Welcome to Phase Perfect’s general questions and answers section, where
we hope you find answers to your questions about digital phase converters.
Please let us know if you encounter any problems or have suggestions for this FAQ on phase converters. To send a comment or suggestion, visit our Contact Us page.
How are Phase Perfect electrical phase converters different from other phase converters?
Phase Perfect digital phase converters are a revolutionary new concept in digital phase converters. Utilizing the latest developments in solid state electronics and computer control, it balances three-phase voltages to within 1% under all load conditions with true unity power factor and virtually no harmonic distortion. No other phase converter can equal this performance.
Why is voltage balance important in electrical phase converters?
When the voltage between the three phases are not equal, the current increases dramatically in the motor windings, creating heat. If allowed to continue, this heat will damage the motor. It is possible, to a limited extent, to operate a motor when the voltage between the phases is not balanced. To do this, the load must be reduced. As a rule of thumb, if the voltage is out of balance by just 5%, the motor must be derated to 75% of its rated capacity. Contrary to digital
converters, rotary and static converters are commonly 25-30% out of balance!
How is the power quality from Phase Perfect better than utility supplied power?
Most electric utilities provide three-phase power in a "nominal" voltage specified within +/- 10%. Other users on the same distribution lines can affect the voltage supplied to you on each of the three legs of three-phase power by as much as 10% before the utility takes corrective action. Phase Perfect always balances three-phase voltages to within 1%. It also provides protection for three-phase equipment against over voltage, under voltage and single phasing. Protecting your equipment from these damaging situations on utility three-phase requires the purchase of special equipment.
Are there any special sizing considerations for Phase Perfect based on the application for which it will be used?
Selecting a Phase Perfect digital phase converter is simple. Just match the name plate specifications of your application with a Phase Perfect model rated at least as large as the load you will operate. Unlike rotary and static converters, there is no need to oversize Phase Perfect for hard starting motors or voltage sensitive loads. Phase Perfect electrical phase converters can safely and efficiently operate virtually any three-phase load within its rated capacity!
What does "Motor Starter Capability" mean?
AC electric motors require equipment in a "starter panel" to be operated. This equipment generally must include a fusible disconnect, a contactor, and a motor overload protection unit. Phase Perfect digital phase converters have these components integrated into its design, and can be configured to function as a starter panel. Most single motor applications can be operated by simply wiring the motor to terminals inside Phase Perfect.* This feature can save hundreds of dollars compared to other converters or to utility three-phase.
Is additional equipment such as a
motor starter panel needed to install Phase Perfect electrical phase converters?
No. Phase Perfect comes complete and ready to use. Simply connect wires from your service panel to terminals inside Phase Perfect digital phase converter, and it is ready to supply your three-phase power needs.* Rotary converters usually require a panel to start the converter
motor and another panel to start the motor load!
How does a Phase Perfect digital phase converter protect the equipment it operates?
Sophisticated software in a digital signal processor (DSP) controls the phase conversion process and continuously monitors load conditions. It balances output voltages, and shuts down in situations that can damage the electrical phase converter or the load being operated. Rotary and static converters are electromechanical devices that have changed little since they were invented in the middle of the past century. They cannot respond to changes in the load and input voltages or make decisions to protect your equipment.
What is unity power factor and why does it matter?
When AC induction motors draw current from the power lines, the sine wave pattern of the current lags the voltage. This relationship between current and voltage can be calculated through trigonometry and expressed as a number called power factor. When the power factor is one (1.00), this means that the voltage and current pattern are in sync. A poor power factor (e.g. .65) requires the utility to generate more current than the load actually needs to do its work. The utility may assess the customer a charge for this poor power factor or require the installation of power factor correction equipment. Phase Perfect always operates at near unity power factor (.99, slightly leading), so that the utility does not see the poor power factor of induction motors being operated by Phase Perfect. Rotary phase converters can actually make the power factor worse, resulting in inefficient operation and extra charges.
How efficient are Phase Perfect digital phase converters?
Phase Perfect digital phase converter operates three-phase equipment at 95-98% efficiency, while its power factor correction results in better overall efficiency than most other three-phase solutions.
If I can buy rotary or static phase converters for less, why should I buy a Phase Perfect Power digital phase converter?
Phase Perfect digital phase converters have several distinct advantages over static and rotary phase converters that provide value to the end-user.
Phase Perfect typically operates at 97% efficiency, compared to typical 80-90% for rotary converters, resulting in significantly lower life-time operating cost.
Phase Perfect is quick and easy to install, reducing installation cost.
Most importantly, Phase Perfect always delivers clean, balanced power. Unbalanced voltage from other phase converters has the potential to damage valuable three-phase electrical equipment.