Adapting Single-Phase Products Into Three-Phase Power Systems

Executive Summary

In many industrial facilities or environments, only three-phase power is available. Many lower power products operate off a single-phase input. This paper will demonstrate how to easily adapt a single-phase input product into a three-phase power system.


Depending on the facility and the installation, the three-phase power source may or may not include a neutral connection in addition to Phase A, Phase B and Phase C. 

Common voltages for three phase systems in North America include 4-wire Delta Systems with a phase-to-phase voltage of 208VAC/60Hz (phase-to-neutral voltage of 120V), or 480VAC/60Hz (phase-to-neutral voltage of 277V). In other parts of the world, typical power line voltages include 50Hz 5-wire WYE systems with a phase to phase voltage of 398VAC and a phase-to-neutral voltage of 230VAC, or a phase-to-phase voltage of 380V with a phase-to-neutral voltage of 220V.

Power conversion systems will typically be designed to draw power evenly from each phase so as not to overload wiring, distribution transformers or circuit breakers. Managing the loading of the three phases can be done by connecting apparatus separately to each phase in such a way that loading is balanced, or by using power converters that connect to all three phases simultaneously, automatically providing phase balance. 

Download App Note