Ground Current - GE F650 Instruction Manual

5.4 PROTECTION ELEMENTS
Table 5–51: QUANTITIES
POLARIZING MODE
VOLTAGE (Vo)
CURRENT (Ip)
Vo + Ip
Vo * Ip
The Ground Current menu incorporates the following overcurrent elements:
5
Ground time overcurrent (51G)
Ground instantaneous overcurrent (50G)
Ground directional element (67G)
5.4.5.1 GROUND TIME DELAYED OVERCURRENT ELEMENT (51G)
Ground TOC is a ground time delayed overcurrent protection element. The ground current is measured from the ground
input, terminals B9-B10, and it may be programmed as Fundamental phasor magnitude or RMS magnitude as required by
the application. The element trip can be time delayed using a selectable curve. It incorporates a reset time that is selectable
between instantaneous or linear.
Table 5–52: 51G ELEMENT SETTINGS
SETPOINT > PROTECTION ELEMENTS > GROUND CURRENT > GROUND TOC
GROUND TOC 1> GROUND TOC 2 > GROUND TOC 3
SETTING DESCRIPTION
Function permission
Input type
Pickup level
Curve shape
Time Dial
Reset type
Snapshot Event generation
The snapshot event setting enables or disables the snapshot event generation for this element.
5-62
DIRECTION
FORWARD
REVERSE
FORWARD
REVERSE
FORWARD
REVERSE
FORWARD
REVERSE
NAME DEFAULT VALUE
Function DISABLED
Input PHASOR(DFT)
Pickup Level 1.00
Curve IEEE Ext Inv
TD Multiplier 1.00
Reset INSTANTANEOUS N/A
Snapshot Events ENABLED
F650 Digital Bay Controller
COMPARED PHASORS
-Vo Io x 1 MTA
-Vo -Io x 1 MTA
Isg
Isg
- Vo
or
Isg
- Vo
or
Isg
- Vo
and
Isg
- Vo
and
Isg

5.4.5 GROUND CURRENT

STEP RANGE
N/A [DISABLED – ENABLED]
N/A [PHASOR – RMS]
0.01 A [0.05 : 160.00]
N/A [See list of curves]
0.01 s [0.00 : 900.00]
[INSTANTANEOUS – LINEAR]
N/A [DISABLED – ENABLED]
5 SETTINGS
Io
-Io
Io
Io
-Io
-Io
Io
Io
-Io
-Io
GEK-106310AB