Rotary Phase Converters

Rotary phase converters is an electrical system that changes power from one phase system to another. It is abbreviated as RBC. This power transition occurs via rotatory motion. A single phase power system can be used to produce three-phase power. This is the power that is required to operate three- phase loads. A three-phase load is any appliance that has three phase motors. A single phase power system is used to perform this task in situations where it’s the only available option.


3 Phase Power Operation Principle

A three-phase induction motor usually has three terminals which are called legs. The legs are arbitrarily labeled L1, L2, and L3. Power is applied to a pair of the three-phase induction motor legs. This produces power that is two-thirds of the motor’s horsepower rating. For example, if you apply power to legs L1 and L2, an electric potential is delivered through leg 3. A voltage sag can happen when the load is applied. To prevent this, you can make special windings on the idler. Alternatively, you can use current injection to prevent voltage sag. You should consider power factor correction when making or choosing a rotatory phase converter. A rotatory phase converter with power factor correction uses lesser current than one without. It is also essential to have balanced power between the legs. Unbalanced power can cause damage to the load.


Rotary Phase Converters Types

There are many probable rotatory phase converters designs. It can be built as a motor-generator set. In this design, the load is completely isolated from the single phase supply. This rotatory phase converter produces a balanced three phase output. This model is not used due to its high cost, weight and efficiency issues. The standard design involves building a rotatory phase converter using a three-phase induction motor. This motor is called an idler. Two of the idler’s input terminals are connected to the single phase line. This causes the motor to rotate, and the resulting rotatory flux induces a voltage on the third terminal. This induced voltage is shifted at an angle of 120o from the voltage of the first two terminals. In a three windings system, the first two windings act as the motor while the third winding functions as the generator.


How is your Current Power Quality?

Voltage balance is the major criteria that indicate the quality of power of a rotatory phase converter. Voltage balance is measured when the rotatory phase converter is driving a balanced load. The power quality can also be determined by measuring the Harmonic content of the produced power. The power factor of the rotatory phase converters motor combination also indicates the quality of output. Power quality of a rotatory phase converter depends on the following factors:


  1. The horsepower rating of the idler.
  2. The quantity of power required by the load.
  3. The quality of power demanded by the load.
  4. The technique applied for power balancing between the three plates.


Manufacturing companies use the following techniques in their designs to improve the power quality of a rotatory phase converter,


  1. Use of filters
  2. Capacitors are inserted between the terminals to balance power at a specific load
  3. Idler motors are made with more windings on the third terminal. This is intended to increase the voltage and prevent power sag caused by the load.
  4. They use Idlers with a higher horsepower rating than the load.
  5. Electronics are used to switch in capacitors during startups.


Uses of Rotatory Phase Converters

Three phase motors are preferable to single phase motors. This is because three-phase motors are more efficient and less complex in starting. Availability of 3-phase power also makes them highly preferable. Rotary phase converters are used in electric railways. They produce a single phase power required by the single overhead conductor. Rotatory phase converters converts power phase and the frequency. An example is in countries such as Sweden and Norway where electricity is mainly 3-phase power AC at 50 Hz. Phase converters converts power to a single-phase AC at 25 Hz.

Our Dyna-phase rotatory phase converter is an economical converter. These phase converters are applied in a range of equipment commonly used in your home and workplace. These include grain dryers, refrigerators, air compressors, welding machines, woodworking equipment and CNC machines among others. These converters have been on the market for the last 35 years. You are guaranteed a long-term performance of your equipment when you use these products. When you purchase Dyna-phase products, you are offered a two-year warranty. You are also given a package of replacement parts. You are also free to reach Dyna-phase for any technical advice and queries concerning these components used to convert power.

When you visit their site and company premises, you will be able to see their different Dyna-phase products models. The company is dedicated to giving the best in Rotary Phase Converters. The following are some of the models in the market.


  1. Dyna- phase 1

This is made up of standard duty models. The standard duty models are for equipment with automated controls such as your centrifugal pump, fans, and conveyors. The standard model has controls that make it possible for Dyna-phase to derive power from a single phase supply to a 3-phase motor.


  1. Dyna- phase 2

This is a larger than Dyna-phase 1. It is designed to operate heavier load components than Dyna- phase 1. These equipment include air compressors, submersible pumps, and sealed refrigeration units. The voltage regulated models can operate heavier loads to a maximum of the Dyna-phase plate rating.


  1. Dyna – phase 3

This is a standard duty model which is a multi-motor. It can run up to three times the rating of the largest possible motor. This model is used to operate heavy machines such as woodwork equipment, grain and feeds electronic loads, and machine shop tools.


  1. Dyna-phase 4

This has all the properties of Dyna – Phase 3 but with more improvements. It is used to operate heavier loads such as shearers.


Call Precision Motor Repair CTA



Whatever your industry needs to power up, Precision Motor Repair is approved by the Canadian Standards Association and is ready to serve you. Their licensed electricians and trained staff can provide equipment, service, and repair of your motors, as well as providing 3 phase power options for your business throughout eastern Canada. Their 24/7 customer service line, manned by licensed electricians, is always available to walk you through or trouble shoot any problems.


Located in Leamington Ontario, Precision Motor Repair is looking forward to servicing customers throughout:

  • Halifax
  • St. Johns
  • New Brunswick
  • Nova Scotia
  • Charlotte Town
  • East Coastal Canada


For more information, you can visit our contact page at or feel free to call (519)322-1363 to learn how Precision Motor Repair can improve the functionality and economy of your business or industry by installing rotary
phase converters today.

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