1MRK 504 165-UEN Rev. K
Step No.
6-b
6-c
* - 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
inputs and I
To calculate IREFUNBL1 in
IREFUNBL1
IECEQUATION19378 V1 EN-US
To calculate IUNBCLCL1 in
IUNBCLCL1 IUNBL1 IREFUNBL1
IECEQUATION19377 V1 EN-US
Testing with 3 Unbalance Curr option
1.
Set the following parameters:
•
•
•
•
•
•
•
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:
Transformer protection RET670
Commissioning manual
Changes after step 5
Change I
= 0.45∠0° A
UNBL1
Change I
= 0.55∠0° A
UNBL1
refers to the unbalance current inputs.
UNBL1
Step
5-c, use the following equation:
IL1
=
´
IMEMUNBL1
IMEML1
Step
6, use the following equation:
=
-
The measured unbalance current is referred with respect to its reference current.
Refer Technical manual for more information about unbalance current calculation.
Operation = ON
SCBConf = 3 unbalance curr
tDefTrip = 5.00 s; tDefAlm = 5.00 s; tDefWrn = 5.00 s
IUnbal> = 30% IB2
IUnbalAlm> = 20% IB2
IUnbalWrn> = 10% IB2
IMin = 10% IB1
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Expected output
ALARM and ALML1 signals should become HIGH after
the set time delay
IUNBL1 = 4.5 A
IUNBCLCL1 = 2.5 A which is equivalent to 25% of
IBase2
START and TRIP TEST
•
START and STL1 signals should become HIGH
•
TRIP and TRL1 signals should become HIGH
after the set time delay, if BlockTrip is set to Trip
enabled
IUNBL1 = 5.5 A
IUNBCLCL1 = 3.5 A which is equivalent to 35%
of IBase2
, I
, and I
L1
L2
Section 11
Testing functionality by secondary injection
refer to the phase current
L3
(Equation 106)
(Equation 107)
GUID-C028CACA-D487-4DD1-B7CA-92219F3A41F0 v1
207