Waveform Examples for Phase Loss on Delta Input

Phase Loss on the DELTA primary

The loss of a phase on the input side of the TEAL power subsystem (almost always a 4 wire DELTA input) will create a unique waveform signature on the output side (almost always a 5 wire WYE with a neutral connection).

This waveform will typically be captured by the TEALwatch as a Voltage Sag, although it may be caught as a Frequency Deviation depending on what part of the waveform distorts initially.

This unique waveform signature is shown below.

Signature waveform example of the loss of an input Delta Phase,
captured as a Voltage Sag. In the event of the loss of a phase to the input
of the TEAL power subsystem (losing 1 phase of the 3 phase delta), you
will likely see a waveform captured that will resemble this waveform. Effectively,
1 corner of the delta has collapsed, so 2 phases on the output (WYE) side
(phases B & C above) drop to nearly 50% of nomimal voltage amplitude, and
their frequency becomes nearly in sync, and 180 degrees out of phase with
the remaining "good" phase (phase A shown above).

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.