Functions
2.32 Sensitive Earth Fault Protection B (ANSI 51GN)
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
234
2.32.2 Setting Notes
General
The sensitive earth fault protection IEE-B is only effective and available if configured to with IEE1 or with
IEE2 at address 154.
If the sensitive earth fault detection IEE-B is not required, Disabled is set.
Address 5401serves to switch the function ON or OFF or to block only the trip command (Block relay).
In addition, you can set Alarm Only, i.e. these stages operate and send alarms but do not generate any trip
command
Use as Shaft Current Protection
The correct setting of the shaft current protection is only possible during the primary check. A fault record is
started with the generator running and the harmonic content is determined using the SIGRA graphic software.
Depending on which harmonic content is present, the appropriate measuring method is set in address 5406
MEAS. METHOD. You can select either Fundamental, 3. Harmonic or 1. and 3. Harm.. Once the setting
is complete, the respective fault current is read out of the operational measured values with the generator
running under load and a setting value is determined on their basis with a safety factor of 1.5 to 2 (see also
primary check).
A preliminary setting should be so that it causes the protective function to pick up on fault currents between
0.5 A and 1 A. In case of 600 turns, this yields a pickup value of 1 mA (equivalent to 0.6 A primary).
To ensure that the function also trips in case of intermittent faults, the pickup behaviour has to be set in address
5407 T-HOLD IEE-B> (only possible via the DIGSI software). A value of 0.5 s is quite practicable. The trip
time delay is usually set to 3 s in address 5403 T IEE-B>.
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