Checking Ct Circuits; Checking Vt Circuits - ABB ret650 Commissioning Manual

Section 3
Starting up
3.7
3.8
26
Be sure to set the correct technical key in the IED and PCM600 to
prevent writing an application configuration to a wrong IED.
See the engineering manual for information on how to create or
modify an application configuration and how to write to the IED.

Checking CT circuits

Check that the wiring is in strict accordance with the supplied connection diagram.
Correct possible errors before continuing to test the circuitry.
• Primary injection test to verify the current ratio of the CT, the correct wiring
up to the protection IED and correct phase sequence connection (that is L1,
L2, L3.)
• 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.
• 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.
CT and VT connectors are pre-coded, and the CT and VT connector
markings are different. For more information, see the installation
manual.
Both the primary and the secondary sides must be disconnected
from the line and the IED when plotting the excitation characteristics.

Checking VT circuits

Check that the wiring is in strict accordance with the supplied connection diagram.
Correct possible errors before continuing to test the circuitry.
1MRK 504 126-UEN -
Commissioning Manual