GE 850 User Manual

5–66 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
SYSTEM CHAPTER 5: DEVICE, SYSTEM, INPUT AND OUTPUT SETPOINTS
PHASE CT PRIMARY
Range: 1 A to 12000 A
Default: 500 A
Enter the primary rating of the three-phase feeder CTs wired to the relay phase CT
terminals. With the phase CTs connected in wye (star), the calculated phasor sum of the
three phase currents (Ia + Ib + Ic = Neutral Current = 3I0) is used as the input for the
neutral.
GROUND CT PRIMARY
Range: 1 A to 12000 A
Default: 500 A
Enter the primary rating of the ground CT wired to the relay ground CT terminals. When
the ground input is used for measuring the residual 3I0 current, the primary current
must be the same as the one selected for the phase CTs.
SENSITIVE GROUND CT PRIMARY (displayed only if the Sensitive ground input is
installed)
Range: 1 A to 12000 A
Default: 500 A
Enter the primary rating of the sensitive ground CT wired to the relay sensitive ground CT
terminals.
FAST PATH:
The cut-off for current measurements is 0.02 x CT. This is the minimum value above which
metering functions.
NOTE
NOTE:
The Setpoints > System > Current Sensing > CT Bank 3 -K2 option is available in 850 with
order code option R1/R5 for Phase Current Slot K.
NOTE
NOTE:
The Setpoints > System > Current Sensing > CT Bank 4-JK option is available in 850 with
order code option P1/P5 for Ground Currents.
Voltage Sensing
Traditional VT The Voltage Sensing menu provides the setup for all VTs (PTs) connected to the relay
voltage terminals.
The 850-E can be connected to 4 VTs, i.e. three-phase VTs from either a Wye (Star) or a
Delta connection, and one auxiliary VT (Slot J).
The 850-D can be connected to 2 three-phase VT banks from either a Wye (Star) or a Delta
connection, and one auxiliary VT (Slots J and K).
The 850-P can be connected to 6 LEA inputs or one three-phase VT from either a Wye (Star)
or a Delta connection, and one auxiliary VT (Slots J and K).
Path: Setpoints > System > Voltage Sensing > Ph VT Bnk1-J2
PHASE VT BANK NAME
Range: Any combination of 13 alphanumeric characters
Default: Ph VT Bnk 1-J2
Enter the name of the phase voltage from bank J2.
PHASE VT CONNECTION
Range: Wye, Delta
Default: Wye
Select the type of phase VT connection to match the VTs (PTs) connected to the relay.

GE 850 Specifications

General

Brand	GE
Model	850
Category	Protection Device
Language	English