If the neutral VT is not available, then the setting NeutVoltMeas is set to Not available.
1. Set the following parameters:
• Operation = Enable
• tDefWrn =5 s; tDefAlm =5 s; tDefTrip =5 s
• SCBGndType =Ungrounded
• NeutVoltMeas =Not available
• Udif> =10% UB
• UdifAlm> =8% UB
• UdifWrn> =5% UB
• UMin> =50% UB
• VoltRatioL1 =0.5
2. Activate RESETCOMP input to ensure that the stored values are reset.
3. The expected output is monitored in the following path from the local HMI client: Main menu /Test/
Function status /Unbalance protection/CapBankPhaseVoltageDiff(87V, Ud>)/SCPDPTOV(87V,
Ud>):x/Outputs , where x = instance number.
4. check the respective operation of warning, alarm, and trip.
Step no. Changes after step 2 Expected output
4-a* Inject constant bus voltages of U
L1
= 60 V at 0°,
U
L2
= 60 V at 240°, and U
L3
= 60 V at 100° in
secondary at rated frequency
• UL1, UL2, and UL3 should show 218.18
kV
• UNSCB should show 6.94kV
4-b Inject constant tap voltage of U
TapL1
= 30 V in
secondary at rated frequency
UTAPL1 should show 109.09 kV
RESETCOMP Test
4-c Activate binary input RESETCOMP for 1 s USEDURATL1 should show 0.5 (VoltRatioL1)
TRIGCOMP Test
Repeat Sub-step 4–a
4-d Inject U
TapL1
= 28.17 V in secondary at rated
frequency
• DIFURATL1 should become HIGH
• URATIOL1 and USEDURATL1 should
show 0.4 and 0.5 respectively
4-e ** Activate binary input TRIGCOMP for 1 s • The output COMPEXED should become
HIGH for 100 ms and LASTCOMP output
should display the date and time of
compensation
• URATIOL1 and USEDURATL1 should
show 0.4
• DIFURATL1 should become LOW
WARNING Signal Test
4-f Inject U
TapL1
= 29.50 V in secondary at rated
frequency
• WARNING and WRNL1 signals should
become HIGH after a time delay given by
the setting tDefWrn
• PUDIFL1 should show 5.28 %
ALARM Signal Test
Repeat Sub-step 4–a and Sub-step 4–b
4-g Inject U
TapL1
= 30.20 V in secondary at rated
frequency
• ALARM and ALML1 signals should
become HIGH after a time delay given by
the setting tDefAlm
• PUDIFL1 should show 8.06%
Table continues on next page
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 225
Commissioning manual
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