Shorepower

Discussion in 'Electrical Systems' started by Swimpy, Nov 19, 2006.

Page 2 of 2
  1. Carioca
    Joined: Aug 2005
    Posts: 82
    Likes: 2, Points: 0, Legacy Rep: 26
    Location: BRAZIL

    Carioca Junior Member

    "The whole issue may be side-stepped by installing an Isolating Transformer."

    Not quite, specially if your boat is on the hard.
    The grounding plate on the hull will be required to discharge through .........the air ?
     
    Carioca, Jan 22, 2007
    #16
  2. jehardiman
    Joined: Aug 2004
    Posts: 3,773
    Likes: 1,167, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    You are correct, in low density power areas residential and lighting is 240/230-120/115 3 wire pulled off one of the phases in a transformer (with an inversion to get two phases out) of the high voltage 3 phase distribution lines. Here on the shipyard and in large bulidings/high density power areas it is 220/208-120 4 wire. But then again, it depends on who you ask wether 208/220 and 230 are called 240 and 115 is 120 (i.e. in a "120" volt system the peak voltage is 170, the rms voltage is 120 and the current rating voltage assumes a 5% loss for a voltage of 114).
     
    jehardiman, Jan 23, 2007
    #17

  4. M&M Ovenden
    Joined: Jan 2006
    Posts: 365
    Likes: 80, Points: 38, Legacy Rep: 527
    Location: Ottawa

    M&M Ovenden Senior Member

    Hi,

    I realize that most people consider 208/220/230/240 the same voltage, but to do so is sloppy. 220/230/240 is from a single phase source, where 208 is from a 3 phase supply. if 220 was from 3 phase power each leg would have a voltage of: 220 / (2*sin120) = 127V . In your shipyard you will find that you have 3 phases of 120V, which gives a phase-phase voltage of 208. This can fluctuate from location to location, but the voltage ratios will always be the same.

    Cheers,
    Mark Ovenden
     
    M&M Ovenden, Jan 24, 2007
    #18
Page 2 of 2
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.