Siemens SIPROTEC 4 7VK61 Manual page 206

Mounting and Commissioning
3.2 Checking Connections
•
Protective switches for the power supply and the measured voltages must be switched off.
•
Check the continuity of all current and voltage transformer connections against the system and connec-
tion diagrams:
– Are the current transformers earthed properly?
– Are the polarities of the current transformers the same?
– Is the phase relationship of the current transformers correct?
– Are the voltage transformers earthed properly?
– Are the polarities of the voltage transformers correct?
– Is the phase relationship of the voltage transformers correct?
–
Is the polarity for current input Ι
– Is the polarity for voltage input U
•
Check the functions of all test switches that are installed for the purposes of secondary testing and isola-
tion of the device. Of particular importance are test switches in current transformer circuits. Be sure these
switches short-circuit the current transformers when they are in the "test mode".
•
The short circuit links of the connectors for the current circuits have to be checked. This can be done
using secondary test equipment or other test equipment for checking continuity. Make sure that terminal
continuity is not wrongly simulated in reverse direction via current transformers or their short-circuiters.
– Remove the front cover.
– Remove the ribbon cable connected to the input/output board with the measured current inputs (on
the front side it is the right PCB, for housing size
Figure 3-4
– At the terminals of the device, check continuity for each pair of terminals that receives current from
the CTs.
– Firmly re-insert the I/O board. Carefully connect the ribbon cable. Be careful that no connector pins
are bent! Don't apply force!
– At the terminals of the device, again check continuity for each pair of terminals that receives current
from the CTs.
– Attach the front panel and tighten the screws.
•
Connect an ammeter in the supply circuit of the power supply. A range of about 2.5 A to 5 A for the
meter is appropriate.
•
Switch on m.c.b. for auxiliary voltage (supply protection), check the voltage level and, if applicable, the
polarity of the voltage at the device terminals or at the connection modules.
•
The measured steady-state current should correspond to the quiescent power consumption of the device.
Transient movement of the ammeter merely indicates the charging current of capacitors.
•
Remove the voltage from the power supply by opening the protective switches.
•
Disconnect the measuring test equipment; restore the normal power supply connections.
•
Apply voltage to the power supply.
•
Close the protective switches for the voltage transformers.
•
Verify that the voltage phase rotation at the device terminals is correct.
•
Open the miniature circuit breakers for the transformer voltage (VT mcb)
•
Check tripping circuits to the circuit breakers.
•
Check the close circuits to the power system circuit breakers.
•
Verify that the control wiring to and from other devices is correct.
206
correct (if used)?
4
correct (if used, e.g. with open delta winding or busbar voltage)?
4
slot 33) and remove the PCB so that there is no more contact with the plug-in terminal.
1 / see Figure 3-3 slot 19, for housing size
3
C53000-G1176-C159-5, Edition 05.2018
1 / see
2
SIPROTEC 4, 7VK61, Manual