Type Of Transformer; Normal Operational Status; System Frequency - Siemens 7UT51 Instruction Manual

4
Transformer Differential Protection (87T and 87HS)
4.2.1

Type of Transformer

The relay uses different addresses and algorithms for
different types of protected objects. Address 7801
specifies what type of device or equipment is being
protected.
7801 PROT.OBJ
Type of device or equipment the relay is protecting.
Option Description
- -
2 WIND TRANSF two
- -
3 WIND TRANSF three
(7UT513 only)
MOTOR/GENERA- motor or generator (see Chapter 5)
TOR
two
2 ENDED TIE PT.
3 ENDEDTIE PT. three
-
1Ph. TRANSF single
Model 7UT513 is required if the protected transformer
has three windings, or if the application includes
measurement of a ground (or neutral) current. A
7UT513 can also be used to simultaneously protect
both a two-winding transformer and an additional
protected device.
4.2.2

Normal Operational Status

The differential functions (87 and 87HS) can be set
either to exist or not to exist in Address 7816.
Functions that are configured as NONEXISTENT (or
DISABLED) will not process annunciations and the
associated setting parameters will not be requested
during setting.
7816 87 STATUS
Choice of whether transformer differential
protection functions (87T and 87HS) exist.
Option
EXISTENT/
ENABLED
NONEXISTENT/
DISABLED
Once the 87T and 87HS functions exist, they can be
configured. Additionally, Address 7801 must be set as
a transformer. The function's operational status is set
in Address 1601. If the status is set to OFF, it will have
no effect on the result of the protective process;
therefore, no tripping is initiated. If BLOCK TRIPPING
is chosen, all functions are active except the trip
contacts and signal contacts; therefore, no tripping is
initiated
44
-
winding transformer (default)
-
winding transformer
-
branch bus (see Chapter 6)
-
branch bus (see Chapter 6)
-
phase transformer
Description
87T and 87HS functions
exist (default).
87T and 87HS functions do
not exist.
Note that the default setting is OFF. Without correct
parameter settings the relay may show unexpected
reactions which include false tripping.
1601 87 STATUS
Operational status of transformer differential protection
(87T and 87HS).
Option Description
OFF 87T and 87HS functions are inactive (default).
ON 87T and 87HS functions are active.
BLOCK 87T and 87HS functions are active except that
TRIPPING trip contacts and signal contacts will not
respond to 87T and 87HS events.
4.2.3

System Frequency

The rated nominal frequency of the protected
transformer is specified in Address 7899.
7899 FREQUENCY
Rated nominal frequency of the protected transformer.
Option
FREQ 50 Hz
FREQ 60 Hz
FREQ 16 2/3 Hz
Note: The choice of frequency affects the availability
the auxiliary protection functions. With rated
frequency 60Hz, the backup overcurrent time
protection or the restricted earth fault
protection/tank leakage protection (dependent
on the ordered model) can be used besides the
differential protection for transformers. If the
three-winding transformer protection is to be
used, only the backup overcurrent time
protection is available.
With rated frequency 50Hz, the backup overcurrent
time protection or the restricted earth fault protection/
tank leakage protection (dependent on the ordered
model) can be used in addition to differential
protection for transformers.
With rated frequency 16 2/3 Hz, no restriction
concerning the additional functions are present.
If, during configuration, more functions have been
selected than the device is able to process, the relays
will give a corresponding message after configuration
has been finished. These messages can be read out
in the operational annunciations.
7UT51 v3
Description
50 Hertz
60 Hertz (default)
-
16 2/3 Hertz
PRIM-2330C