Click for Westport Click for Abeking Click for JetForums Click for Northern Lights Click for Ocean Alexander

Isolation Transformer?

Discussion in 'Princess Yacht' started by Lazy Days, Dec 18, 2025.

You need to be registered and signed in to view this content.
  1. Lazy Days, Dec 18, 2025
    #1
    Lazy Days

    Lazy Days New Member

    Joined:
    Dec 2, 2025
    Messages:
    3
    Location:
    Tananger, Norway
    I have just bought a 1999 model Princess (Viking) 20M .

    This yacht does not have an isolation transformer on the shorepower circuit. Is it common practice not to have an isolation transformer?
  2. SplashFl, Dec 18, 2025
    #2
    SplashFl

    SplashFl Senior Member

    Joined:
    Feb 2, 2021
    Messages:
    691
    Location:
    S. Florida _ Bertram 46
    No idea if common or not but mine does not have one.
  3. ranger58sb, Dec 18, 2025
    #3
    ranger58sb

    ranger58sb Senior member

    Joined:
    Aug 20, 2013
    Messages:
    959
    Location:
    Chesapeake Bay, USA
    In our previous boat brand, they weren't commonly installed until circa 2003.

    -Chris
  4. Pascal, Dec 18, 2025
    #4
    Pascal

    Pascal Senior Member

    Joined:
    Feb 29, 2008
    Messages:
    8,802
    Location:
    Miami, FL
    Common on smaller boats especially from “budget” builders.
  5. Capt J, Dec 18, 2025
    #5
    Capt J

    Capt J Senior Member

    Joined:
    Jul 11, 2005
    Messages:
    14,776
    Location:
    Fort Lauderdale
    A lot of boats your size don't have isolation transformers. Keep in mind the builder is from England and they use different electricity there. So building for the American market wasn't something second nature for them as far as electricity goes at that time.
  6. rtrafford, Dec 22, 2025
    #6
    rtrafford

    rtrafford Senior Member

    Joined:
    Jul 13, 2019
    Messages:
    1,958
    Location:
    Vero Beach
    It's a good idea to plan to add one.
  7. Capt Ralph, Dec 22, 2025
    #7
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    14,131
    Location:
    Satsuma, FL
    Recent purchase of a 25 year old plastic boat.
    No isolation transformer.
    No purchase issues mentioned.
    IMO; I do not see a transformer needed.
  8. 993RSR, Jan 1, 2026 at 3:12 PM
    #8
    993RSR

    993RSR Senior Member

    Joined:
    Jan 15, 2004
    Messages:
    576
    Location:
    Annapolis/ Palm Harbor
    Forget about the IT, does she still have aluminum holding tanks? Likely they are long gone.
  9. Capt Ralph, Jan 1, 2026 at 6:35 PM
    #9
    Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    14,131
    Location:
    Satsuma, FL
    Thru my many years tinkering on boats, any steel or alloy black water tank is subject to a short life.
    Isolation Transformers (IT?) can not help here.
    Any builder of these tanks were obviously full of the affluent.

    Trying to type politely here; Even a Vegan tea totter's urine will eat up an alloy black water tank.
    alvareza likes this.
  10. Lazy Days, Jan 2, 2026 at 4:30 AM
    #10
    Lazy Days

    Lazy Days New Member

    Joined:
    Dec 2, 2025
    Messages:
    3
    Location:
    Tananger, Norway
    Still aluminium tanks - black water and fuel.