EDM Avistar PhaseTrakker AP30 - Three-Phase Transformer Bank Readings

PhaseTrakker AP30 PhaseTrakker Utility
33
Three-Phase Transformer Banks
The secondary phases of a three-phase transformer bank (three standard single-
phase transformers connected to each other) will either match the primary phases
or be offset by 180° from the primary phases, depending on transformer polar-
ity and bank connections. 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 Bank Phase Readings
Primary
Secondary
In Phase
Secondary
Out of Phase
A
0°
A
0°
“No Match”
180°
B
-120° (240°)
B
-120° (240°)
“No Match”
60°
C
120°
C
120°
“No Match”
-60° (300°)
Phase angle readings will typically vary within 20° of values shown.
Phase angles and labels shown are the AP30 default values.