be tested according to the corresponding instruction. Once this is done, continuewith the instructions below.If the current reversal and weak-end infeed logic for earth-fault protection isincluded, proceed with the testing according to the corresponding instruction aftertesting the communication logic for residual overcurrent protection. The currentreversal and weak-end-infeed functions shall be tested together with the permissivescheme.10.10.3.1 Testing the directional comparison logic function M13926-7 v2Blocking scheme M13926-9 v61. Inject the polarizing voltage 2U0 at 5% of UBase (EF4PTOC) where thecurrent is lagging the voltage by 65°.2. Inject current (65° lagging the voltage) in one phase at about 110% of the setoperating current, and switch the current off with the switch.3. Switch the fault current on and measure the operating time of thecommunication logic.Use the TRIP signal from the configured binary output to stop the timer.4. Compare the measured time with the set value tCoord.5. Activate the CR binary input.6. Check that the CRL output is activated when the CR input is activated.7. Switch the fault current on (110% of the set operating current) and waitlonger than the set value tCoord.No TRIP signal should appear.8. Switch the fault current off.9. Reset the CR binary input.10. Activate the BLOCK digital input.11. Switch the fault current on (110% of the set operating current) and wait for aperiod longer than the set value tCoord.No TRIP signal should appear.12. Switch the fault current and the polarizing voltage off.13. Reset the BLOCK digital input.Permissive scheme M13926-42 v8Section 10 1MRK 506 377-UEN CTesting functionality by secondary injection158 Railway application RER670 2.2 IECCommissioning manual
