Section 4
1MRK 511 434-UEN A
Commissioning SAM600
42
SAM600 Process Bus I/O System
Operation Manual
Primary injection test to verify the current ratio of the CT, the correct wiring up
to SAM600-CT and correct phase sequence connection (L1, L2, L3, and L4).
Polarity check to prove that the predicted direction of secondary current flow is
correct for a given direction of primary current flow.
CT secondary loop resistance measurement to confirm that the current
transformer secondary loop DC resistance is within specification and that there
are no high resistance joints in the CT winding or wiring.
CT excitation test in order to confirm that the current transformer is of the
correct accuracy rating and that there are no shorted turns in the transformer
windings. Manufacturer’s design curves must be available for the current
transformer to compare the actual results.
Earthing check of the individual CT secondary circuits to verify that each
three-phase set of main CTs is properly connected to the station earth and only
at one electrical point.
Insulation resistance check.
Phase identification of the CT shall be made.
Both the primary and secondary sides must be disconnected from
the line and the SAM600-CT when plotting excitation
characteristics.
If the CT secondary circuit earth connection is removed without the
current transformer primary being de-energized, dangerous voltages
may result in the secondary CT circuits.
Verifying the power supply
Check that the auxiliary supply voltage from the DC/DC converter remains within
permissible input range under all operating conditions. Check that the polarity is
correct before powering on a SAM600 system.
Verifying binary inputs
Check all connected signals and auxiliary supply voltage so that both input level
and polarity are in accordance with the SAM600 module specifications.
Verifying communication connections
Check that SFP modules are plugged in correctly in the SFP cages and are locked.
Check that Tx and Rx optical connections on ST connectors (towards bay level
protection and control devices) are correct.
Check that the minimum bending radius for optical fibers is in
accordance with the cable manufacturer’s specifications.
