3.4.4 3Ø, 4-Wire, Y-Connection
A three-phase, four-wire potential system can be provided using three output modules. The
vector relationships are referenced below. This Y-Connection has the advantage of being able to
supply a higher line-to-line voltage (1.73 x phase-to-neutral voltage). It is ideally suited for
simulating phase-to-ground faults. Voltage channel #1 is designated as V
a
with its phase
relationship set for 0
°
. Voltage channel #2 is then designated as V
b
and phase angle set for 120
°
.
Finally, voltage channel #3 is designated V
c
and phase angle set for 240
°
(for a 1-2-3 counter
clockwise rotation). V
a
, V
b
and V
c
are connected to the voltage potential binding posts on the
respective test sets. If a neutral is required, it is connected to a ground post on any voltage
output module to ground the load.
f
V = Desired Fault Voltage
a
f
V =
3
3
V 0
∠ °
b
f
V =
3
3
V 120
∠
°
c
f
V =
3
3
V 240
∠
°
Balanced 3
θ
, 4 Wire Y-Connection
39
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