Single phase and three phase?

Is this correct?

Standard residential panel (single phase)

Wye - Phase to phase is 240v

Phase to neutral-120v

Three phase power let's just say 480v

Wye- Phase to phase 480v

Phase to neutral 277

Delta- phase to phase 480v

Phase to ground 480v

Correct me if I'm wrong

1 Answer

  • qrk
    Lv 7
    2 months ago

    In a delta connection, neutral isn't used. A delta system is floating and the phase to ground should be zero volts (actual systems will measure something due to leakage resistance and capacitance). Earth ground will be supplied on delta feed, but this is only for safety.

    In North America, 3-phase wye is often 208V, not 240V, which gives you three 120V feeds (magic conversion factor of 1.73 {3^0.5}). Common in commercial buildings.

    Standard residential panel in North America is considered single phase. It's actually bi-phase since there are two 120V lines with 180° phase difference. Thus, you can have 120V or 240V for high power appliances.

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