The Bare Bones


For non-professionals, this part is for you. The phase is the physical distribution of a load. Single-phase power is distributed through an AC (alternating current) power circuit with two wires, a phase wire and a neutral wire. Three-phase power has three wires instead of two, and sometimes a fourth (neutral) wire. Three-phase power is more sophisticated and difficult to measure but it allows for the distribution of larger power loads and keeps the delivery of the power more consistent than single-phase.


Why does it Matter?


Most professional facilities run on three-phase, while homes use a single-phase supply most of the time. If you are working in or managing a facility with a lot of power, you’re going to be running three-phase power. The reliability, consistency of power delivery, and energy efficiency is worth the extra work and complexity of three-phase. They also transmit far more power than single-phase (up to 200% more) with only 50% more wire. That being said, the power quality issues with three-phase power are a lot more complicated than single-phase, so you’re going to need an analyzer that can measure the appropriate parameters and communicate that data to you clearly and quickly. Devices like the PS4550 and PS5000 power quality analyzers specialize in that and are a great choice for three-phase AC power analysis. They also monitor split-phase, single-phase, multiple single-phase, DC (direct current), and 2CT/2PT – 3CT/2PT – 3CT/3PT metering circuits.


What Three-Phase Parameters Should Get Measured?


There are a number of important power measurements that may be important to observe and gather data on. For voltage monitoring, sag/swell, unbalanced voltage, and transients are key issues to keep an eye out for. Similarly, current inrush (which can lead to voltage sags) should be captured and taken care of. Another big one is harmonics, which are easily measured with the right meter and can have implications in overheating and shortening the useful life of equipment. It is also beneficial to monitor power, in particular kW, kVA, kVAR, true power factor, displacement power factor, and peak demand. This can identify overconsumption of power and help save money spent on utilities.

PowerSight power quality analyzers measure all these elements and more with ease. Learn more on our products page or call our expert staff at (925)-944-1212.