PhaseTrakker Utility
PhaseTrakker
AP30
34
Three-Phase Transformers, Delta-Wye
The three-phase transformers commonly used in distribution substations have a
delta arrangement for the primary connections and a wye arrangement for the
secondary connections. This results in a 30
°
phase shift between the primary and
secondary phases. The Field Unit can be set to compensate for this phase shift
(refer to the section Adjusting for Phase Shift).
Note: The table below assumes that all measurements (primary and
secondary) were taken with the same Field Unit Phase Shift setting.
Three-Phase Transformer (Delta-Wye) Readings
Primary
Secondary
Standard 30° Lag
Secondary
Non-Standard 30° Lead
A
0°
“No Match”
-30°
“No Match”
30°
B
-120° (240°)
“No Match”
-150° (210°)
“No Match”
-90° (270°)
C
120°
“No Match”
90°
“No Match”
150°
Phase angle readings will typically vary within 20° of values shown.
Phase angles and labels shown are the AP30 default values.
