Transcript Ins_coord_2

INSULATION COORDINATION
COURSE
ELEC. ENG. DEPT.
SHARIF U. of T.
MEHDI VAKILIAN
MAY 2009
INSULATION COORDINATION
Specifying Insulation Strength
In Standards
- There exist a standard number series for
both BIL & BSL that equipment standards
are encouraged to use
- For any specific equipment there is a
relation between BIL & BSL
- For example for a transformer, BSL is
approximately 83% of BIL
INSULATION COORDINATION
Specifying Insulation Strength
In Standards
INSULATION COORDINATION
 Specifying
Insulation Strength
In Standards
 In IEC phase-phase tests are specified to
verify phase-phase BSL
 The phase-phase BSL is specified as 1.5
to 1.7 phase-ground BSL
 In this case BSL are not the values listed
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INSULATION COORDINATION
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ANSI Specification for BIL and BSL
INSULATION COORDINATION
 Specifying
 In
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Insulation Strength
Standards
In ANSI C92, no required voltage given for
alternate system voltages
That is user is free to select BIL & BSL from as
desired
However, practically there are a limited number
of BILs and BSLs used at each system voltage
INSULATION COORDINATION
 Specifying
 In
Insulation Strength
Standards
 for USA these values presented in
next tables for transformers, circuit
breakers, and disconnecting switches
INSULATION COORDINATION
ANSI
Table:
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INSULATION COORDINATION
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ANSI standard values for substations (ANSI)
INSULATION COORDINATION
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For Gas-insulated station (ANSI)
INSULATION COORDINATION
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ANSI standard levels for Cables
INSULATION COORDINATION
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Specified insulation withstands in In IEC standards