BE1-951
Installation
12-29
Notes:
°
1.
The neutral ground (I
N
) operates on internally calculated residual (3Io) current (VXIN)
2.
VTP connections shown are for H1 case. See Figure 12-13 for S1 case connections
3.
3-wire connection shown. See Figure 12-20 for alternate VTP connections. A 4-wire
connection provides negative sequence and, if selected, zero sequence voltage polarizing
(V0IN or V0IG) for ground faults; 3-wire connection provides negative sequence voltage
polarizing.
4.
CT polarity connected to relay polarity, power flow from Bus to Line defined as power out
and = “+” watts; OC elements set for forward trip
5.
VX connected to external source of 3E
0
polarizing voltage.
Figure 12-32. Directional Ground OC Protection Using External Source of Zero Sequence Polarizing
Voltage (VX) Compared to Calculated Residual (3IO) (IN)