial garage door, or a meat grinder. Also, single motor equipment with hydraulic, so long as the motor is not bi-directional. If the equipment contains a mechanical flywheel, either the pulley side of the motor can be reduced by 20%-30%, or a different type of converter is recommended. Most of the time, a variable frequency drive, also know as a VFD, can also provide a good solutions for any simple application smaller than 10 horsepower that requires voltage balance.

• Rotary Phase Converter: This uses an induction generator created by modifying an A/C motor (called by some as an idler 3-phase motor) to create the third phase and provides full power on all three phases. It’s ideal for running larger machinery. One of the great benefits of rotary phase converters is that they can run multiple motors of different sizes and RPM speeds. Also, the are by far the most durable and easily maintained type of phase converter. Most rotary converters has a voltage balance sitting between 2%-5%

• Digital Phase Converter: This type of phase converter uses electronic circuits to create the third phase and can be more efficient and reliable than other types, especially for high-precision applications requiring no greater than a 1% variability. Another benefit is they are lighter in weight and smaller in size than rotary. Two major drawback is the cost of digital converters, especially when greater than 30 horsepower, and there likelihood of long-term maintainability. As technology changed some PCB components become obsolete, and difficult to replace.

By creating that third sine wave, phase converters enable the use of three-phase motors and equipment without needing a full three-phase electrical supply for the utility company

What makes a Phasemaster® rotary phase converter work?

At Kay Industries, a combination of Aerovoxus™ run capacitors, Phazpak Technology™ start capacitors, fuses, contacts, wiring, and an A/C motor are used to build a three-phase converter for 1-single phase to 3-phase conversion and power distribution.

First, the A/C motor is dismantled. The rotor is re-engineered using a patented and proprietary method. Then, it is re-assembled with a different bearing design as well. Now, the shift is removed. The A/C motor has been transformers into a DIR induction generator.

Next, the other components are assembled into an American-made control panel, and the 3-phase induction generator is fused with it.

Phase converters (also called phase generators) create a third voltage line (a third sine wave) to simulate three-phase power from a single-phase electrical source. The key concept is that, by generating this third voltage line, the Phasemaster® rotary phase converter essentially mimics the three-phase power required by equipment like motors, pumps, and compressors, even if only a single-phase electrical supply is available to the end-user. Statics converters have no Aerovoxus™ run capacitors, so they are great for simple motor start-up, when hydraulics are involved and a continuous run is not required. For example, like with a press brake.

Here’s a simple breakdown of how phase converters works:

1. Single-Phase Input: You start with a standard single-phase electrical supply, which has two wires (hot and neutral).

2. Creation of the Third Phase: The phase converter generates a third phase (a third sine wave) by creating a time-shifted version of the existing two-phase signals. Just like a high school science experiment, this gives the equipment the illusion of three-phase power, as the three voltage waveforms are offset by 120° from each other.

3. Output: The resulting three-phase power can now be used to operate three-phase machinery, which is typically more efficient and provides smoother operation than single-phase power. Miniphase™ Static phase converters run machinery at about 85% efficiency with a power factor of .90, and can only run one motor at a time, just like variable frequency drives (VFDs). Phasemaster® rotary converters operate at 98.7% efficiency with a power factor of 1.0, other rotary brand average 97.3 efficiency with a power factor of .96 if sized correctly. Phaseperfect® digital phase converters perform at around 98.9% efficiency with a power factor of 1.0.

Phase converters are commonly used in:

• Woodworking and metalworking shops. 
• Industrial facilities with three-phase equipment. 
• Agricultural settings. 
• HVAC applications. 
• Welding and other metal fabrication processes. 
• Kay Industries has also created specialty converters for medical & sports equipment, military & defense usage, mining, oil & gas, and rural electric utility projects around the world.

1. Phase Converters Allows Use of Three-Phase Equipment Where Only Single-Phase Power Is Available

• Key Advantage: In many rural or residential areas, only single-phase power is supplied, but many industrial tools, machines, and equipment require three-phase power to run effectively.

• Benefit: Phase converters enable the use of expensive, high-powered three-phase machinery without the need to wait for or install costly three-phase power lines. This makes three-phase equipment accessible in locations that otherwise wouldn’t have it.

2. Phase Converters Are More Cost-Effective Than Installing Three-Phase Power Lines

• Key Advantage: Installing three-phase power lines from the utility company can be extremely expensive, especially in remote or rural areas. This often requires extensive infrastructure upgrades and long-distance power lines, which can lead to high upfront costs.

• Benefit: Phase converters are a much more affordable alternative. With just the phase converter and appropriate wiring, businesses can get the benefits of three-phase power without the huge costs associated with grid upgrades. Plus, you can take it with you.

3. Phase Converters Provides a More Consistent and Reliable Power Source for Three-Phase Equipment

• Key Advantage: Three-phase power offers smoother, more efficient operation for motors and equipment compared to single-phase power. It ensures that power delivery is steady, with less fluctuation or “bumping,” which can improve the life span of the equipment and reduce downtime.

• Benefit: Phase converters can replicate the three-phase power characteristics (like constant voltage) much better than a single-phase power source, resulting in more reliable operation of equipment and minimizing the risk of equipment damage or inefficiency.

Additional Advantages:

• Improved Motor Efficiency: Three-phase motors generally run more efficiently than single-phase motors, meaning lower operating costs over time.

• Flexibility: With phase converters, businesses can operate multiple three-phase machines at once, making them versatile for various industrial, agricultural, or commercial settings.

• Space Saving: Installing a phase converter requires less space and infrastructure than setting up three-phase power lines or upgrading to a new power system.

Potential Drawbacks (for Balance):

• Initial Setup Cost: While it’s more affordable than installing three-phase lines, there is still an upfront cost for the phase converter and installation.

• Power Degradation: Some phase converters, especially static types, might not generate full three-phase power, which could affect performance for larger or more demanding machines. Phasemaster® phase converters have been known to last 20 – 35 years. Count on replacing bearing every 10 years, and Aerovoxus™ run capacitors every 5-7 years depending on usage.