Basler BE1-CDS220, Instruction Manual

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D-10 Settings Calculations BE1-CDS220
tap times 098 . 0 024 . 0
39
20
1 25 . 0
= − 





− ∗ =
o
M
Equation D-22
If the conservative calculation yielded a margin < or = 0, the minpu and/or the slope settings should be
increased.
Step 5: Convert the margin to primary amperes. As a reality check, convert the margin to high side
and low side primary amperes. The equation to do so is similar to Equation D-8.
kV 69 @ A 4 . 16
1
60 79 . 2 098 . 0
=
∗ ∗
=
Ipri
Equation D-23
kV 12.47 @ A 08 . 90
1
160 79 . 5 098 . 0
=
∗ ∗
=
Ipri
Equation D-24
Harmonic Restraint Settings
The recommended harmonic restraint settings have been in effect successfully for many years. Most
applications should use these settings. When second harmonic sharing is enabled, restraint for the A
phase differential element is determined by:
Setting Restraint 2nd 100
1
2 2 2
≥








+ +
st op
nd op nd op nd op
IA
IC IB IA
The B phase and C phase differential elements respond similarly with IB
op1st
and IC
op1st
substituted in the
respective equation. This unique method of second harmonic sharing is recommended to ensure proper
restraint on all phases without blocking tripping on faulted phases.
For special transformers cases, contact the transformer manufacturer or the Basler Electric Technical
Services Department.
Step 1: If second harmonic sharing is enabled, set the second harmonic restraint unit setting at 18%.
If second harmonic sharing is disabled, set the second harmonic restraint unit at 12%.
Step 2: Set the fifth harmonic restraint unit setting.
5
th
= 35%