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What amount of amps should i have

Discussion in 'Technical Discussion' started by CAA450018, Jun 11, 2016.

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  1. CAA450018, Jun 11, 2016
    #1
    CAA450018

    CAA450018 New Member

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    Hello every one.
    I have a 1960 45 foot Connie, and am new to all this. I am in the beginning stage of rewiring the entire boat. At this time, its almost gutted so i believe its a good time to get the wiring installed and ready to hook up. I am thinking of installing a 125/240v 50amps. I see that most yachts have 2 to 3 electrical inlets on it. Why is this and what are they used for? Should i wire port and starboard on seperate lines? and if so, do i need two AC panel's. Any help would help. (I will not sell this later down the road, so not to worry. )
    Thanks for any help
  2. Capt Ralph, Jun 11, 2016
    #2
    Capt Ralph

    Capt Ralph Senior Member

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    There are a lot of issues that need to be addressed before anybody can offer a guess.
    It will be hard for anybody to give you a solid answer.
    Numbers of A/Cs or heaters, oven, water heaters, lighting and lots more.
    Port, stb, for & aft service inlets, transfer switches, service inlet breakers, GFI, Galvanic isolators, generators, chargers, inverters and bonding.
    You have to realize that you will be on this boat, using it and probably sleeping on it, maybe swimming around it. Family and friends included.
    With that in mind, there is no short cut or cheap way to do this. Especially when lives may depend on it.
    Please consult a surveyor or marine electrical consultant.
  3. menkes, Jun 12, 2016
    #3
    menkes

    menkes Member

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    Rcrapps, You're totaly right with your recommendation.
    Caa450018, In my profession i was an electrical power engineer (retired now), and designed electrical power systems simmilar to those you have in your yacht
    I can assure you there is much more than just running wires and inlets.
    My advise to you is not just consult the marine electrical consultent, but ask him to design the system, if not the detailed design.
    Please remember, you are dealing with high power/voltage, and electricity can kill !
  4. Sea Gull, Jun 12, 2016
    #4
    Sea Gull

    Sea Gull Member

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    Most modern boats of that size in the US would have one 50 amp/240 volt power connection. ( I'll probably get pushback on the voltage nomenclature , but in my experience, it's supplied at 208-240 volts). Maybe two, if you have some unusually high power uses, but I've never seen any boat with three power cords.

    In general, you'll use the 240 for a water heater, cooktop, HVAC units and pump, and maybe a battery charger. The lines then get split down to 2 x 120 v legs that power everything else.

    Please keep in mind that there are very specific requirement for wiring aboard a boat. This in not like wiring your home. not a job for an amateur.
  5. Pascal, Jun 12, 2016
    #5
    Pascal

    Pascal Senior Member

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    On a boat that size 120/240-50 is the way to go although some may suggest twin 120-30 as you may not have or need any 240 loads

    Multiple inlets may be an overkill on a 40 footer. The purpose is to reach shore power whether you are how in or stern in etc. if installing two inlets they will both feed a single panel using a rotary selector switch to select which one is used

    As others mentioned their are guidelines and rules you need to follow for safety and also so your boat pass survey and is insurable.
  6. ranger58sb, Jun 12, 2016
    #6
    ranger58sb

    ranger58sb Senior member

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    Ours is 50A/240V but we have no 220-240V appliances. The main supply is split into two 120V legs and everything runs on one or the other of those. We have spare capacity.

    I've seen some boats (few, not most) in this size range with a single panel but two inlets, one fore and one aft... presumably to add some flexibility when trying to reach shorepower connections.

    -Chris
  7. CAA450018, Jun 12, 2016
    #7
    CAA450018

    CAA450018 New Member

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    Hi rcrapps,
    thanks for the return, ok i will look into a pro for it.
  8. CAA450018, Jun 12, 2016
    #8
    CAA450018

    CAA450018 New Member

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    Hi Chris, Yes this is what i was looking to do. My idea was to split up the boat in sections. All led's lighting will be. Bow, gally, salon, eng rm, aft cabin, aft fuel,watr,steering room.. then all nav lights, spot\search lights, outside lights,nav equiptment all on its own lines. put additional brkers for the sections so if any thing goes wrong, it'll trip there and not extend to the main panels. all bilge pumps would be on its own circuit. Just wondered how i would break down the wiring at the main panels for the 50/240 and i have outlets/inlets on both sides.
  9. CAA450018, Jun 12, 2016
    #9
    CAA450018

    CAA450018 New Member

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    Hi, right understand, i just need to start setting up the proper wire size from panel to secondary breakers. Not connecting any thing yet. When its time to connect wire to all i'll have the pro to do it. I have a 45 footer.
    two rotary switches for the AC i didn't know but now do, thanks.
  10. CAA450018, Jun 12, 2016
    #10
    CAA450018

    CAA450018 New Member

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    hello, I'll have the wtr htr, hvac and the pumps, w/d and maybe the battery charger on a 240 line. every thing else on a 120.
    As to start connecting all wires, not ready and i won't do it, i'll get a pro in to finnish it up. I don't think i need a pro to come in a hang wire. That expense isn't justified.
  11. CAA450018, Jun 12, 2016
    #11
    CAA450018

    CAA450018 New Member

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    Hi , Ok it all sounds great, i'll talk to an electrician and have him her design one.
  12. RER, Jun 12, 2016
    #12
    RER

    RER Senior Member

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    Good luck getting a qualified sparky to come in and mess with your DIY stuff. When you have problems who will be responsible? No offense, but from your posts you sound wholly unqualified to do what you're going to be doing.
  13. CAA450018, Jun 12, 2016
    #13
    CAA450018

    CAA450018 New Member

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    Hello, Yes i do need to look into all this more. I was going to get the pro's help on my electric and just needed more information before i do it. I know some pros will bs me to purchase equipment i really don't need. Thanks for your input I do appreciate it.
  14. ranger58sb, Jun 12, 2016
    #14
    ranger58sb

    ranger58sb Senior member

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    Our system isn't particularly divided by area or location. Instead, the loads are balanced so each leg handles approximately the same amount of load. One fridge on each leg, on AC on each leg, cooktop on one leg and convection oven/microwave on the other, charger on one leg and water heater on the other, etc etc etc.

    And usually things like nav lights, electronics, exterior and some (most?) interior lighting and so forth would be DC loads, different animal from your AC side.

    Your marine electrician ought to be able to balance AC and DC loads easily enough...

    Ideally, have your pro designs your system first, have him specify wire sizes, ideally you both will pay attention to color codes s for future troubleshooting... and have him agree to what he wants you to pull where... before you start pulling or even buying wire. You only save money on the grunt work by doing it yourself if you do it right, ideally the first time.

    -Chris
  15. CAA450018, Jun 12, 2016
    #15
    CAA450018

    CAA450018 New Member

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    Thank you Chris, your advise is really appreciated. Will do this. For putting things on separate lines, its a redundant safety. Each section would have its own breaker panel for safety along with the main so if a short does come about it will stop short of burning the entire line if i didn't do it that way.. All my lights will be DC. Fridge AC/DC . Stove Electric.
  16. Capt J, Jun 13, 2016
    #16
    Capt J

    Capt J Senior Member

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    Just for the shorepower connection a single 50 amp 240 volt supply or shore power cable would be what I would normally recommend.