6. Measure the time delay for the TR1 signal and compare it with the set value.
7. Check the inverse time delay by injecting a voltage corresponding to 1.2 × U1>.
For example, if the inverse time curve A is selected, the trip
signals TR1 and TRIP operate after a time corresponding to the
equation:
IECEQUATION2429 V1 EN (Equation 99)
where:
t(s) Operate time in seconds
k1 Settable time multiplier of the function for step 1
U Measured voltage
U1> Set start voltage for step 1
8. Repeat the test for Step 2 of the function.
10.6.3.2  Completing the test
Continue to test another function or end the test by changing the TestMode setting to
Off. Restore connections and settings to their original values, if they were changed for
testing purposes.
10.6.4  Overexcitation protection OEXPVPH
Prepare the IED for verification of settings outlined in section 
"Preparing the IED to
verify settings".
10.6.4.1  Verifying the settings
1. Enable function.
2. Connect a symmetrical three-phase voltage input from the test set to the
appropriate connection terminals of the overexcitation protection OEXPVPH is
configured for a three-phase voltage input.
A single-phase injection voltage is applied if the function is configured for a
phase-to-phase voltage input.
OEXPVPH is conveniently tested using rated frequency for the injection voltage
and increasing the injection voltage to get the desired overexcitation level.
3. Connect the alarm contact to the timer and set the time delay tAlarm temporarily
to zero.
4. Increase the voltage and note the operate value V/Hz>.
5. Reduce the voltage slowly and note the reset value.
Section 10 1MRK 506 355-UEN A
Testing functionality by secondary injection
174 Line distance protection REL670 2.1 IEC
Commissioning manual