Completing The Test; Thermal Overload Protection, Two Time Constants Trpttr; Checking Operate And Reset Values - ABB RET670 Installation And Commissioning Manual

1MRK 504 088-UEN C
13.6.5.2
13.6.6
13.6.6.1
Installation and commissioning manual

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.

Thermal overload protection, two time constants TRPTTR

Prepare the IED for verification of settings as outlined in section
section "Preparing for test"

Checking operate and reset values

Procedure
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 operate value
of stage IBase1, increase the current in phase L1 until stage IBase1 operates
and note the operate 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 as the operate and reset values of IBase1 for phases
L2 and L3.
5. Activate the digital input for cooling input signal to switch over to base
current IBase2.
6. Check for all three phases the operate and reset values for IBase2in the same
way as described above for stage IBase1
7. Deactivate the digital 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 L1 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.
11. Switch on the injection current and check that ALARM1 and ALARM2
contacts operate at the set percentage level and that the operate time for
tripping is in accordance with the set Time Constant 1 (Tau1).
With setting Itr = 101%IBase1 and injection current 1.50 · IBase1, the trip
time from zero content in the memory shall be 0.60 · Time Constant 1 (Tau1).
Verifying settings by secondary injection
in this chapter.
Section 13
"Overview" and
145