12-26
Installation
BE1-951
Notes:
°
1.
The neutral ground (I
N
) operates on internally calculated residual (3Io) current
2.
VTP connections shown are for H1 case. See Figure 12-13 for S1 case connections
3.
4-wire connection shown as typical. See Figure 12-20 for alternate VTP connections. Note
that the 81 voltage inhibit function for 4-wire and single-phase L-N systems monitor A-N
voltage. 3-wire and single-phase L-L systems monitor A-B voltage.
4.
CT polarity connected to relay polarity, power flow from Transformer LS to Bus defined as
power out and = "+" watts
5.
VTX can be connected A-N, B-N, C-N or A-B, B-C, C-A. For the VTP connection shown,
VTX input can be A-N, B-N, or C-N. If a 3-wire VTP system is connected, use A-B, B-C, or
C-A for VTX input. Voltage magnitude between VTX and VTP must be matched external to
the relay.
6.
BE1-851 or 951 required on each circuit to implement high speed bus interlocking scheme
Figure 12-29. Dual Voltage Source UF Load Shed Using Optional VTX Input; OC Bus Protection
(Including High Speed Bus Interlocking)
