Calculated ground fault
The current produced by the generator is monitored depending on how parameter
"Generator current measuring" (parameter
) is configured. The measured three
conductor currents IGen-L1, IGen-L2 and IGen-L3 are vectorially totaled (IS = IGen-L1 +
IGen-L2 + IGen-L3) and compared with the configured fault limit (the calculated actual
value is indicated in the display). If the measured value exceeds the fault threshold limit,
a ground fault is present, and an alarm is issued.
Fig. 188:
Generator ground fault - schematic
If this protective function is triggered, the display indicates "Ground fault 1" or "Ground
fault 2" and the logical command variable "06.19" or "06.20" will be enabled.
The ground fault protection zone is determined by the location where the generator
current transformer are physically installed.
⚙
Test
1. ▷
Short-circuit one of the three generator current transformers while the generator is at
full load.
▶
The measured current should read 100% of rated on the two phases that do not have
their current transformers short-circuited.
The ground current calculation does not take current on the neutral conductor into
consideration. In order for the controller to be able to perform calculated ground fault
current protection accurately, the neutral conductor must not conduct current.
The fault threshold value is configured as a percentage. This percentage threshold refers
to the generator rated current (parameter
asymmetries, the minimum value for this parameter should be 10% or greater.
460
easYgen-3000XT Series
B37574
4 Configuration
4.5.1.6.2.1 Generator Ground Fault (Level 1 & 2)
Released