New Boat - all to get underwater lights!

[BartW]

Did you try if one of these does the trick?
Mind, I don't think you actually find it already built, 'cause you need it with male and female "reversed", compared to the pic. But building one is a 10' job.

this could / should work, but I would never want something like that on my boat,
firstly:
not every potential user is aware of what a 3 phase supply means,
f.e. Like in the yard in Rome, on my pole are 4 x 230V 16A sockets, and 3 phase supply !!! yes, indeed there are only two sockets that I can / must use with such a combiner,
if somebody else on the pontoon changes the plugs in another socket, "Bang"

secondly;
if only one of the male plugs is disconnected, the pins are free to touch, and directly 230V high current on them, deadly dangerous !

 

[MapisM]

I take your point, but find a cheaper solution if you can!
That aside, IIRC, in Croatian marinas 3 phase sockets are always different (the red ones), if and when available.
Actually, I'm surprised to hear that also at your yard they're using the same sockets for 3 phase.
What are you supposed to do, try them with a tester before using them?

 

[Deleted User YDKXO]

Did you try if one of these does the trick?
Mind, I don't think you actually find it already built, 'cause you need it with male and female "reversed", compared to the pic. But building one is a 10' job.

Yeah, got plenty of those on board but if you reversed the male/female connectors, you'd blow the shorepower instantly IMHO

 

[MapisM]

Why? Maybe you didn't see what I meant.
The connectors should be reversed only to use two supplies (if available of course), and connect both to one shorepower cable which goes onboard.

 

[Deleted User YDKXO]

16A is more then enough to heat or cool my 70ft boat.
if the startup current from the compressor motor is a problem, for that you can add a "soft start" to the electric motor

Firstly, I'm no expert on electrics but all I can say is that I'm generally very careful about how I connect up to a 16A shorepower supply. I will make sure that all the individual AC circuits (a/c, hot water, microwave, sockets etc) are switched off so there is no load when I first switch on to shorepower and then switch on each circuit individually. It is always the a/c circuit that blows a 16A shorepower supply, not usually instantly but after a couple of minutes operation when the compressor starts to kick in. Maybe its the high start up load required by the compressor, I don't know. Yes I'm sure that once the system is operating in a stable condition, it won't consume 16A but it's getting there that is the problem.
IMHO, there is also a voltage problem in some Med marinas too. I have seen voltages well below 200V in some marinas and I guess that if the voltage is low, the current consumption will be higher

 

[BartW]

I take your point, but find a cheaper solution if you can!
That aside, IIRC, in Croatian marinas 3 phase sockets are always different (the red ones), if and when available.
Actually, I'm surprised to hear that also at your yard they're using the same sockets for 3 phase.
What are you supposed to do, try them with a tester before using them?

on a 3 phase red socket you can't use this combiner !
you can use my and Jfm's split system on a red socket dough

a 3 phase supply can be split out in several monophase 230V Blue sockets,
If on the electric pole are only 3 blue sockets you can't use the combiner.
If there are 4, at least two of them are connected to the same phase,
on these you can use the combiner when the polarity in the two sockets is the same. (wires not twisted in one socket compared to the other)
On a monophase electric pole, you only have to check polarity.


This combiner can work if you know what you are doing,
and Deleted User clearly doesn't sorry Mike, I'm sure you have other things you're good at
measuring is the answer,
basically the voltage between the corresponding pins in the two blue sockets must be zero, while both have a hot 230V supply.
and in some circomstances this is possible.

 

[BartW]

Firstly, I'm no expert on electrics but all I can say is that I'm generally very careful about how I connect up to a 16A shorepower supply. I will make sure that all the individual AC circuits (a/c, hot water, microwave, sockets etc) are switched off so there is no load when I first switch on to shorepower and then switch on each circuit individually. It is always the a/c circuit that blows a 16A shorepower supply, not usually instantly but after a couple of minutes operation when the compressor starts to kick in. Maybe its the high start up load required by the compressor, I don't know. Yes I'm sure that once the system is operating in a stable condition, it won't consume 16A but it's getting there that is the problem.
IMHO, there is also a voltage problem in some Med marinas too. I have seen voltages well below 200V in some marinas and I guess that if the voltage is low, the current consumption will be higher

reading this, I'm almost convinced that you would do well with a seperate supply for the AC, and that one can alway's be in a 16A socket,
while the other supply line depends on what you're using simultaniously,
batt chargers, boiler, dishwasher, washing machine, galley, are the high loaders.

BA is now running on 2 x 16A supply's, we use the heating permanently,
and we do use the dishwasher, the water boiler, and many halogene lights !
but not all simultaniously.

 

[MapisM]

on a 3 phase red socket you can't use this combiner !
....

Oh yeah, I know.
My previous post was because I misunderstood your previous comment re. 230V sockets with 3 phase supply.
In fact, even if 3 phase 230V indeed exists, it did seem weird to have that in a boat yard...
Now I see what you mean.

Then again, in many marinas, inside the dock columns supplying only 230V you can find a main 230V line reaching a box, where for instance the 4 sockets are connected through 4 16A thermal switches.
In that case, the above splitter (or "combiner", as you called it more aptly) works nicely no matter to which of the 4 sockets you connect it.

 

[Deleted User YDKXO]

and Deleted User clearly doesn't sorry Mike, I'm sure you have other things you're good at

No offence taken According to my SWMBO, I'm good for nothing so I know my place

 

[henryf]

When racing at Silverstone they provide 3 phase (red) sockets in some areas to provide "shore power" to support vehicles. We bought a cheap red to 16 amp blue adapter to plug in our motorhome. Given it didn't catch alight and I wasn't fried in the process I presume taking a single phase tap off a 3 phase supply is quite simple. I am not suggesting a DIY guide for fear of losing valuable forum members but you don't need any fancy converter boxes.

A boat I am looking at is fitted with A/C and so has 2 16 amp shore power leads from the factory. I presume it is possible to buy a Red (3 phase) plug to 2 blue (16 amp) converter for use in marinas where such a supply exists.

It would save hogging the 16 amp hook up points.

Henry

 

[BartW]

Then again, in many marinas, inside the dock columns supplying only 230V you can find a main 230V line reaching a box, where for instance the 4 sockets are connected through 4 16A thermal switches.
In that case, the above splitter (or "combiner", as you called it more aptly) works nicely no matter to which of the 4 sockets you connect it.

as long as the polarity from the blue sockets is the same, and you will have never garanty for that.

 

[BartW]

A boat I am looking at is fitted with A/C and so has 2 16 amp shore power leads from the factory. I presume it is possible to buy a Red (3 phase) plug to 2 blue (16 amp) converter for use in marinas where such a supply exists.

exactly, (and easy to make)
you would even be better with a red 3 phase plug to 3 x blue 16A sockets
so you can please your neighbour when no more sockets available.

 

[MapisM]

you will have never garanty for that

Well, I agree that you can never trust a marina to do anything 100% correct, if that's what you imply...
But the polarity is a pretty basic thing, if they manage to invert the live and neutral wires even inside the same column sockets, I'm not sure I would trust the bow lines to keep the boat secured in any sort of breeze!

 

[MapisM]

I presume it is possible to buy a Red (3 phase) plug to 2 blue (16 amp) converter for use in marinas where such a supply exists.

It would save hogging the 16 amp hook up points.

All agreed, but you and Bart are not considering what Mike said:
The problem for me in Croatia is that 16A supplies are the norm and 32A is the exception, at least on the berths we get allocated.
Which pretty much fits what I recall of Croatian marinas.
If the dock is organised in such way that all you've got are 230V 16A sockets, I've yet to understand what else can be done, aside from what I suggested.

Otoh, I agree with the cautions Bart mentioned.
Particularly with the fact that if one of the two plugs get disconnected (frinstance by a neighbour who wants to connect his cable), there is an exposed hot plug.
Even the polarity thing is no big deal, if it would really be wrong between the two sockets, all can happen is that one of the two thermal switches trips.

 

[jfm]

Did you try if one of these does the trick?
Mind, I don't think you actually find it already built, 'cause you need it with male and female "reversed", compared to the pic. But building one is a 10' job.

Blimey MapisM. If you make that with the male/female reversed, you have a lethal bit of kit. With such a device, you can connect across two phases, 440v. You are aware of the significance of this aren't you? No-one should have such a bit of kit on their boat unless they fully understand 3-phase elctricity and of course no boat shop would be allowed to sell such a device (thankfully)

With a bit of luck, adjacent sockets on the same shorepower box will be connected to the same phase of the marina's 3phase supply. But if you made a longer device like that, and connected to two shorepower supplies on different shorepower boxes, they could easily be different phases off the marina's 3-phase supply.

 

[Deleted User YDKXO]

If the dock is organised in such way that all you've got are 230V 16A sockets, I've yet to understand what else can be done, aside from what I suggested.

In my case, switch on the generator and annoy the neighbours next door

 

[jfm]

That sounds more like an AC supply management system than an AC supply combining system. Yes you can feed 63A into circuit A or B from the shore supplies or gennies but you can't feed 2 x 63 = 126A into either circuit A or B. Say you had an AC appliance in circuit A which required 100A. Could the system on Match handle that?
The problem for me in Croatia is that 16A supplies are the norm and 32A is the exception, at least on the berths we get allocated. My aircon invariably blows a 16A circuit but works fine from a 32A supply. Is there any kind of equipment on the market which can combine 2 x 16A supplies to feed 32A into a single AC circuit? I don't see anything on the Victron or Mastervolt websites that does that

Agreed, and i never said it "combined". It has a similar practical effect to combining, by allowing you to run half the boat off one shore power supply and the other half of the boat of another shorepower supply, but there is no actual combining

I cannot imagine ever having a 100amp single phase appliance on a boat (can you think of one?) but yes my system could not run such a device off 2x 63A shorepower supplies. Actually each of my shorwpoer supplies is 100A and so if the dock would supply 100A to a single shorepower then I could run your 100A device, but that is totally academic becuase 100A single phase appliances generally do not exist

Getting back to your question, afaik there is no device on the market which can combine 2 x 16A supplies to feed 32A into a single AC circuit in a way that is "proofed" agianst the possiblitly that the two shorepower supplies are phased 120deg apart. If anyone knows of one, I'm very happy to be corrected. If you are sparky-knowledgeable and KNOW the two shorepower supplies are running off the same phase (look inside the box to see how it is wired, or measure the voltage across the two lives) than you can with caution use the Mapis device.

As BartW said, you can get soft start devices to eliminate the start up spike on your single phase a/c motors, and better still variable frequency drives that run 3-phase a/c motors off single phase supply. These are common on bigger a/c installs and are standard gear on 70 footers+ approx

 

[BartW]

With such a device, you can connect across two phases, 440v.

excuse for the pedantry Jfm,
but its 380V across two phases

 

[MapisM]

if you made a longer device like that, and connected to two shorepower supplies on different shorepower boxes, they could easily be different phases off the marina's 3-phase supply.

Agreed, I never suggested that.
It's also true that such "reversed" Y connector is not available anywhere, and I had to make it myself, in my Croatian days.
Otoh, I never made any damage with such lethal equipment...
...and never had to switch on the generator and annoy the neighbours next door
Actually, coming to think of it, once I even borrowed the lethal thing (I like that definition!) to a neighbour who seemed unable to live without A/C, in a day when I wouldn't have even thought of turning it on - hence I wasn't using it.

 

[jfm]

excuse for the pedantry Jfm,
but its 380V across two phases

Ah yes, it is indeed! sorry!