IECEQUATION19376 V1 EN-US (Equation 112)
Verifying the function in Ungrounded mode
GUID-069FCF45-61B1-486C-8C0E-D1CC66B3BB3F v1
The following procedures are performed to test the function in Ungrounded mode.
If there is a VT present in the neutral, then the setting NeutVoltMeas is set to available.
1. Set the following parameters:
• Operation = Enable
• tDefWrn = 5 s; tDefAlm = 5 s; tDefTrip =5 s
• SCBGndType = Ungrounded
• NeutVoltMeas = 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
= 63.51
V at 0°, U
L2
= 63.51 V at 240°, and U
L3
=
63.51 V at 120° in secondary at rated
UL1, UL2, and UL3 should show
230.94 kV
4-b Inject constant tap voltage of U
TapL1
=
31.75 V in secondary at rated frequency
UTAPL1 should show 115.47 kV
4-c Inject constant neutral voltage of U
N
= 1 V
in secondary at rated frequency
UNSCB should show 36.63 kV
RESETCOMP Test
4-d Activate binary input RESETCOMP for 1 s USEDURATL1 should show 0.5
(VoltRatioL1)
TRIGCOMP Test
Repeat Sub-step 4–a
4-e Inject U
TapL1
= 31.75 V in secondary at
rated frequency
• DIFURATL1 should become
HIGH
• URATIOL1 and USEDURATL1
should show 0.492 and 0.5
respectively
Table continues on next page
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 223
Commissioning manual
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