Dual 50amp/125v inlets to single 50amp/250-gctid821074

[Cool_Beans]

I'd like to replace my mess of 50-30amp adapters on the the boat going to 30 amp cords to a 30-50amp y-adapter to the dock supplied 50/250v with a single 50/250v Smart Plug. Boy, if anything screams "fire hazard"....

Being a live aboard, I can pull some amps! Yes, I juggle when needed. If understand this correctly, going to 50/250 means I'll have 100 amps @ 125v available?

So! Has anyone performed this conversion? And how easy was it? In my head it should be grounds and neutrals go to their own terminals and each hot goes to it's own terminal...but this is a boat project, so I assume it is more complicated than that :S

Thanks!

EDIT: My boat has dual 50/125v inlets which has lead to a number of adapters and connections outside the boat.

[smitty477]

'going to 50/250 means I'll have 100 amps @ 125v available?"

Yes

"So! Has anyone performed this conversion?"

Yes

"And how easy was it?"

It depends - if you are going to wire your boat to accept a 50 amp plug and source you need to make sure that all the wiring and switches are rated for at least 50 amps.

In our case with our 4788 that was the case - all the wires and switches after the boat inlet(s) and prior to the distribution panel could all support the 50 amps. If not you will need to rework the panels and wires such that they are safe with the 50 amps.

Or - perhaps you do not mean to pull the 50 amp wires and connections to the boat rather you will have 30 amp connectors on the boat side?

In that case you can leave your 30 amp wiring and just make sure your 30 amp breakers on board are in good shape. That will give you two 30 amp legs at 125 volts or 60 amps total not 100 amps.

Here is an older post we made:

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"

[Cool_Beans]

"smitty477" post=821078 wrote:
'going to 50/250 means I'll have 100 amps @ 125v available?"

Yes

"So! Has anyone performed this conversion?"

Yes

"And how easy was it?"

It depends - if you are going to wire your boat to accept a 50 amp plug and source you need to make sure that all the wiring and switches are rated for at least 50 amps.

In our case with our 4788 that was the case - all the wires and switches after the boat inlet(s) and prior to the distribution panel could all support the 50 amps. If not you will need to rework the panels and wires such that they are safe with the 50 amps.

Or - perhaps you do not mean to pull the 50 amp wires and connections to the boat rather you will have 30 amp connectors on the boat side?

In that case you can leave your 30 amp wiring and just make sure your 30 amp breakers on board are in good shape. That will give you two 30 amp legs at 125 volts or 60 amps total not 100 amps.

I assume (yes, yes, I know...) my panels are 50 amps each since I have 50/125v service inlets boat side? I thought I read somewhere that if you had the "power hungry boat option" (microwave, dual AC/Heat, 3 base baord heaters, electric range, water heater, etc.) you could get the 2 x 50/125v upgrade.

thanks!

[smitty477]

"I assume (yes, yes, I know...) my panels are 50 amps each since I have 50/125v service inlets boat side? I thought I read somewhere that if you had the "power hungry boat option" (microwave, dual AC/Heat, 3 base baord heaters, electric range, water heater, etc.) you could get the 2 x 50/125v upgrade."

The 38 Bayliner typically had two 30 amp/125 inlets.

Are your main breakers on the boat 30 amps or 50 amps?

Typically they wired the AC units and the heaters on line 2 and everything else on line one.

Two AC units on the 38 (usually a 12 and a 16K BTU) would draw less than 25 amps or so.

Typically a water heater is 5 amps or so, a microwave maybe 5-7 amps and a range might be 10-15 amps or so.

If you are not sure what wire grade is behind the boat inlets now is a really good time to check.

[Cool_Beans]

Hmmm, I'll check that out. IIRC, it's almost set up as fore and aft.

Line 1 has the salon AC, fridge, range, icemaker, battery charger, forward outlets, and a heater.

Line 2 has the forward AC, 2 heaters, aft outlets, microwave, water heater, and 2 not used.

I've seen bits and pieces and the cable run and it a thick yellow cord. I'll open the panel and look behind it.

thanks!

[Destiny_4588]

Did this on 4588. BUT we did a NEW AC MASTER PANEL. You will be spliting the 250/50A into to 125v/50A legs. Each leg is 50A. the key is balance the load on the two banks. (we did 3 banks -one for inverter loads and other two Shore/GenSet only loads.

The smartplug does not change the internal wiring which is where have to balance the loads. What is the out put of your gen set? Some are 250V which makes this very easy if that 125v then you have brigde the two banks when I gen set and separate when on SHore which can be hard to do on the factory panels.

Attached are few pictures of the panel we had made by Common Ground in Newport Beach, CA

To answer the question on fire concerns, you have to have the right size wire, correct sized breakers, and balanced banks to avoid issues. Most our boats have undersized wire for the loads we put on them today (ie a salon have 3 or four outlets, plug in space heater or fan, 40 TV, playstation, laptops, phone charges, power tool charges, ect and you quickly pass the 10 amp or 15amp breaker for this circuit can support (do not upsize the breaker without up sizing the wire runs.) Just sharing....undersized wire and bad connections cause the fires.


Attached files

[The_Other_Gary]

My 3988 was originally 2 x 50/125 inlts which the PO downgraded to 2 x 30/125 probably because the 30 amp were more available.

He left all the panel breakers at 50 amp and the inlet wiring at the original 6ga.

I replaced one of the (now) 30 amp inlets with a 50/125/250 inlet.

All the wires went into the inlet (red, black and green) but I had to put a small waterproof junction box in to tie the two neutrals into a single white neutral

so there would not be a rats nest or problem stuffing two 6 ga. wires into a run designed for a single 6 ga.

I also made up an adapter to split the 50/125 250 to 3 x 30 amp for those times when I got somewhere that did not offer 50/125/250 outlets.

this works fine as there is no 240 volt accessories on my boat and I could not see the value of buying a smart Y when there was no need for one.

The extra 30 amp inlet is still in place for cosmetic purposes only.

If your 3888 has 50 amp main breakers in the panel and 6 ga. wire from the inlet to the breakers the above solution will work for you.

The breaker amperage will be labeled on the breaker so you will have to look at the rear of the panel to check breaker size and wire sizes

[Cool_Beans]

Ok, I popped the panel and I do have 50 amp 125v breakers on the panel. The wiring looks nearly new to me, ie. in good condition.

Does it matter what the generator is? I have no idea to be honest. Gen and shore power go to a selector switch to go from one to the other. The genset feeds both banks when running and the selector switch set to "ship". I'm not following you Destiny, and not sure it applies to my boat. I don't want to mess with anything in the boat that can currently handle 50 amps. And I don't think the panel would know the difference between 2 shore power chords with 1 hot wire each feeding each bank vs 1 cord with 2 hot wires (1 feeding each bank)? Looking under my panel there are factory tags for "line 1 hot" and "line 2 hot". Under the window ledge there are 2 yellow shore power style cables that have 8/3 stamped into the them. I basically want to know, is it as easy as splicing these 2 cables together at the back of a new 50/250v inlet so I can go to one cord?

Right now I have 7 connections and 2 30 amp chords supplying 50 amp breakers and I do not want to go into winter like this. I like the Smart Plug design and the idea of a single cord.

Thanks!








Attached files

[The_Other_Gary]

I see you have the right breakers.

I recommend the following.

New 50/125/250 power cord and inlet.

Install this in line 1

remove all the 8 ga wires from your panel to the inlet and replace with 6 ga using proper crimp connectors and shrinks just the same as you have now.

THE MOST IMPORTANT one is the white neutral wire which must be upsized to 6 ga from the neutral buss to the new inlet.

and the Green ground wire must also ne upsized to 6ga.

Don't cheap out by buying RV cord, their 50 amp cords are 6 ga but the green grounding wire is often 8 ga. Don't ask me why but RV code is a little less strigent than marine code.

[Norton_Rider]

I see no mention of a galvanic isolator. If the boat currently has 30A galvanic isolators, it needs a 50A isolator installed. Better yet would be an isolation transformer, but that's more expensive.

[The_Other_Gary]

My 3988 came equipped with 50 amp galvanic isolators with the twin 50 amp service. Not sure if the 3888 was similarly equipped.

[Cool_Beans]

There is a 100 amp Zinc Saver on the ground wire?





Attached files

[Norton_Rider]

"Cool Beans" post=821187 wrote:
There is a 100 amp Zinc Saver on the ground wire?

That should work. You may need to upsize the wiring on it.

[Cool_Beans]

Awesome! This is looking to be easier than I thought. The hardest part is probably going to be getting the old cables out from under the window ledge and behind the wet bar.

Ok, so it looks like now the shore power L-1 and L-2 HOT (black) go to the source selector switch as do L-1 and L-2 NEUTRAL. New 6ga Red and Black L-1 and L-2 will go to the respective terminals, but I assume I need to jump the NEUTRAL terminals together on the switch before sending a new 6ga NEUTRAL back to the inlet?

Thanks!

[Destiny_4588]

Yes...neutral is neutral, ground is ground. You need to jump neutral.

Make sure your grounds are on the correct side of the zinc saver there is an in and out.