Topic 7 interconnected star and delta devices topic b7

Solve problems in single and threephase low voltage circuits

Topic 7: Interconnected Star and Delta
Devices


Star-Delta Configuration


Consists of a Star-connected supply driving a
Delta-connected load


Summary
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

20/02/17

Delta-connected load draws a HIGH phase current that
translates to a HIGHER line current that impacts directly
onto the phase current of the Star-connected supply (eg.
Transformer or alternator)
Note: Star-to-Star configuration means voltages and
currents are the same for supply as for the load.

Nathan Condie

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Star-Delta Configuration

20/02/17

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Delta-Star Configuration


Consists of a Delta-connected supply driving
a Star-connected load


Summary




20/02/17

Star-connected load draws a LOW phase current that
translates to the SAME line current that translates into a
LOWER phase current of the Delta-connected supply
(eg. Transformer or alternator)
Note: Delta-to-Delta configuration means voltages and
currents are the same for supply as for the load.

Nathan Condie

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Delta-Star Configuration

20/02/17

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Interconnected Star and Delta Devices


Relationships
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





20/02/17

Star-to-Delta produces a system that places HIGH

current demands on the supply system.
However, Star-connected supply allows
connection of unbalanced and single-phase loads.
Delta-to-Star produces a system that places LOW
current demands on the supply system.
However, Delta-connected supply is very
restricted in the types of loads that can be
connected.
Nathan Condie

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