3 Installation and Commissioning
344
7UM62 Manual
C53000-G1176-C149-3
Inventory of the
Technical Plant
Data
In order to check the protection configuration (masking and setting values) for
conformity with the plant requirements, it is necessary to make an inventory of the
technical data for the individual components of the primary plant. These components
include, among others, the generator or motor, the unit transformer (step-up
transformer) and the voltage and current transformers.
Where deviations from the planning data are found, the settings of the protection must
be modified accordingly.
Analog Inputs
The check of the current and voltage transformer circuits includes:
•
Inventory of the technical data
•
Visual inspection of the transformers, e.g. for damage, mounting position and
connections
•
Check of the transformer earthing, especially the earthing of the broken delta
winding in only one phase
•
Check of the cabling for conformity with the circuit diagram
Other checks that may be necessary for a specific job include:
•
Measuring the cable insulation
•
Measuring the transformation ratio (VT, CT) and the polarity
•
Measuring the burden
•
Checking the functions of test switches, if used for secondary testing.
•
Measuring transducers/ Measuring transducer connection
Binary Inputs and
Outputs
See also section 3.3.3.
G
Setting the binary inputs:
−
Check the jumper settings for the pick-up thresholds and modify, if necessary (see
section 3.1.3, Figures 3-7, 3-9 and 3-11, as well as Tables 3-3, 3-8 and 3-12)
−
Check the pick-up threshold – if possible – with a variable d.c. voltage source
G
Check the tripping circuits from the command relays and the tripping lines down to
the various components (circuit breakers, excitation circuit, stop valves, switchover
devices etc.)
G
Check the signal processing from the signal relays and the signal lines down to the
station control and protection system; to do so, energize the signal contacts of the
protective device and check the texts in the station control and protection system
G
Check the control circuits from the output relays and the control lines down to the
circuit breakers and disconnectors etc.
G
Check the binary input signals from the signal lines down to the protective device
by activating the external contacts
Auxiliary Contact of
VT Protective
Switches
Since it is very important for the undervoltage protection, the impedance protection
and the voltage-dependent definite time and inverse time overcurrent protection that
these functions are blocked automatically if the circuit breaker for the voltage
transformers has tripped, the blocking should be checked along with the voltage
circuits. Open for this the VT protective switches.
