[Fuzzdr]

I have a new-to-me Tiara 4000 Express 1997. The owner at my marina is blaming my boat/power cord for an electrical problem when my large cord is attached to his 50 amp receptacle. When that cord is attached, I have 240vac supply to my boat but no 120vac supply at all.
Using my voltmeter at his female receptacle, as expected both L1 and L2 are hot continuously. But the white neutral conductor cavity shows no continuity to the neutral bus in his power panel.....which is what I expected all things considered. Not sure if his ground is properly functioning or not. There are no breakers to be seen anywhere in the area for emergency shutoff. I have installed several 400 amp services in residences and small to medium sized businesses. I feel confident in my understanding of basic wiring principals and procedures. I am trained to be a medical doctor not an electrician however. Further on the way to this marina, I stopped overnight at no less than 5 other marinas. When plugged into 50 amp shore power there, I enjoyed full power for both 240 and 120 volts.

I am writing to find out about getting my power from 2 30 amp receptacles rather that the single 50 amp one. The nearest pedestal to me has +120 hot on one receptacle and -120 hot on the adjacent receptacle. ie; 240 vac across the pair. And 120 vac when either L1 or L2 is tested with the white neutral wire. So it seems that I should have everything to provide full power to my boat. My boat has a pair of 30 amp receptacles in addition to the 50 amp retracting cord. What I don't know is how my Tiara handles the power entering through my pair of 30 amp receptacles. I need to be sure I have 240 vac to run AC and battery chargers. Will I need to use a Reverse Y Connector?
Fuzzdr

[egstasea]

I have a new-to-me Tiara 4000 Express 1997. The owner at my marina is blaming my boat/power cord for an electrical problem when my large cord is attached to his 50 amp receptacle. When that cord is attached, I have 240vac supply to my boat but no 120vac supply at all.
Using my voltmeter at his female receptacle, as expected both L1 and L2 are hot continuously. But the white neutral conductor cavity shows no continuity to the neutral bus in his power panel.....which is what I expected all things considered. Not sure if his ground is properly functioning or not. There are no breakers to be seen anywhere in the area for emergency shutoff. I have installed several 400 amp services in residences and small to medium sized businesses. I feel confident in my understanding of basic wiring principals and procedures. I am trained to be a medical doctor not an electrician however. Further on the way to this marina, I stopped overnight at no less than 5 other marinas. When plugged into 50 amp shore power there, I enjoyed full power for both 240 and 120 volts.

I am writing to find out about getting my power from 2 30 amp receptacles rather that the single 50 amp one. The nearest pedestal to me has +120 hot on one receptacle and -120 hot on the adjacent receptacle. ie; 240 vac across the pair. And 120 vac when either L1 or L2 is tested with the white neutral wire. So it seems that I should have everything to provide full power to my boat. My boat has a pair of 30 amp receptacles in addition to the 50 amp retracting cord. What I don't know is how my Tiara handles the power entering through my pair of 30 amp receptacles. I need to be sure I have 240 vac to run AC and battery chargers. Will I need to use a Reverse Y Connector?
Fuzzdr

I have the 2002 version of the  4000 Express, and I am an Electrical Engineer.  The 50 amp receptacle at your marina most likely  has a loose neutral connection somewhere. 

You have three options:

1. get them to fix the loose neutral. 
2. use (2) 30 amp cords to your (2) receptacles.  (Mine only has one 30 amp 125v and one 50 amp 125/250v) 
3. get a smart reverse y splitter (like Hubbell YQ230) and plug the two 30 amp male end to the dock and the 50 amp end to the retracting cord.  I would get one of these no matter what, because you are bound to run into marinas with 30 amp only.  The smart splitter makes sure you are connected to L1 qnd L2 to get 250 volts.

[jclark003]

Are you sure your AC and charger are setup as 240? My 43 open also has a single 50 240VAC and a Single 30/120 and the generator wired in as 240. However nothing on my boats ac side is wired in at 240V. I believe there are 2 sides to the distribution panel that are each powered by one of the 240 legs (50a and generator). In the case of power coming in from the 30a connections, both sides of the panel are tied together at the source selector switch.

I suspect your 40 express is setup similar in which case 2 30A cords plugged into the 2 receptacles should power everything. I would give that a try before messing around with splitters. Let us know how you make out. I would be interested to learn if you actually have 240V appliances in your 40 express.

[Fuzzdr]

Thank you electrical engineer egstasea for your valuable professional opinions. I much appreciate your input. My marina owner seems to want to continue to blame my 50 amp cord and to not address the proven real issue of no effective neutral conductor in his 50 amp shore power setup. He has agreed to move on to me switching to a pair of suitable 30 amp supplies that contain both L1 and L2 respectively. We will see.......
Jclark003 thank you for your thread. I believe that 240 vac is needed on my boat to run my electric stove, my 2 ACs and my 2 battery chargers. They all do run under the present conditions of having 240 but no 120 volt power available. Fuzzdr

[Fuzzdr]

Re; loose neutral in the 50 amp receptacle- another voltmeter check revealed an ultra short flashing of 120vac, but nothing strong or sustained. To me this points to a loose neutral connection. On my initial voltmeter check days ago, there was not any trace of a neutral.
My next move was to hook a Marinco Reverse Y Connector to 2 dockside 30 amp receptacles (containing both L1 and L2). The result was the same; 240 vac into the boat but no 120 at all which surprised me??
My next  plan was to hook the 2 30 amp lines directly to the 2 30 amp receptacles on my boat. But wait, when I lifted the cap on one of these, there was no 30 amp inlet- only a female port for coaxial cable and obviously audio/video  and some other small port that I did not recognize. So I did the only thing left- ie; connect a single 30 amp line to my single 30 amp receptacle. Now I had 120 vac which ran my Acs and battery chargers (which seem to run on either 120 or 240 volts depending on what is available. But no power to my refrigerator, freezer or outlets. As for the outlets, I may have a GFI problem. No breakers are off so I am not sure about the lack of 120 volts.
Does anyone know why my Reverse Y Connector is providing 240 but no 120 vac??
From the beginning, the marina owner has insisted the lack of 120 when plugged into his 50 amp box is due to my big cord connector being defective. It has a little black tape on it which is not pretty but this has not stopped it from working perfectly at many other marinas. For no good logical reason other than the fact that I do own a brand new replacement plug, I did replace the 50 amp boat side plug. Everything was good inside the old plug as I knew it would be so now the new one is installed. No change, no 120 from that 50 amp shorepower box. Guess what the guy has a loose neutral somewhere in his line.  Fuzzdr

[egstasea]

[quote="Fuzzdr" pid='10455' dateline='1531049228']
Re; loose neutral in the 50 amp receptacle- another voltmeter check revealed an ultra short flashing of 120vac, but nothing strong or sustained. To me this points to a loose neutral connection. On my initial voltmeter check days ago, there was not any trace of a neutral.
My next move was to hook a Marinco Reverse Y Connector to 2 dockside 30 amp receptacles (containing both L1 and L2). The result was the same; 240 vac into the boat but no 120 at all which surprised me??
My next  plan was to hook the 2 30 amp lines directly to the 2 30 amp receptacles on my boat. But wait, when I lifted the cap on one of these, there was no 30 amp inlet- only a female port for coaxial cable and obviously audio/video  and some other small port that I did not recognize. So I did the only thing left- ie; connect a single 30 amp line to my single 30 amp receptacle. Now I had 120 vac which ran my Acs and battery chargers (which seem to run on either 120 or 240 volts depending on what is available. But no power to my refrigerator, freezer or outlets. As for the outlets, I may have a GFI problem. No breakers are off so I am not sure about the lack of 120 volts.
Does anyone know why my Reverse Y Connector is providing 240 but no 120 vac??
From the beginning, the marina owner has insisted the lack of 120 when plugged into his 50 amp box is due to my big cord connector being defective. It has a little black tape on it which is not pretty but this has not stopped it from working perfectly at many other marinas. For no good logical reason other than the fact that I do own a brand new replacement plug, I did replace the 50 amp boat side plug. Everything was good inside the old plug as I knew it would be so now the new one is installed. No change, no 120 from that 50 amp shorepower box. Guess what the guy has a loose neutral somewhere in his line.  Fuzzdr


So you really do only have one 30 amp connection on your boat like mine.  All of the loads on my boat are 120 volt.  When there is only one 30 amp circuit available I have to manage my loads.  When there are two available, I use a reverse y smart splitter an the 50 amp cable  ( I do not have the glendenning retractable)  When there is a 50 amp 125/250 volt available I use that.

Prove to yourself that you have continuity on your 50 amp cord.  Reel it out and take the male end down to the panel.  our should be able to ring out all the wire behind the panel.


One more thing, when you say you have 240 volts but not 120, do you mean on the meter? It will say 240 when you are plugged into the 50 or on generator, it will say 120 when plugged into 30 amp.

As to what you are seeing when plugged into the 30 amp: I believe that when plugged in 30 amp, L1 and L2 are paralleled on the boat. The fact that half your load work o your boat lead me to believe that you have a bad neutral connection on one side of the panel.  the confusing thing is that you said the boat works in other marinas.

Make sure the marina plug in actually 50 amp 125/250v. There is such a thing as a 50 amp 250v, the plug is slightly different but will fit if you force it.

[jclark003]

Egstasea has it right and this is what I was trying to say before. all of the ac systems on your boat should be 120 vac. The 50A 240v supplies 2 legs of 120 that supply different parts of your distribution panel / electrical load. Your single 30 is bridged across both sides and should supply the entire panel (at reduced capacity). The meter is just telling you what is being supplied.

If you are in doubt reach out to Tiara and they will most likely send you a electrical schematic.

If you are very comfortable around ac you may want to meter the back of the panel. With the 50 cord attached you should see 2 120 v legs (providing the neutral is present). if you don't then work backwards to the pedestal. If you do have both legs then work your way out to the breakers. Obviously be careful in there.

If you are convinced it is the problem you should be able to verify neutral at the pedestal. One lead into l1 and one lead into neutral should show 120. If it shows 120 the neutral is good if not then you have your proof to the marina operator that something is wrong.

[nukey99]

I have a 1994 4000 express, and it for certain takes the 50 amp 240 input and splits it into two 120 volt legs. I have a single 30 amp connector as well, but have never connected it, so I don't know how it is wired and what will work. I have checked each of my AC's and all are specified as 120 volt and replaced my water heater with a 120 volt unit (trust me, that is a job you really don't want to take on).

Given the problems you seem to be having at the marina power, I would recommend adding a galvanic isolator if your boat does not have one. My boat was burning through zincs, and I had my mechanic who is a graduate of Merchant marina academy with an engineering degree, perform a galvanic survey. The boat checked out clean, all bonding system correctly integrated. He then did a final check on the power post and found .05 volts being back fed into the boat on the ground wire. That was the source of the problem. We added an isolator and my zinc consumption returned to normal.

[ReelMagic]

You are correct your 50amp 240 volt cable is split into 2-circuits at the main electrical panel, each circuit capable of providing 120 volts @ approximately 30 amps... You also have a single 30 amp 120 volt circuit and when used powers both circuits but you are now limited to a total of 30 amp draw. When using the single 30 amp that is bridged you must limit yourself to drawing no more than 30 amps total or the main breaker will pop. On my 38 Open the main breaker for the 30 amp service is located outside in the cockpit near the connection for the dockside cable. M2C