8. Primary and Secondary Voltage Ratings •
ANSI C84.1 defines acceptable voltage ranges for electrical systems in North America for all Classes o Primary = Medium Voltage o Secondary = Low Voltage Most common Primary Voltages per ANSI C84.1 o Wye 4 wire - 12.47 kV, 13.2 kV, 24.94 kV,
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34.5 kV systems
Delta 3 wire – 4.16 kV & 13.8 kV
o
Most common Secondary voltages per ANSI C84.1
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120/240V – Residential split-phase 208Y/120V – Muti residential premises (apartments, boat docks, etc.) 208Y/120V – Commercial three-phase wye
o o
o
480Y/277V – Industrial three-phase wye
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