1MAC050144-MB C
Section 4
Protection functions
615 series ANSI
239
Technical Manual
blocked and the timers are reset. the "Block TRIP output" mode, the function operates
normally but the
TRIP
output is not activated.
4.2.3.5
Application
59G is designed to be used for ground-fault protection in isolated neutral, resistance
grounded or reactance grounded systems. In compensated networks, the pickup of the
function can be used to control the switching device of the neutral resistor. The function
can also be used for the back-up protection of feeders for busbar protection when a more
dedicated busbar protection would not be justified.
In compensated and isolated neutral systems, the system neutral voltage, that is, the ground
voltage, increases in case of any fault connected to ground. Depending on the type of the
fault and the fault resistance, the ground voltage reaches different values. The highest
ground voltage, equal to the phase-to-ground voltage, is achieved for a single-phase
ground fault. The ground voltage increases approximately the same amount in the whole
system and does not provide any guidance in finding the faulty component. 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.
4.2.3.6
Signals
Table 237: 59G Input signals
Table 238: 59G Output signals
Name
Type
Default
Description
VG
SIGNAL
0
Ground voltage
BLOCK
BOOLEAN
0=False
Block signal for activating the blocking mode
Name
Type
Description
TRIP
BOOLEAN
Trip
PICKUP
BOOLEAN
Pickup
Summary of Contents for 615 Series ANSI
Page 1: ...Relion Protection and Control 615 series ANSI Technical Manual ...
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Page 29: ...1MAC050144 MB C Section 615 series ANSI 22 Technical Manual ...
Page 389: ...Section 4 1MAC050144 MB C Protection functions 382 615 series ANSI Technical Manual ...
Page 485: ...Section 6 1MAC050144 MB C Supervision functions 478 615 series ANSI Technical Manual ...
Page 635: ...Section 10 1MAC050144 MB C Other functions 628 615 series ANSI Technical Manual ...
Page 711: ...Section 16 1MAC050144 MB C Glossary 704 615 series ANSI Technical Manual ...
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