Waveform Examples for Phase Balance Events

Phase Balance Event

A Phase Balance Event will be triggered (and a waveform consequently captured) when the of the phase balance of the RMS value of the voltage waveforms, normally 120 degrees, exceeds the triggering threshold. Most systems will operate fine with a few degrees of phase balance difference (115 to 125 degrees, for example), but a larger phase imbalance could cause clocking or triggering problems in electronic systems that rely on voltage waveform zero-crossing points or phase relationships.

This type of waveform is more obvious if you carefuly examine the zero-crossing points of the voltage waveforms. The zero-crossing points would normally be evenly spaced, but with a phase balance issue, they will begin to crowd closer together.

An example of a Phase Balance waveform signature is shown below.

Example of a Phase Balance Event. This event trigger occurs when the nominal
balance between the 3 AC phases becomes unbalanced. The typical range for
the Phase Balance trigger is 7 degrees from nominal, typically 120 degrees for
a normal 3-phase system. Note that the zero-crossing point is not consistent.

How Do I Adjust The Trigger Thresholds?

To adjust the set-points of the event triggers, please refer to the Users Manual, section 3.6.

How Do I Eliminate These Kinds of Events?

To reduce or eliminate these kinds of power events, you may need to increase the level of your power conditioning to a Voltage Regulator or a UPS. For more information, visit our Additional Power Conditioning web-pages.

For a sampling of various Case Studies that describe various power quality issues and their causes, please visit our Case Studies webpage.

For more information, please contact the TEAL Marketing Department.