There are several ways to convert single-phase power to three-phase power. A phase converter is a device used to run three-phase equipment from a single-phase power supply.

There are three main types of phase converters:

• There are Rotary Phase Converters, Static Phase Converters, Digital (VFD) Phase Converters. Rotary Phase Converter are the most widely used phase converters, they are the most dependable power conversion, rotary phase converters can vary from manufactures, if you are looking for the best rotary phase converters, use Phoenix Phase Converter or CNC rated Phase Converter. Static Phase Converters or also know as the latest familiar DPS Converters are basically just a start capacitor and a relay, it doesn't produce three phase power, it mearly just uses a start capacitor to get your load motor to start and then it releases the start cap from the circuit, Then you are single phasing a three phase motor, this is less efficient too. A digital phase converter will converter single phase to three phase at a balanced voltage athough they are more costly and less durable, also the power out of a digital phase converter requires an electronic filter to remove the DC power leaking into the AC output lines, this is the reason they have inverter rated motors.
• Rotary Phase Converters: Most widely used and dependable, these converters vary by manufacturer. Phoenix Phase Converters and CNC-rated phase converters are highly recommended.

If you are a hobbyist and have a small three phase saw, milling machine, drill press, you may use a static phase converter although you will lose a third of the rated horsepower on the motor, which will cause loss of efficiency as well, free spinning equipment should last many years depending how the equipment is used. A rotary phase converter is defiantly required for harder loads and loads that require balanced three phase voltage, such as lathes, air compressors, vacuums, CNC machines, wide belt sanders (timer-savers) ect.. Digital Rotary Phase Converters have the benefits of clean power with digitally controlled relays and contactors, Digital Phase Converters (VFD's) are great source of power where a rotary phase converter can not be used, for example, at a dentist or doctors office for x-ray machine, a home elevator that does not get used much or small or super quiet environment.

A Static Phase Converter or DPS Phase Shift, can run multiple machines, although they will be rated to start a machine for the rated HP you have on the static phase converter. for an example you can have a 3 to 5 HP static phase converter, You won't be able to start over or under that value which is also based on the load type, although once you start the load it is intended for you can start other equipment from the same size motor you are running and smaller, because your load motor will act like a rotary phase converter but missing the run caps to balance out the voltages, this is not the ideal way because not ony you are using the load motor for your load but you are using the windings as a load for your other equipment when it is just intended for the actual machine. A rotary phase converter is the ideal phase converter to run multiple equipment as the same time, even starting the equipment at the same second, your load is pulled off the idler motor that has no other loads including anything mounted to the shaft of the idler motor, which this way your motors on your equipment use less amps, a rotary phase converter are also use to run resistive types of loads, such as heating elements, battery chargers, plasma cutter, welders, as well as running resistive loads with inductive loads. A Digital Phase Converter can run multiple equipment but not recommended to run with a VFD, transformers, and a mix of resistive loads and inductive loads together.

Light-duty can be describe in two ways, either by operating small easy to start equipment and also by the construction of how the phase converter is built, light duty phase converter are made from a rolled steel sheet wrapped around the stator and windings and have open vents all around to allow the air to pass over the winding for cooling, this will allow for dust and moister, oils and contaminates to enter the frame of the idler motor as well, eventually the motor can over heat and fail. The phase converter electrical enclosure could be mounted on the motor or wall on these lighter duty phase converter, also they are built by sheet metal and require many screw to hold the unit together in order for the sheet metal not to bend with pressure. While heavy duty phase converters like Phoenix Phase Converters are built with a totally enclosed fan cooled generator (TEFC) vs the open drip proof (ODP) light duty idler motors. Phoenix Phase Converter offer this as a standard they are well know for durability and clean balance voltage, their electrical panel uses a NEMA 4 design that are made from heavy gauge steel with hinged cover that closes on a thick rubber seal, this setup can be used indoor or outdoor and any environment.

While some converter are easy to install and the instructions are straight forward, it is always recommended to have an industrial licensed electrician to assure everything is set up correctly and meets local and state codes.

With a rotary phase converter or digital phase converter you don't lose any of the power to your load motors, with a static phase converter or DPS you will lose 1/3 oh the rated horsepower to your tool motor. Keep in mind your single phase line will draw 1.76 times more then your three phase amps.

Yes as long as they are rated for outdoor use-- NEMA 3 or NEMA 4 electrical panel enclosure and also a totally enclosed fan cooled (TEFC) idler generator motor.

Yes, Only CNC Grade type phase converters such as Phoenix Phase Converters are well know for CNC type equipment, the voltage output from the phase converter must be balanced voltage design for CNC equipment, it is also recommended to have the phase converters with digital controls.

Yes, a welder is a resistive type of load, you tipically what 1 HP per every amp of load to maintain a balanced voltage, a unbalanced load can damage rectifiers.

Yes a voltage balanced rotary phase converter or a digital phase converter can run a VFD drive, a rotary phase converter is recommended for VFD's

Rotary Phase Converter require very little maintenance especially with the heavy duty phase converters (TEFC) they are sealed from the environment, with the light duty (ODP) you will need to blow out or clean the motor/idler motor from time to time and may replace the bearings more often. Static Phase Converter also DPS (digital phase shifter) and Digital Phase Converters (VFDs) require no maintenance.

If it is a rotary phase converter it can be electrical noise either from a fused contactor, a blown capacitor, the motor wired incorrectly, or the phase converter is not up to speed. Contact the manufacture to help you fix this issue, a mechanical noise from the idler motor usually comes from a light duty phase converter (ODP) make sure the rotor and stator is clear from any obstructions, in a heavy duty phase converter (TEFC) check the fan housing for a loose fan, or the rubber seal press up against the house on the shaft might be dry of it is making a high pitch noise.

First determine if you have the right phase converter for your application, either if it is a static phase converter or digital Phase Shifter (DPS) rotary phase converter or digital phase converter, then determine you have the right size phase converter, next determine if you have enough power, if all three lines are dropping in voltage it is most likely your power feeding the phase converter, the wire can be too small, to long or your service can be weak. Also check the voltage produce by the phase converter to make sure you don't have one of the phase much lower then the other.