Dockside power issue

[steve c]

I have been at the same marina for 30 years and in the same slip for fifteen years with no dockside ac issues. This year the marina installed new floating docks, water and power. My boat trips the gfi at the dock. Since there is no 50 amp recepta
cle I use a splitter. The marina claims that new electrical codes cause many boats to cause this problem
because the codes used when the boat was built different codes were in play. Their solution...my boat,
my problem. They sent an electrician ( marine ) who changed a ground in the dc box on the bulkhead
in the engine room and said a splitter would not work on the marina's system. $315 later he says there
might still be a problem since he can't test it until a 50 amp receptacle is installed on the dock.
Anyone else have experience with this?

 

[RonNP]

With a splitter are you using two 30 amp outlets to plug into? Anytime I try to use a 30 amp outlet even with a smart Y I end up tripping the stump breakers. These old girls like their power.

 

[steve c]

The splitter has worked fine at this slip for the last 9 years.

 

[SKYCHENEY]

1) Do you have an isolation transformer? If so, your boat is not the problem. It can't be because you don't even bring the neutral on board your boat.

2) I have been to a marina with a similar setup for part of a year and when I tried to use the smart Y it tripped their system. I ended up building my own reverse Y without the brain box and it worked just fine.

 

[SEVEN]

Are you plugged into 2 30 amp plugs? If not you’re only bringing in limited power. Is your splitter a 50/125 or a 50/125/250?

 

[steve c]

2 30 amp cords to 30 amp dockside connected to a 50 amp splitter. Same
boat and hookups for 9 years. Only difference is new service at the dock. The marina
claims new codes require a change at the boat. Dozens of boats at the marina are having
similar issues. The claim is that new electrical codes are causing the problem with many
of the boats.

 

[steve c]

Sky: how did you put together the splitter w/o the brain ?

 

[SEVEN]

Sky: how did you put together the splitter w/o the brain ?

I’m interested in hearing about that. Those damn things are so expensive. I’d like to make a spare.

 

[SKYCHENEY]

Ok, against my better judgement, here goes. First, a safety warning: This does not contain the safety features of a smart Y. You need to plug each 30a into hots that are out of phase from each other. You will need to test the plugs at the pedestal with a mulitmeter to make sure you can get 250v out of the combination. If you don't understand electricity, please don't attempt this.

So, I cut off an old 50a/250 cord female plug end and two old 30a/125v cords male plug ends and combined them in a waterproof 4x4 plastic box with watertight cord grips. The neutrals were not used because I don't need them as I have an isolation transformer. One hot from each 30a cord was connected to each hot on the 50a cord. And the grounds were all tied together.

 

[Dazed338]

Is it only when attached to the boat that there is an issue? If it's just when the 2 feeds are attached to the splitter, without the boat attached. My thought would be Hot and Neutral and or Ground might be wrong in one outlet just a thought.

 

[SKYCHENEY]

Is it only when attached to the boat that there is an issue? If it's just when the 2 feeds are attached to the splitter, without the boat attached. My thought would be Hot and Neutral and or Ground might be wrong in one outlet just a thought.

Good point. Does the smart Y trip the GFI without having it connected to the boat? This should tell you if its just the Smart Y.

Also, if you don't have an isolation transformer, the problem could still be on your boat. Even a simple appliance can cause the fault like a micowave or refrigerator. Also a miswired plug. But if you are "isolated" then those won't matter.

 

[Walter P]

I had the same issue with my 1982 Series 1 48 MY. My slip did not have a 50A, 250 outlet so I bought
a "smart splitter " . Don't remember the cost but it was not cheap. Worked fine so I bought a second
one as "insurance" and to have on the boat for when I traveled since I did not like to take in the dockside
50A power cord. It was a PITA and heavy. A few years ago we had new power posts installed at my
slip with a 50A 250 outlet.....problem arose.... Our marina has 208V coming in and my incoming power
was just over 200V. I bought a power booster transformer and it brought it up fine. I still have some
splitters hanging around including the 2nd "smart" splitter as well as others from when I sold the boat. I
didn't seem to have the low voltage issue in other marinas. If anyone needs any of this stuff, please
call me and we can discuss it. At 82 I don't plan on buying another boat unless modern medicine can
make me young again so I want to just clear out all my inventory of spare stuff.

Walt
cell 732-991-5665
email waltpereira@aol.com

 

[carolinacoast]

I second Walt's point. Verify the voltage and amps of the new dock system. Some marinas go cheap, and do not run 277/480 volt power to the step downs.

 

[tonytrakovich]

Here is an interesting article on this. https://www.powerandmotoryacht.com/maintenance/why-some-boaters-suddenly-cant-connect-to-shore-power

 

[Pascal]

The most common cause is N to G bonding in appliances, typically non marine aplliances like fridge, stove, washer dryer. On boats the N to G bonding is supposed to be done at the power source whether shore, genset or inverter.

When using rotary switches for generators, there shouldn’t be an issue since the N gets disconnected by the rotary. When using breakers with safety slides it should fine too as long as the it s using three poles breakers that disconnect the N too

Inverters also bond N and G but marine inverters only do it when the inverter is on. If you have a non marine inverter you will have a problem

Our marina is supposed to be rebuilt in the next year or so and I ve been wondering about this issue. Since I be redone the whole electrical I know I don’t have any N to G bonding except in some of the appliances. I wonder if new aplliances still bond N to G

 

[Bob Bradley]

Have you tried plugging it into a neighbor's outlet to be sure that it is not just a problem isolated to yours?

 

[steve c]

As I said previously, same slip,cords and equipment on the boat. No new owner additions or changes.
No problem until new power at the marina which was installed under new codes that came into play
in 2018. I tried various power posts and varied connections to address phasing issues. It seems the
the new system is much more sensitive to electrical imbalances. A significant number of vessels at
the marina are having similar issues. A questioin for Sky: is the isolation device standard on a Hatteras
or is it an optional add-on?

 

[SKYCHENEY]

As I said previously, same slip,cords and equipment on the boat. No new owner additions or changes.
No problem until new power at the marina which was installed under new codes that came into play
in 2018. I tried various power posts and varied connections to address phasing issues. It seems the
the new system is much more sensitive to electrical imbalances. A significant number of vessels at
the marina are having similar issues. A questioin for Sky: is the isolation device standard on a Hatteras
or is it an optional add-on?

It was standard on most of the boats over 50' after about 1975 or so. The smaller boats just got the polarization transformers that only correct reverse polarity and don't isolate. Check your wiring schematics. It will show on the sheet that has the inlets and switches for powering the ships services. If you have an isolation transformer, it will be in engine room. Its a big gray metal transformer box about 18x12x8" and it will be warm if you are plugged in.

 

[Geoff58y]

We had a similar problem, equally frustrating, when our docks were rebuilt. First we found out that the new code for ground faults were at a higher spec and then (the source of our and our neighbors problem) was the neutrals at the inverter. Verify that all your neutrals are isolated. Ours werent and once fixed, the shore power issue went away.

also as a side note, to get a smart Y to work, the shore plugs have to wired out of phase.

 

[Pascal]

We had a similar problem, equally frustrating, when our docks were rebuilt. First we found out that the new code for ground faults were at a higher spec and then (the source of our and our neighbors problem) was the neutrals at the inverter. Verify that all your neutrals are isolated. Ours werent and once fixed, the shore power issue went away.

also as a side note, to get a smart Y to work, the shore plugs have to wired out of phase.

Was your inverter a marine inverter or a regular off the grid land model? Marine inverter only bond G to N when actually inverting.

As to the smart Y, that s the point. They will only kick in when the Hots are on opposing phases