Windings - GE 845 Instruction Manual

TRANSFORMER
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Windings

6–4
lb Restraint (Ib Restr)
Range: 0.000 to 1000.000 x CT in steps of 0.001
Default: 0.000 x CT
lc Restraint (Ic Restr)
Range: 0.000 to 1000.000 x CT in steps of 0.001
Default: 0.000 x CT
la Differential 2nd Harmonic (Ia Diff 2nd Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
lb Differential 2nd Harmonic (Ib Diff 2nd Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
lc Differential 2nd Harmonic (Ic Diff 2nd Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
la Differential 5th Harmonic (Ia Diff 5th Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
lb Differential 5th Harmonic (Ib Diff 5th Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
Ic Differential 5th Harmonic (Ic Diff 5th Harm)
Range: 0.0 to 100.0% in steps of 0.1
Default: 0.0%
The values for differential and restraint currents are displayed in per times CT. The CT
primary, from the CT Bank assigned as Signal Input for Winding 1, is the reference CT
(base CT) used for estimating the differential and restraint currents. The winding reference
is explained in the Transformer Setup section.
The harmonic derating factor for each of the windings shows the effect of non-sinusoidal
load currents on the power transformer's rated full load current. The actual values
messages display the harmonic derating factor for windings 1 through 3.
The 845 displays winding load parameters as follows:
Path: Metering > Transformer > Windings
Metering\Transformer\Windings
Item Name
W1 Load (% of rated)
W1 Average Ph Current
W1 Harm Derate Factor
W2 Load (% of rated)
W2 Average Ph Current
W2 Harm Derate Factor
W3 Load (% of rated)
W3 Average Ph Current
W3 Harm Derate Factor
Windgs
Value
0.0
0.000
1.00
0.0
0.000
1.00
0.0
0.000
1.00
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 6: METERING
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