Most Common Type of 50A Dockside Service?

Hello Dave-

Your boat can accommodate 60 amps at 120 volts (3 X 30) so if you normally run near that you want at least 50-60 amps. I thought you were aiming for a single cord with adapters so that would require a 50 amp cordset with adaptors at each end to power at different locations. If you do not want the heavier cord you are really 'stuck' with the two lighter ones at 30 each. If you would prefer to go with the heavier cord it would also be possible to change out one of your boatside inlets (the master one) to a 50 amp so you could then parallel off of that 50 - some internal wiring upgrades will likely be necessary to support the 50 amps to the twin breaker runs but that would be a one time deal. Another way is to extend the 50 amp line to the boat and then split it with a reverse "Y' into each inlet. Another thought is if you do go with a single 50 line to make up your own dockline that is longer than the typical 50' so you can reach further - I made mine 65' long. FWIW - there are some nice screw on covers which will block an unused leg of a 50/125 or 250 to two 30/125's that make them completely safe to use and removes the need to carry a straight version of the same adaptor.
In any case if you want to have more than 30 amps from any combination of sources there are plenty of options but you cannot avoid running more or heavier wires to get those added amps.

I have posted about this and our solution in another forum so I will find that again and post it below later. For us we really wanted to have a large amount of flexibility based upon the places we go and wanted as many options available to reach further power poles as well.

I hope this helps in some way or another - Ron
 
Here were our thoughts and solution to the dockside power options we went through a number of years back - this solution has worked perfectly for us since we bought the boat and made the changes....

Bayliner 4788 dockside power

There are many options available when deciding to add to your dockside power options but much of these choices can be dictated by where you will be using your boat. Although there has been a move to have upgraded dockside power available in recent years we still frequent marina’s, museums, and small docks which have limited power options and reward those with flexibility in connecting. Some of these destinations like Mystic Seaport as well as a few up the Hudson River will have longer dockside runs even if available as does Block Island on a busy weekend. So your ultimate decision to fit out your boat for dockside power should only be made after a careful look at how you may need you utilize it over future years.

Boat side

The 47XX with the A/C option ‘normally’ has 3 incoming lines labeled 1, 2 and 3 from the bow to stern on the starboard side. Lines 1 and 2 are utilized for all circuits other then A/C and heat and line 3 normally has 3 A/C units and 4 heaters on it as well as spares. Lines 1, 2 & 3 can be paralleled on the breaker panel with 2 switches which are: line #2 paralleled (P) on line #1 and line 3 P on line #1. By throwing one or both switches you can direct power that is brought to the boat on line #1 to either or both of lines 2 & 3. Please note that the max power available for all lines will be that which is brought to line #1. If you follow the graphic lines on the inside breaker panel you will get a feel for which line feeds which circuits and you can monitor your total amp load with the meters at the tops of the breaker strings.

Inlet configurations

‘Normally’ you will get 30amp/125 volt inlets on lines 1 & 2 and a 50amp/125 inlet on line 3 with the A/C and genset option. Many of these have been rewired at the dealer and/or with previous owners so checking exactly what you may have at the inlet and behind the panel (wire gage and switch config.) is a mandatory 1st step. You will likely find that all wires from the inlets to the switches and breaker panel bus lines are 8 gage or better but there have been some observed to be 10 - gage (30 amp max) in some re-wires.

Options

It is not too difficult to change a boats inlet as long as you are capable of ensuring that the wiring and breakers behind it can support the new amperage. It is also fairly easy to buy many premade dockside lines and adapters as long as the expense is considered. You can reasonably estimate your power needs by watching and recording your actual amperage usage at 125 volts with the meters at the tops of the 3 breaker lines while you use your boat. Turn on all electrical appliances that you wish to connect and add up the 3 lines for a total (note - when paralleled meter 1 will read a sum of what is paralleled at that time). What is more difficult to figure is the dockside power that will be available for you to hook up to when you are visiting specific destinations.

Our solution (certainly not the only one)

We have chosen to go with a very flexible solution since we see many varying dockside power where we cruise each year. Our goal was to have the ability to hook up to whatever power was available and have the potential dock line runs be very long for crowded or limited marina’s. Our boat came with the ‘normal’ 30/125 inlets on line 1 & 2 and a 50/125 on line #3. It also came with 2-30 amp 50' dockcords as well as 2-50amp/125 by 50' dockcords and an adapter or two. We changed the inlet on line #1 to a 50/125 and made sure that the supporting hardware was up to the task (it was). We then made a 65' long 50 amp/250 volt dockside line from underwater rated mining cable with the associated ends to feed a 50/250 (dockside) to 50/125 (boatside) “Y” adapter that we purchased. We also have 2 single adapters that are 30amp dock to 50/125 boatside as well as an adapter that is 15 amp dock to 30 amp boatside.

Some common marina hook-ups for us (there are many more)

Preferred is a 50/250 dockside tower that we hook our 50/250 cable to and run to the boat through our 5/250 “Y” to lines 1 & 3. We parallel line 1 & 2 and this gives us 50/125 on lines 1 & 2 and 50/125 on line 3 which pretty much can power everything at once ( well not quite - but close).

Next is a 30 amp tower that also has 50/125 available - we run one 30 to line 1 & 2 “P” with the single adaptor and the 50 to line 3 with the 50/125 cord. We now have 80 amps at125 available and can add the other dockcord lengths to the run if necessary.

Another is a 2-30 amp dockside tower - we run 2-30 amp dockcords through the 2 single 30 amp to 50/125 adapters to lines 1 & 3 (1 & 2 are “P”). This gives us a total of 60 amps/125 at the boat.

So there are many possibilities on how this can be configured based upon your cruising needs.
Hope this helps. Ron & Karen “No Worries”
 
I will say the 30A lines are much easier to haul around. MUCH EASIER.
 
When you double the voltage you draw less amps. P=E x I
My boat is a huge power hog, have 220v devices, 110 devices, 24 volt dc, and 12 volt dc. If I go to a place that only has dual 30 amp service I need a "smart Y" and need to have different phases to generate the power required for my boat, major pain in the butt!!!!
 
"When you double the voltage you draw less amps. P=E x I"

Yes - but you are drawing them on two legs so you need an extra wire in the run.
As Dan pointed out multiphase motors are more efficient but must have two phases to use.
Once you are using two phase power you often must have smart "Y"'s and in some cases and in some places things cannot be used at all.
 
quote:
Originally posted by boatbum

I will say the 30A lines are much easier to haul around. MUCH EASIER.

Click to expand...


Are 2 30 amp lines really easier to handle than a single 50? I know the 50 is heavier than a 30, but in a 25' length (what I use) I'd think that it'd be easier than jockeying a pair. It'd certainly be cheaper as I already have a practically brand-new 30, so I'm willing to be convinced
 
"Are 2 30 amp lines really easier to handle than a single 50?"

I am sure it is a personal preference so I can only give you one opinion as mentioned above our preference is one line. A 50 is a lot heavier but not a big deal for us to run one line and look for one good outlet on the dock. They are a lot more expensive as well but then I 'get' 100 amps with one line run.

I am sure your boating style and boating destinations will help you decide. How many amps do you really need?

Hope this helps
 
I do not like the way the 30 amp cords hang off the power posts and off the side of the boat. I have changed many burned receptacles or plugs. You have all seen them hanging on the receptacle because there is only one hooked spade. Imo, it is a terrible design.
If money is available you should upgrade to 50 amp 250 volts. This includes the wiring from your point of attachment all the way to your panel. You also need to make sure your panel is two pole as you now have two hot legs instead of one. The main breaker also needs to be 50 amp, two pole.
These poa connections have two twist spades and a much stronger lock in. Once you get all the adapters for what ever dock hookups you have, you're all set. I have also noticed the marinas as they upgrade are changing out to 50/250, so you will need to use adapters less in the future.

Billy K.
 
I did some research to see if upgrading the whole shebang would be a good idea. I mean, it is a good idea, but definitely cost prohibitive in my case. My panel won't support it, and I'd be getting into some pretty pricey stuff to replace it all. Running an additional 30 for the new air conditioning is much, much cheaper.
 
After finally finding the comparative weights of 50- vs 30-amp cables, I decided to go with 2 30's. Danged 50-amp weighs 50% more than a pair of 30's, and 90% of the time I only need a single 30, to run the house stuff. So, I'll get a second 30 amp cord, a 50(250/125) to two 30's y-adapter, and a 30 to two 30's y-adapter. I already have 115v adapters (very rarely used). Places like WH that require the oddball, also rent them so I'll hold off on that unless/until I see a great deal on Craigslist.

Thanks for the insight and advice, folks!
 
quote:
Originally posted by CurrentSea

Only Watch Hill and Sailors are 50/125 service which is different than 50/250 service.
Most other places are 50/250 or 30/125 and the 30/125 is sometimes 2 outlets and sometimes 1.
I think Cedar gives you 1.

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Just wanted to close out this thread with some info I've learned. CurrentSea, after receiving some conflicting info about Cedar I called Babylon Parks Dept. I specifically asked them whether the 50 amp supply there was 125V or 125/250V. I was told that Cedar's 50 amp service is 125V, NOT 125/250. Also rode over to my new slip at Tanner Park (I'm launching next Wednesday) and found out they supply only 20 amps at the dock as I assume they try to limit electric use there.

After all that I put together the following (some of which I already had)...

(1) 30-amp cord (stays at the slip)
(1) 20-amp male to 30-amp female adapter for the slip

(2) 30-amp, 25' travel cords that stay with the boat.
(1) 30-amp male to 2-30 amp female y-adapter
(1) 50-amp/125V male to 2 30 amp female y-adapter
(1) 50-amp 125/250V male to 50 amp 125V female pigtail adapter for the above y-adapter to convert it for 125/250V power supply. Got a decent deal on eBay.

All stupidly expensive, of course.

I also have a couple of adapters around to mate a 30-amp cable to a 115V outlet, and to mate a 115V extension cord to a 30 amp inlet on the boat.

Hope I have it all now- time will tell :-)
 
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