ABB Relion 670 series - Page 225

• IUnbalAlm> = 20% IB2
• IUnbalWrn> = 10% IB2
• IMin = 10% IB1
2. The logical signals and service values for SCUCPTOC function are available on the local HMI under:
Main menu/Tests/Function status/Unbalance protection /CapBankCurrentUnbalance(60N,
Iub>)/SCUCPTOC(60N, Iub>):x/outputs , where x = instance number.
3. To store the unbalance current values, perform these steps:
Step No. Changes after step 1 Expected output
3-a Inject constant currents* of I
A
= 1∠0° A, I
B
=
1∠240° A, and I
C
= 1∠120° A in secondary at
rated frequency.
IA, IB, and IC should show 1000 A
3-b Inject I
UNBA
= 0.2∠0° A, I
UNBB
= 0.2∠0° A, and
I
UNBC
= 0.2∠0° A in secondary at rated
frequency
IUNBA and IUNBCLC_A should show 2 A
IUNBB and IUNBCLC_B should show 2 A
IUNBC and IUNBCLC_C should show 2 A
3-c** Activate binary input TRIGCOMP for 1 s • The output COMPEXED should become
HIGH at 100 ms
• The output LASTCOMP should display the
date and time of compensation
The following outputs should show the mentioned
values:
• IMEM_A, IMEM_B, and IMEM_C should
show 1000 A
• IMEMUNB_A, IMEMUNB_B, and
IMEMUNB_C should show 2 A
• IREFUNB_A, IREFUNB_B, and IREFUNB_C
should show 2 A
• IUNBCLC_A, IUNBCLC_B, and IUNBCLC_C
should show 0 A
* - CT ratios of the phase currents (1000/1 A) and unbalance currents (10/1 A). The values of IB1 and IB2 are
considered as 1000 A and 10 A, respectively. The current inputs I
A
, I
B
, and I
C
refer to the phase current inputs and
I
UNB_A
, I
UNB_B
, and I
UNBC
refers to the unbalance current inputs.
** - This step should be done only during Factory Acceptance Test (FAT). At field, the testing should be done with
the stored field values.
4. Check the respective operation of warning, alarm, and trip.
Step No.
Changes after step 3 Expected output
WARNING TEST
4-a Retain constant currents* of I
A
= 1∠0° A,
I
B
= 1∠240° A, and I
C
= 1∠120° A in
secondary at rated frequency.
Change** I
UNBA
= 0.35∠0° A, I
UNBB
=
0.35∠0° A, and I
UNBC
= 0.35∠0° A
WARNING, WRNA, WRNB, and WRNC signals should
become HIGH after the set time delay
IUNBA, IUNBB, and IUNBC should show 3.5 A
IUNBCLCA, IUNBCLCB, and IUNBCLCC should show 1.5
A which is equivalent to 15% of IBase2
ALARM TEST
4-b Change I
UNBA
= 0.45∠0° A, Change
I
UNBB
= 0.45∠0° A, and Change I
UNBC
=
0.45∠0° A,
ALARM, ALMA, ALMB, and ALMB signals should become
HIGH after the set time delay
IUNBA, IUNBB, and IUNBC should show 4.5 A
IUNBCLCA, IUNBCLCB, and IUNBCLCC should show 2.5
A which is equivalent to 25% of IBase2
Table continues on next page
1MRK 504 165-UUS Rev. J Section 11
Testing functionality by secondary injection
Transformer protection RET670 219
Commissioning manual
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