4. Close the switch to the station earth and check that the trip from the rotor
earth fault will be given after the set delay time.
5. Open the switch to the station earth and check that the trip signal resets
instantaneously.
6. Connect an adjustable resistor to the field circuit (221 on RXTTE4). Decrease
this resistor from a large value until the function operates and check
monitored value ICOSFI.
When the generator has been started the service value of injection voltage and
injection current shall be checked so that there is no risk for unwanted trip
due to large capacitive detected current.
15.9.2.2 Completing the test
Continue to test another function or end the test by changing the Test mode setting
to Off. Restore connections and settings to their original values, if they were
changed for testing purposes.
15.10 Secondary system supervision
15.10.1 Current circuit supervision CCSRDIF
Prepare the IED for verification of settings outlined in section
"Overview" and
section "Preparing for test" in this chapter.
The Current circuit supervision function CCSRDIF is conveniently tested with the
same three-phase test set as used when testing the measuring functions in the IED.
The condition for this procedure is that the setting of IMinOp is lower than the
setting of Ip>Block.
15.10.1.1 Verifying the settings
1. Check the input circuits and the operate value of the IMinOp current level
detector by injecting current, one phase at a time.
2. Check the phase current blocking function for all three phases by injection
current, one phase at a time. The output signals shall reset with a delay of 1
second when the current exceeds 1.5 · IBase.
3. Inject a current 0.9 · IBase to phase L1 and a current 0.15 · IBase to the
reference current input I5.
4. Decrease slowly the current to the reference current input and check that
blocking is obtained when the current is about 0.1 · IBase.
1MRK 502 029-UEN A Section 15
Verifying settings by secondary injection
209
Installation and commissioning manual
To Next Page
Loading...
