1 The Utility Breaker Tim Heard DDC Engineer AEP Texas SWEDE 2006
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The Utility Breaker Tim Heard DDC Engineer AEP Texas SWEDE 2006
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Introduction
A Utility Breaker is a spare breaker that can be used as a:
Feeder replacement breaker Totalizing breaker Bus tie breaker
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History
Mid 1960’s-CPL began installing utility breakers
1994- Utility breakers removed from substation design standard
Today- 41 Utility breakers available for service in TCC (old CPL)
0 Utility breakers in TNC (old WTU)
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SCADA 1-LINE OUT OF SERVICE
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SCADA 1-LINE AS FDR REPLACEMENT
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SCADA 1-LINE AS TOTALIZER
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SCADA 1-LINE AS BUS TIE
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PICTURE OF SWITCHES
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PICTURE OF SWITCHES
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PICTURE OF SWITCHES
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PICTURE OF CONTROL PANEL
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PICTURE OF SELECTOR SWITCH
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Relay Transfer Switch
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Relay Transfer Switch Operations
Utility Breaker CT secondaries are switched to Utility Breaker overcurrent relays.
Utility Breaker relay trips are switched to Utility Breaker trip coil.
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Relay Transfer Switch Operations
Utility Breaker CT secondaries are switched to #3 Transformer Differential Relays and #3 Transformer Totalizing relays.
#3 Differential trips and Totalizing trips are switched to Utility Breaker trip coil.
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Relay Transfer Switch Operations
Utility Breaker CT secondaries are shorted.
Utility Breaker overcurrent relay trips remain switched to Utility Breaker trip coil.
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Utility Breaker Cost
Installation costs is 40%-50% higher than feeder breaker due to: 1- Utility Breaker or 2- Feeder
Breakers can fit in standard 20’x20’ bay
Breaker, risers, and switches rated for 2000 amps vs. 1200 amps
More cable work for CT and trip circuits
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BENEFITS
Huge impact on SAIDI/ CAIDI when dealing with Substation related outages
Time/ Labor savings in switching for routine maintenance
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Questions?