Signals; Settings - ABB RELION 620 Series Technical Manual

1MAC504801-IB E
4.1.7.6
4.1.7.7
Table 176: 46 Group settings
Parameter Values (Range)
Pickup value 0.01...5.00
Pickup value mult 0.8...10.0
Time multiplier 0.05...15.00
Table continues on next page
620 series ANSI
Technical Manual
also provides a back-up protection functionality for the feeder ground-fault protection in
solid and low resistance grounded networks.
The negative sequence overcurrent protection provides the back-up ground-fault
protection on the high voltage side of a delta-wye connected power transformer for ground
faults taking place on the wye-connected low voltage side. If a ground fault occurs on the
wye-connected side of the power transformer, negative sequence current quantities
appear on the delta-connected side of the power transformer.
Probably the most common application for the negative sequence overcurrent protection
is rotating machines, where negative sequence current quantities indicate unbalanced
loading conditions (unsymmetrical voltages). Unbalanced loading normally causes
extensive heating of the machine and can result in severe damage even over a relatively
short time period.
Multiple time curves and time multiplier settings are also available for coordinating with
other devices in the system.

Signals

Table 174: 46 Input signals
Name Type
I SIGNAL
2
BLOCK BOOLEAN
ENA_MULT BOOLEAN
Table 175: 46 Output signals
Name Type
TRIP BOOLEAN
PICKUP BOOLEAN

Settings

Unit Step
xIn 0.01
0.1
0.01
Default Description
0 Negative phase sequence current
0=False Block signal for activating the blocking mode
0=False Enable signal for current multiplier
Description
Trip
Pickup
Default Description
0.30 Pickup value
1.0 Multiplier for scaling the pickup value
1.00 Time multiplier in IEC/ANSI IDMT curves
Section 4
Protection functions
237