GE Multilin F650 - Neutral Overvoltage Element High;Low (59 Nh;59 Nl); Phase Undervoltage Element (59 P)

5-84 F650 DIGITAL BAY CONTROLLER GEK-106310-AF
5.4 PROTECTION ELEMENTS CHAPTER 5: SETPOINTS
5.4.8.2 Phase undervoltage element (59P)
The Phase overvoltage element may be used as an instantaneous element with no intentional time delay or as a Definite
Time element. The input voltage is the phase-to-phase voltage, either measured directly from Delta-connected VTs or as
calculated from phase-to-ground (wye) connected VTs. The time delay can be set from instantaneous to 900 seconds. The
element reset can be delayed up to 900 seconds.
As in the case of the undervoltage element, this element generates independent pickup and trip signals for each phase.
The general signal is selectable by setting to be an OR or an AND of the phase signals.
Table 5-55: 59P element settings
Phase overvoltage element settings are:
Function Permission (Function): This setting indicates whether the phase overvoltage element is enabled or disabled.
Pickup Level: This is the voltage threshold over which the overvoltage element operates.
Trip time (Trip Delay): setting of the Protection element operation time.
Reset time (Reset Delay): Reset time of the Protection element.
Operation logic (Logic): This setting allows the element operation logic selection:
ANY PHASE The element operates under an overvoltage condition in any of the
three phases.
TWO PHASES The element operates under an overvoltage condition in at least two
phases.
ALL PHASES The element operates under an overvoltage condition in three
phases.
Snapshot Events: The snapshot event setting enables or disables the snapshot event generation for this
element.
5.4.8.3 Neutral overvoltage element high/low (59NH/59nl)
The Neutral Overvoltage element can be used to detect an asymmetrical system voltage condition due to a ground fault
or to the loss of one or two phases of the source.
The element responds to the system neutral voltage (3V0), calculated from the phase voltages or measured by the 4th
voltage transformer.
VT errors and normal voltage unbalance must be considered when setting this element.
The element time delay is selectable between 0 and 900 seconds and incorporates a reset with a selectable delay
between 0 and 900 seconds.
Notice that the neutral overvoltage element is not be available if a DELTA Connection is set in the Phase VT Connection
setting in General settings, and the fourth voltage transformer input is set to the busbar voltage for the synchronism
element (Vx in Auxiliary Voltage setting). This is because with this combination of settings it is not possible to calculate the
zero sequence component from the phase-to-phase voltage magnitudes.
SETPOINT > PROTECTION ELEMENT > SETTING GROUP X > Voltage Elements > Phase OV >
Phase OV 1> Phase OV 2 > Phase OV 3
setting Description Name Default Value Step Range
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Pickup Level Pickup Level 10 1 V [3 : 300]
Trip time Trip Delay 10.00 0.01 s [0.00 : 900.00]
Reset time Reset Delay 0.00 0.01 s [0.00 : 900.00]
Operation logic Logic ANY PHASE N/A [ANY PHASE – TWO PHASES – ALL PHASES]
Snapshot Event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]