ABB RELION REF615R, Техническое руководство

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Therefore, this function is often used as a back-up protection or as a release signal for the
feeder ground-fault protection.
The protection can also be used for the ground-fault protection of generators and motors
and for the unbalance protection of capacitor banks.
The ground voltage can be calculated internally based on the measurement of the three-
phase voltage. This voltage can also be measured by a single-phase voltage transformer,
located between a transformer star point and ground, or by using an open-delta connection
of three single-phase voltage transformers.
The function is typically designated as 59G when broken delta voltage from the VT is
measured as 3V0 value on Sensor 9 or 10 input. Alternatively, it is designated as 59N
when a calculated 3V0 value is used as input to the function based on calculated 3V0 from
the three phase-ground voltage inputs.
When the input VT is V (open delta) connected, zero sequence voltage
cannot be calculated and hence 59N function cannot be employed.
4.2.3.6 Signals
Table 187: 59G/N Input signals
Name Type Default Description
VG SIGNAL 0 Ground voltage
BLOCK BOOLEAN 0=False Block signal for activating the blocking mode
Table 188: 59G/N Output signals
Name Type Description
TRIP BOOLEAN Trip
PICKUP BOOLEAN Pickup
4.2.3.7 Settings
Table 189: 59G/N Group settings
Parameter Values (Range) Unit Step Default Description
Pickup value 0.010...1.000 xUn 0.001 0.030 Pickup value
Trip delay time 40...300000 ms 1 40 Trip delay time
Section 4
1MRS240050-IB C
Protection functions
240 REF615R
Technical Manual