CHAPTER 6: SETPOINTS
S2 SYSTEM SETUP
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
6–27
Figure 6-12: Broken delta connection
AUX VT SECONDARY
Range: 50 V to 240 V
Default: 110 V
This setting defines the voltage across the VT secondary winding when nominal voltage
is applied to the primary. On a source of 13.8kV line-line voltage, with a VT ratio of
14400:120 V delta connection, the voltage to be entered is “115 V”. For a Wye
connection, the voltage to be entered is 115/
√
3 = 66 V.
AUX VT RATIO
Range: 1.0:1 to 5000.0:1
Default: 1.0:1
This setting defines the VT primary to secondary turns ratio. For a 14400: 120 VT, the
entry would be “120.0:1” (14400/120 = 120).
NOTE
NOTE:
The 350 relay can be applied to both metering and protection feeders with up to 550 kV
phase-to-phase voltage. Please ensure that the selected VT ratio and VT secondary do not
result in a primary voltage exceeding 550 kV.
D12
V
X
E12
V
X
D11
V
X
E11
V
X
D10
V
X
E10
V
X
D9
V
X
E9
V
X
A
B
C
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