Completing The Test; Thermal Overload Protection, Two Time Constants Trpttr (49); Checking Trip And Reset Values - ABB RET670 Commissioning Manual

Section 11
Testing functionality by secondary injection
11.5.6.2
11.5.7
11.5.7.1
190
4. Inject a voltage 0.8 · VNRelPU and a current high enough to trip the directional
function at the chosen angle.
5. Increase the voltage until the directional function is released.
6. Compare the measured value with the set VNRelPU trip value.

Completing the test

Continue to test another function or end the test by changing the TESTMODE setting to
Disabled. Restore connections and settings to their original values, if they were changed
for testing purposes.

Thermal overload protection, two time constants TRPTTR (49)

Prepare the IED for verification of settings outlined in Section
verify settings".

Checking trip and reset values

1. Connect symmetrical three-phase currents to the appropriate current terminals of the
IED.
2. Set the Time constant 1 (Tau1) and Time Constant 2 (Tau2) temporarily to 1 minute.
3. Set the three-phase injection currents slightly lower than the set trip value of stage
IBase1, increase the current in phase A until stage IBase1trips and note the trip
value.
Observe the maximum permitted overloading of the current circuits
in the IED.
4. Decrease the current slowly and note the reset value.
Check, in the same way, the trip and reset values of IBase1 for phases B and C.
5. Activate the cooling input signal, thus switching to base current IBase2.
6. Check the trip and reset values (for all three phases) for IBase2 in the same way as
described above for stage IBase1.
7. Deactivate the input signal for stage IBase2.
8. Set the time constant for IBase1 in accordance with the setting plan.
9. Set the injection current for phase A to 1.50 · IBase1.
10. Connect a trip output contact to the timer and monitor the output of contacts
ALARM1 and ALARM2 to digital inputs in test equipment.
Read the heat content in the thermal protection from the local HMI and wait until the
content is zero.
1MRK 504 165-UUS -
"Preparing the IED to
Transformer protection RET670 2.2 ANSI
Commissioning manual