Installing a fuse board on a boat

Discussion in 'Electricians' Talk' started by Ali553, Jul 16, 2021.

  1. Ali553

    Ali553 New Member

    Hi,

    I recently bought a cruiser however the electrics on the boat need to be updated as the the sockets and electrical power input is European.

    The boat is currently being fed from the dock by a 20 amp rcbo using a commando socket.

    I want to put in 2 x 20 amp breakers, 1 for the sockets and 1 for a water heater. Finally I want to install 1 x 10 amp breaker for lights.

    Using the dock for mcbo protection, i am considering installing mcbs for the different circuits and a 63 amp double pole switch.

    I did consider installing mcbos for the different circuits but I feel it could lead to nuisance tripping.

    I was then going to install a 16 amp RCD double pole switch as the main breaker but feeding an rcd from an rcbo may cause nuisance tripping.

    I could be most grateful if people could give me their thoughts. I know the 63 amp double pole will never trip but this is the only option I can see that may work.

    Thanks in advance.


    Al
     
  2. The Happy Builder

    The Happy Builder Screwfix Select

    The Wiring Regulations do not cover boat electrical installations, they cover the fixed installation in the marina supply the boat through the socket on the dock, but stops there.

    How are you going to generate electricity when you are cruising?
     
  3. Ali553

    Ali553 New Member


    The power is for when I am berthed at the marina. I have batteries which supply power when I’m cruising.
     
  4. Tony Goddard

    Tony Goddard Screwfix Select

    We had a maritime electrician on the other week with a land based question, hopefully he'll see this!
     
    Ali553 likes this.
  5. The Happy Builder

    The Happy Builder Screwfix Select

    Batteries supplying 240 volts AC through an inverter?
     
  6. Ali553

    Ali553 New Member


    I don’t have inverter just yet on the batteries but I plan to install one when I get the shore electrics wired up.
     
  7. Starslikedust

    Starslikedust Member

  8. Starslikedust

    Starslikedust Member

  9. MGW

    MGW Screwfix Select

    There are some special inverters which will top up shore supply when using more than available and recharge battery when surplus, you need to talk to a marine guy.
     
    Ind spark likes this.
  10. MGW

    MGW Screwfix Select

    Earthing is some times a problem, it can erode the catholic protection. Again rather special subject.
     
  11. The Happy Builder

    The Happy Builder Screwfix Select

    And a battery charger to top the batteries up whilst moored, plus a few solar panels up top.

    These boat installations get very complicated and you cannot install them as if they are a house.

    I’m a qualified electrician and I would not rush into wiring a boat.
     
  12. The Happy Builder

    The Happy Builder Screwfix Select

    That’s bonding, not earthing, there’s no where to put an earth rod under the boat all BS 7671 Wiring Regulations installations need a connection to true earth. That’s why boats aren’t included.

    As an electrician I can tell you some of the issues you need to consider, but I have never wired a boat and I know it is a completely different ballgame.
     
  13. just pumps

    just pumps Screwfix Select

    As a boat owner may I suggest a boat forum for expert advice rather than a shorebased forum.
     
    MGW likes this.
  14. The Happy Builder

    The Happy Builder Screwfix Select

    Such as, if you supply a boat with the propeller shaft bonded from a TNCS supply the propellor and shaft can rot away.
     
  15. Starslikedust

    Starslikedust Member

    Ocean-ing?
     
  16. Ali553

    Ali553 New Member

    Earthing a boat is tricky. If it’s not wired correctly and the hull of the boat becomes electric, you run the risk of making the water around the boat electric.

    i have purchased a galvanic isolator which will reduce the hull of the boat bring eroded. I will be installing this once I work out the best way to wire up the consumer unit on w boat.
     
  17. Ali553

    Ali553 New Member

    No the boat is moored on a river
     
  18. The Happy Builder

    The Happy Builder Screwfix Select

    I don’t think you should use a domestic consumer unit, I think you should be looking for a distribution board made for the job.
     
  19. Ali553

    Ali553 New Member

  20. Starslikedust

    Starslikedust Member

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