Siemens SIPROTEC 7SD610 Manual page 294

Mounting and Commissioning
3.2 Checking Connections
• 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 panel of the device (see Figure 3-3).
– Remove the ribbon cable connected to the I/O board (viewed from the front side it is the respective circuit
board on the right, see Figure 3-3). Then remove the printed circuit board so that there is no longer any
contact with the plug-in terminal of the housing.
– 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 po-
larity 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) and the power supply.
• 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.
• Check the signalling connections.
• Close the protective switches.
• If communication converters are used: check the auxiliary voltages for the communication converters.
• If the communication converter is connected to the communication network, its device-ready relay (DOK =
„Device Ok") picks up. This also signalizes that the clock pulse is recognized by the communication network.
Further checks are performed according to Section „Checking the Protection Data Topology".
• Please also observe carefully the documentation attached to the communication converters.
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SIPROTEC, 7SD610, Manual
C53000-G1176-C145-6, Release date 02.2011