S&C IntelliRupter PulseCloser Manual page 23

Figure 10. Phase-A direction example for a 1-2-3 rotation.
Table 1. System Grounding Method for Terminal-Y Fault
Directional Operating
Measurement Current
Phase-A IA
Phase-B IB
Phase-C IC
Ground 3I0
Zero Sequence
(SEF filtered 3I0
3V0>10%)
Referring to Table 1 and Figure 10 and using the Terminal-Y Phase-A directional
measurement as an example, V
The Terminal-Y Phase-A MTA is -45° for a 1-2-3 (A-B-C) rotation.
Therefore,
Substituting -45° from Table 1 for ∠MTA, maximum torque is achieved when
or the Terminal-Y Phase-A directional MTA occurs when IA leads VBC by 45° for a
1-2-3 rotation.
Referring to Table 1 and Figure 11 on page 24, if the corresponding operating current
leads or lags its reference voltage by ±90° from the respective maximum torque angle
(MTA), the fault is determined to be on Terminal-Y. Otherwise, the fault is determined
to be on Terminal-X, or is unknown.
Reference
Voltage
VB - VC
VC - VA
VA - VB
-135º
3V0 +135º
+135º
+90º
3V0 0º
-135º
is the reference voltage and I
BC
∠MTA = ∠V - ∠I
, and
BC A
∠I = ∠V - ∠MTA
A BC
∠I = ∠(V
+ 45°),
A BC
S&C Instruction Sheet 766-530
General Setup
Terminal Y
Max Torque Angle
-45º (1-2-3 rotation)
+135º (1-3-2 rotation)
Ungrounded
Uni-Grounded
Resonant
All others
Ungrounded
Uni-Grounded
Resonant
All others
is the operating current.
A
23