Siemens SIPROTEC 7UM62 User Manual

Functions
2.5 Power System Data 1
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
57
For the overcurrent protection functions (Sections 2.8, 2.9, and 2.10) and for the breaker failure protection,
sides 1 and 2 can be allocated freely. If the differential protection is set to 120 3 phase transf., the following
normalizing factors apply for the primary side protection settings in DIGSI.
Setting parameters:
S
N, Transf
249 SN TRANSFORMER
U
N, S1
241 UN-PRI SIDE 1
S
N, Generator
252 SN GEN/MOTOR
U
N, Generator
251 UN GEN/MOTOR
These normalizing factors apply for transformer protection and overall protection (see Section2.4.2, Figure 2-
5 „Block Differential Protection“ and Figure 2-6 „Transformer Differential Protection“).
Protected Object: Generator/Motor
Regardless of the configuration and intended use of the differential protection, the generator/motor ratings must
be specified. Parameter 251 UN GEN/MOTOR specifies the primary rated voltage of the protected generator or
motor. At parameter 252 SN GEN/MOTOR the rated apparent power is entered. From these values the nominal
generator/motor current for plant side 2 is calculated:
Setting parameters:
S
N, Generator
252 SN GEN/MOTOR
U
N, Generator
251 UN GEN/MOTOR
The above formula is also used by the DIGSI program to establish the normalizing factors for the primary side
protection settings of the overcurrent protection functions (Sections 2.8, 2.9, and 2.10) and of the breaker
failure protection, where the sides 1 and 2 can be freely allocated. Normalization is active if the differential pro-
tection in the scope of functions is set to 120 Disabled or Generator/Motor. It applies for both side 1 and
side 2.
At addresses 242 STARPNT SIDE 1 and 244 STARPNT SIDE 2 you specify the starpoints. For generator
protection applications, set Isolated. This is even valid if a loading resistor is connected to the generator star-
point. An exception from this are low-voltage machines with solid starpoint earthing.
Rated System Frequency
The nominal frequency of the system is set in Address 270 Rated Frequency. The factory setting of the
model variant must only be changed if the device is to be used for a purpose other than intended when ordering.

Siemens SIPROTEC 7UM62 Specifications

General

Brand	Siemens
Model	SIPROTEC 7UM62
Category	Protection Device
Language	English