GE F650 Instruction Manual page 208

5 SETTINGS
b) CURRENT POLARIZATION OPERATION PRINCIPLES:
Operation Magnitude:
Polarization Magnitude:
To perform a directional comparison by current, the polarization magnitude used is the current measured at the relay Ip
input, terminals B11-B12, with input or "positive" in B11. This current is taken from the source (transformer or generator)
neutral grounding.
Direction is considered to be forward when the phase shift between both magnitudes is lower than 85º. If the angle is higher
than 85º, the fault is considered to be reverse.
The following table shows the element's output signals management (block and permission) depending on the polarization
type setting.
Table 5–50: OUTPUT SIGNALS MANAGEMENT ACCORDING TO THE POLARIZATION TYPE SETTING
POLARIZATION SETTING
Vo
Ip
Vo + Ip
Vo * Ip
Configuration of the required signals for blocking the neutral overcurrent elements from the signals provided by the neutral
directional elements is performed at Setpoint > Relay Configuration > Protection Elements using the inverted operation
signals to block the trip, as shown in the following example:
How to block neutral time overcurrent elements with neutral directional functions:
NEUTRAL TOC1 BLOCK = NOT (NEUTRAL DIR1 OP)
NEUTRAL TOC2 BLOCK = NOT (NEUTRAL DIR2 OP)
NEUTRAL TOC3 BLOCK = NOT (NEUTRAL DIR3 OP)
To block neutral instantaneous elements:
NEUTRAL IOC1 BLOCK = NOT (NEUTRAL DIR1 OP)
NEUTRAL IOC2 BLOCK = NOT (NEUTRAL DIR2 OP)
NEUTRAL IOC3 BLOCK = NOT (NEUTRAL DIR3 OP)
GEK-106310AB
In = calculated from phase currents.
Ip, measured at input terminals B11-B12.
NEUTRAL DIR BLOCK SIGNAL
Vo < POL V THRESHOLD setting
Ip < 5 mA
Vo < POL V THRESHOLD
Ip < 5 mA
Vo < POL V THRESHOLD
Ip < 5 mA
F650 Digital Bay Controller
5.4 PROTECTION ELEMENTS
NEUTRAL DIR OP SIGNAL
Permission Vo
Permission Ip
Permission Vo
Permission Ip
Permission Vo
Permission Ip
5
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