The difference between Static and Rotary Phase Converter is that Rotary Phase Converter uses an idler motor to give you a continuous third phase, while Static Phase Converter just gives you a third phase for a startup boost. This means that if your 3-phase motor does not require full nameplate HP to operate on, you will be able to start your motor and use it at 2/3 of its horsepower.
If you are like many small shop owners, you probably don’t have a three-phase power supply readily available to use. So how does a brand new entrepreneur sets up and operates his 3-phase machines?
The solution is to use a phase converter to operate any 3-phase equipment from a single-phase power source. Phase converters can be easily installed by a licensed electrician and you have one less thing to worry about besides just running your production.
There are several phase converters available on the market right now and of course, many people trying to build their own variations of it. A Static phase converter is a device similar to a Rotary phase converter, only without an idler motor-generator.
A typical 3-phase induction motor has three windings and if you are trying to start it on a single-phase power current, it will lack the needed third phase to start itself. Static Phase Converter will create an additional phase in order for you to be able to start your motor, but then it drops out and your motor will continue to run on single-phase power (2 legs).
If you are just starting a project or you have this fancy hobby of creating wonderful things, you will have the following phase conversion systems to choose from:
Rotary Phase Converter (RPC). Idler motor generates the third leg and keeps on running to give you stable, but rough (if not balanced properly) three-phase power.
Static Phase Converter (SPC). It will start up your 3-phase motor and disconnect itself, leaving your machine with 2 legs of power to use.
Variable Frequency Drive (VFD). This device uses inverter technology to give you a varied frequency and could be used as a Phase Converter.
Electronic or Digital Phase Converter (DPC). It uses inverter technology to give you a third leg of power. These converters will provide the most balanced and regulated three-phase power, similar to the one that would come from utilities.