Siemens siprotec SJ62 User Manual page 421

3 Mounting and Commissioning
419
• Check the functions of all test switches that are installed for the purposes of sec-
ondary testing and isolation of the device. Of particular importance are „test switch-
es " in current transformer circuits. Be sure these switches short-circuit the current
transformers when they are in the test mode.
• The short-circuit feature of the current circuits of the device are to be checked. This
may be performed with an ohmmeter or other test equipment for checking continu-
ity. 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
– Remove the ribbon cable connected to the I/O board with the measured current
inputs (on the front side it is the right printed circuit board). Furthermore, remove
the printed circuit board so that there is no more contact anymore with the plug-
in terminal of the housing.
– At the terminals of the device, check continuity for each pair of terminals that re-
ceives current from the CTs.
– Firmly re-insert the I/O board. Carefully connect the ribbon cable. Do not bend
any connector pins ! Do not use 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 con-
nection modules.
• The current input should correspond to the power input in neutral position of the
device. The measured steady state current should be insignificant. Transient move-
ment 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 con-
nections.
• 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 protective switches for the voltage transformers and the power supply.
• Check the trip and 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.
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015