Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
440
The sensitive earth fault detection used for rotor earth fault protection is then activated: O/C PROT. IEE = ON
in address 5101.
3.3.19 Checking the Rotor Earth Fault Protection during Operation
Rotor Earth Fault Protection (R, fn)
In Section 3.3, the rotor earth fault protection with earth resistance measurement was checked with the
machine at standstill. In order to exclude possible interference on the measurement circuit by the running gen-
erator, an additional test during operation is recommended.
Caution!
A rotor circuit not isolated from earth can result in a double earth fault in conjunction with an earth resistor in-
serted for checking purposes!
Nonobservance of the following procedures can result in material damage to the machine.
Make sure that the checked rotor circuit is completely isolated from the earth, to avoid that the earthing resistor
interposed for test purposes causes a double earth fault!
An earth fault is simulated via a resistor of approximately 90% of the trip resistance (RE<< TRIP, address
6003). In machines with rotating rectifier excitation, the resistor is placed between the measurement slip rings;
in machines with excitation via slip rings between one slip ring and earth.
Start up generator and excite it to rated voltage. If applicable, place measurement brushes into operation.
The rotor earth fault protection initiates pickup and, after T-TRIP-RE<< (10 s when delivered from factory), trip
indication (LED 2 and LED 1 as group indications for device pickup and device trip).
The earth resistance calculated by the device can be read out in the earth fault annunciations as „Re =“.
For generators with excitation via slip rings, the test can be repeated for the other slip ring.
Shut down generator. Remove earth fault resistor.
Activate the rotor earth fault protection: ROTOR E/F = ON in address 6001.
Rotor Earth Fault Protection (1 to 3 Hz)
In Section 3.3, the rotor earth fault protection was checked with the machine at standstill. In order to exclude
possible interference on the measurement circuit by the running generator, and specifically by the excitation
system, an additional test during operation is recommended.
Caution!
A rotor circuit not isolated from earth can result in a double earth fault in conjunction with an earth resistor in-
serted for checking purposes!
Nonobservance of the following procedures can result in material damage to the machine.
Make sure that the checked rotor circuit is completely isolated from the earth, to avoid that the earthing resistor
interposed for test purposes causes a double earth fault!
An earth fault is simulated via a resistor of approximately 90% of the trip resistance (6103, address RE<<
TRIP). In machines with rotating rectifier excitation, the resistor is placed between the measurement slip rings;
in machines with excitation via slip rings between one slip ring and earth.
Start up the generator and excite it to the rated voltage. If applicable place measurement brushes into opera-
tion.
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