GE Multilin F650 - Ground Directional Element (67 G); Ground Instantaneous Overcurrent Element (50 G)

5-74 F650 DIGITAL BAY CONTROLLER GEK-106310-AF
5.4 PROTECTION ELEMENTS CHAPTER 5: SETPOINTS
5.4.5.2 Ground instantaneous overcurrent element (50G)
Ground IOC is a ground instantaneous overcurrent protection element, with a setting range from 0.05 A to 160 A, which
can also be time delayed. The delay is selectable between 0.00 and 900 seconds. The ground current input quantity is
measured from the ground input, and it may be programmed as Fundamental phasor magnitude or RMS magnitude as
required by the application. The element incorporates a reset time selectable between 0 and 900 seconds, and a block
input that resets the pickup and trip signals to 0. The element outputs are the general pickup and trip signals of the
element.
Table 5-43: 50G element settingS
The snapshot event setting enables or disables the snapshot event generation for this element.
5.4.5.3 Ground directional element (67G)
Ground directional is a directional protection element, used for monitoring the ground overcurrent elements. The
operation magnitude is the ground current measured directly from the corresponding input (B9-B10), while the
polarization magnitude is the neutral voltage (V
n
). The neutral voltage is calculated from the three phase voltages or
measured from the dedicated voltage input (A11-A12).
In case of using the voltage measured from the dedicated voltage input terminals, the Auxiliary Voltage setting in General
settings must be VN.
If the F650 is set to have synchronism check protection, then this input is adjusted as busbar voltage and it will not be
the 3V0 voltage (AUXILIARY VOLTAGE setting as VX)
If the F650 does not have a synchronism check element, then this input can be set as I
n
neutral voltage, and it can be
used as polarization magnitude for the 67G element (AUXILIARY VOLTAGE setting as VN).
As in the case of a phase directional element, this element incorporates a voltage loss logic that allows blocking or
permitting the trip by means of a setting.
Table 5-44: 67G element settings
SETPOINT > PROTECTION ELEMENT > SETTING GROUP X > Ground Current > Ground IOC
Ground IOC 1> Ground IOC 2 > Ground IOC 3
setting Description Name Default Value Step Range
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Input type Input PHASOR(DFT) N/A [PHASOR – RMS]
Pickup level Pickup Level 30.00 0.01 A [0.05 : 160.00]
Trip time Trip Delay 0.00 0.01 s [0.00 : 900.00]
Reset time Reset Delay 0.00 0.01 s [0.00 : 900.00]
Snapshot event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]
SETPOINT > PROTECTION ELEMENT > SETTING GROUP X > Ground Current > Ground Directional >
Ground Directional 1> Ground Directional 2 > Ground Directional 3
setting Description Name Default Value Step Range
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Maximum Torque Angle MTA -45 1 Deg [-90 : +90]
Operation Direction Direction FORWARD N/A [FORWARD – REVERSE]
Polarization type Polarization VO N/A [V
0
– I
P
– V
0
+I
P
– V
0
*I
P
]
Block logic type Block Logic PERMISSION N/A [BLOCK – PERMISSION]
Polarization voltage threshold Pol V Threshold 10 1 V [0 : 300]
Snapshot event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]