Mounting and Commissioning
3.3 Commissioning
SIPROTEC, 7UM62, Manual
C53000-G1176-C149-7, Release date 03.2010
423
The theoretical angles depend on the protected object and – in the case of transformers – on the vector group.
They are listed in Table 3-29 for clockwise phase rotation.
The polarity of the CT connections and the parameterized polarity are taken into consideration for the angles
displayed. Thus, if all three angles differ by 180° from the theoretical value, the polarity of one complete trans-
former set is wrong.
This can be corrected by checking and changing the corresponding system parameters:
Address 201 STRPNT->OBJ S1 for primary winding,
Address 210 STRPNT->OBJ S2 for secondary winding
Table 3-29 Displayed phase angle dependent on the protected object (three phase)
1)
Angles are valid if the high voltage side is defined as side 1, Otherwise, the angles of vector group 12–x (x
= set vector group) apply.
Differential and Restraint Currents
Before the tests with symmetrical currents are terminated, the differential and restraint currents are examined.
Even though the symmetrical tests which have been carried out so far should have revealed more or less all
possible connection errors, matching errors or wrong vector group allocations cannot be ruled out.
Under the operational mesured values you can read out the calculated values. Note that differential and re-
straint values are referred to the rated current of the protected object. This must be considered when they are
compared with the test currents.
If considerable differential currents occur, recheck the following parameters:
For transformer protection:
Addresses 241, 249 and 202 (matching winding 1), 243, 249 and 211 (matching and vector group winding 2);
For generator or motor protection:
Addresses 251 and 252 (matching of machine ratings);
The symmetrical current tests are now completed. Disconnect the protected object (shut down generator) and
earth it, remove the test setup.
Switch the differential protection to active (address 2001: DIFF. PROT. = ON) and it works immediately as a
short-circuit protection for all subsequent tests.
Protected object
→
Generator/Motor Transformer with Vector Group Numeral
1)
→ Power Angle 01234567891011
ϕL1L2 180° 180° 150° 120° 90° 60° 30° 0° 330° 300° 270° 240° 210°
ϕL2L2 60° 60° 30° 0° 330° 300° 270° 240° 210° 180° 150° 120° 90°
ϕL3L2 300° 300° 270° 240° 210° 180° 150° 120° 90° 60° 30° 0° 330°
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