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General Information about phase converters:

Rotary Phase Converters these much more sophisticated units create true three phase power supply, often more precise than utility-supplied three phase power.

Who can use a Rotary Phase Converter?

Rotary phase converters are most commonly used in commercial, industrial, and residential settings to power three phase equipment when utility 3-phase power is either too costly or not available. Rotary phase converters convert single-phase power into balanced three-phase power. Rotary phase converters are a very cost-effective way to power three-phase CNC equipment, and they come with simple and easy to use installation manuals. Rotary phase converters are rated using the maximum horsepower that they can handle. Due to the consistent voltage balance, the electric motor will operate at or near its full horsepower capacity. The output is custom balanced to meet the requirements of CNC equipment as well as other loads.

How do I size a phase converter?

Determine what equipment you will be running and look at the Full Load Amp (FLA) rating or Service Factor Amp (SFA) rating. You can run multiple loads simultaneously as long as the total amp draw of all pieces of equipment is less than the rated output of the phase converter.

How much electricity does a phase converter use?

A rotary phase converter, by itself, is in an idle state and draws only the amount needed to keep it energized. This is only a few kilowatts and in some cases is less than a kilowatt. Your true electrical consumption is based on what the load draws. The rotary phase converter is merely a device electricity passes through on its way to your load.

Can I run a 480 volt piece of equipment on an American Rotary phase converter if my single phase voltage is 240?

Yes, however, a transformer is also needed. A rotary phase converter produces a three phase voltage identical to its input voltage. For example, if your input is 240 volts single phase, then your output is 240 volts three phase. The rotary converter does not change voltages. In this case, a step up 3 phase transformer (240 volt to 480 volt) is needed after the phase converter.

What type of maintenance is required for a rotary phase converter?

An American Rotary phase converter is very dependable!

Please check the following annually:
1) Keep dust and moisture away from the control panel and the idler. Keep dust from accumulating in the motor. Dust can be blown out using compressed air. Keep dust from accumulating on the surface of a TEFC idler as this prohibits proper cooling.
2) Please check all lugs and make sure nuts are torqued down. The nut on the lugs pem studs should be torqued down to 87 in/lbs using a calibrated torque wrench.
3) Check all connections to capacitors to make sure nothing is loose and all terminals are fully on the capacitors.
4) Check all input and output connections and make sure the lugs are tightened and secure.
5) Check all connections to the idler and make sure all electrical tape is secure.
All connections should be done with wire bolts and nuts. Insulate all connections made in the idler junction box using rubber mastic tape, heat shrink tubing, or standard electrical tape.
6) Bearing grease may occasionally be needed.

How large of a single phase service do I need?

Your single phase service required is dependent on the loads connected after the phase converter. American Rotary phase converters will run on a range of input amperage. As a general rule, determine your 3 phase load amps and double for your single phase feeder amps.

What else do I need with a rotary phase converter?

Generally speaking, you will need wire, conduit, connectors and a single phase power source, such as a circuit breaker or disconnect switch. More materials may be needed depending on how elaborate your output connection is between the load and phase converter. American Rotary offers a full line of electrical components to make your installation easy, professional, and safe.

What does CNC mean? Can an American Rotary Phase Converter run a CNC machine?

CNC stands for Computer Numerical Control. CNC equipment has a computer that can be programmed to run the operation of the machine. Computer operated machines are generally very voltage sensitive. The American Rotary Smart Series Rotary Phase Converter has +/-5% voltage balance to run these types of machines.

Will my machine lose power running on a rotary phase converter?

Absolutely not, provided the rotary phase converter is sized correctly. Our Micro-Smart controller generates a balanced three phase output allowing your equipment to furnish full rated power.

Will my utility company approve of an American Rotary Phase Converter?

Most utility companies will recommend the use of a rotary phase converter. In fact, it is much more cost favorable compared to installing 3-phase power lines. With the American Rotary/Baldor induction generator and American Rotary’s Variable Impedence Technology (VIT), utility companies prefer the American Rotary converter because it use 1/3 of the current at start up compared to other phase converters.

Is there a US standards organization specifically for phase converters?

The truthful answer is no!”  The only organizations we are aware of and adhere to are UL (Underwriters Laboratories) and the N.E.C.(National Electric Code) Article 455. These are the organizations and standards that American Rotary Phase Converters follows.

What is the difference between a phase converter and a variable frequency drive (VFD)?

Phase converters provide three-phase, 60 Hz power like what a utility would provide and can be used to power machines that have internal electronics that control motor speed. Variable frequency drives are used to vary the speed of electric motors.

Why are my lights flickering when the equipment is running and how do I remedy it?

This phenomenon is called electromagnetic interference (EMI) and is typically caused by poor grounding or wire routing. A poor electrical ground doesn’t allow high frequency noise to easily travel to ground, causing interference on other circuits. Additionally, if power lines are routed near adjacent wiring, high frequency noise can be radiated onto nearby wires. causing interference. An EMI filter can sometimes eliminate EMI but the ideal method is to address grounding and wiring issues.

Why would I choose an American Rotary phase converter over a solid state digital converter or static converter?

There are two main reasons to choose an American Rotary phase converter over other options. American Rotary phase converters offer line-to-line voltages that are balanced within 5% and gives full power. This means your equipment runs better and lasts longer than on a static converter which only allows you to get 2/3rds of the power. The second reason to choose a rotary converter from American Rotary is that American Rotary offers a Lifetime warranty on its phase converters compared to a solid state digital converter’s 1 year warranty and static’s 90 day – 1 year warranty.

Can I run multiple loads with one phase converter?

Yes, as long as the total amp draw of the equipment, that will be running at the same time, is less than the output rating of the phase converter.

What is the difference between delta configured and wye configured power?

Delta-configured power has four wires: three hot wires and a ground. Wye-configured power uses five wires: three hot wires, one ground, and one neutral. Phase converters will provide delta-configured power. If your intended load requires wye-configured power, you will need a delta-to-wye transformer on the output of the phase converter to power the load.

Can I use a rotary phase converter to run equipment that requires a neutral?

Yes, but the output of the phase converters is delta-configured, meaning it has no neutral line. You will need a delta-to-wye isolation transformer on the output side of the phase converter to generate a neutral leg to power your equipment.

Can a phase converter change the voltage and frequency?

No, the output voltage will match the incoming voltage and can only be used at 60 Hz. But, you can use a transformer either before or after the phase converter to change voltage.

What size wires will I need for my phase converter?

American Rotary provides recommendations for input wiring in every product manual but, output wiring is based on the application. Consult a licensed electrician to ensure that your installation complies with national and local electrical code requirements.

How often do I need to change the capacitors in my phase converter?

Start and Run capacitors should be checked once a year as described in the product manual and should typically be replaced every three to five years.

Why is the output voltage on one leg of my 240 V phase converter 208 V to ground?

For a phase converter to generate three-phase power, the two incoming power lines are directly passed through to the output and the phase converter generates the third leg in a configuration known as “high-leg delta.” This will power most three-phase machines. Some machines however, require wye-configured power, which includes a neutral. If your machine requires wye-configured power, you will need to send the output of the phase converter through a delta-to-wye isolation transformer before going to your load.

Can I use a phase converter with a backup generator?

Yes, but this will also require setting up a delay timer for 20-30 seconds before power is transferred between utility power and the generator. Not using a delay timer can cause faults or cause damage to the converter that is not covered under warranty.

What size generator do I need?

The generator should be rated for at least 1.5-2 times the current rating of the phase converter to properly run a load.