Shore Power Setup

[rich2925]

Hello

So we stayed on the boat this weekend and decided for the first time to use the reverse cycle air con as heating, this worked really well and the boat was very cosy.

Anyway the only way I can see to run this is by connecting Shore power to both of my shore power connectors 1 x32amp 1 x 16amp

From what I can see the 16amp is only there for the Air con but I was wondering if there is a way to run all of this on 1 lead.

I don't know what load is on the 32amp circuit or how much the aircon requires but wondered if the zircon could be connected to a socket in the boat running of the 32 amp circuit.

Any ideas would be appreciated and when I get the best solution wondering where to buy some new shore power cables that look a bit nicer than my current tatty ones.

Thanks

Richard

 

[MapisM]

From what I can see the 16amp is only there for the Air con but I was wondering if there is a way to run all of this on 1 lead.

Well, that depends on how the cabling is arranged, and on the current absorption.
But in principle, I'm a bit surprise to hear that a Targa 38 (if that's the boat you are referring to) has two shore power connectors, for 48A overall.
I mean, my 56 f/b has a two compressors 36kBTU a/c system, cooktop, dishwasher, washing machine, oven, 100A battery charger, etc., but shore power goes through a single 32A socket, and I never had any problems.
Sure, we never ran all the appliances together with full power a/c at the same time, but you can see why I would expect a single 32A connection to be more than enough to handle a T38...

 

[jimmy_the_builder]

Isn't this a case for an LBOK?

 

[Seastoke]

Hello

So we stayed on the boat this weekend and decided for the first time to use the reverse cycle air con as heating, this worked really well and the boat was very cosy.

Anyway the only way I can see to run this is by connecting Shore power to both of my shore power connectors 1 x32amp 1 x 16amp

From what I can see the 16amp is only there for the Air con but I was wondering if there is a way to run all of this on 1 lead.

I don't know what load is on the 32amp circuit or how much the aircon requires but wondered if the zircon could be connected to a socket in the boat running of the 32 amp circuit.

Any ideas would be appreciated and when I get the best solution wondering where to buy some new shore power cables that look a bit nicer than my current tatty ones.

Thanks

Richard

What you must not do is join the two inputs together without change over switch,have a look in the manual to see what load ,the air con takes ,you could buy a clip on amp meter and measure the load on your 32 amp supply ,it would also measure the air con load ,obviously with all things switched on,ie do u cook electric do you have water maker etc

 

[jimmy_the_builder]

Isn't this a case for an LBOK?

Oh wait, I've got this the wrong way round - the LBOK is where you need two connections on shore to provide enough power for a single inlet on the boat.

Doesn't the OP just need a simple (home made) Y-cable?

 

[Seastoke]

Oh wait, I've got this the wrong way round - the LBOK is where you need two connections on shore to provide enough power for a single inlet on the boat.

Doesn't the OP just need a simple (home made) Y-cable?

Well Jim if he did that and there was say a problem ie insurance ,they could say that a 16amp socketshould not be protected by a 32amp supply

 

[superheat6k]

Connecting to two shore power outlet receptacles to a single on board power supply is definitely NOT a good idea. This applies if you make a Darwin Award winning dual connection lead - two males to one female, or simply use two normal but separate leads connecting on board to the same electrical system Live & Neutral.

Indeed if there are two on board sockets these should have a switch so only one or the other can be selected at any one time.

Please consider ...

1 Risk of live prongs on one or other of the shore power male connectors. The consequence of touching one of these would be potentially fatal.

2 Also a severe risk to swimmers / fallers in should one of these fall in to the water.

3 Risk of blowing your hand off or worse if you plug in the second of these to an opposing phase - 400 Volts direct phase to phase short circuit will cause an immediate explosion in your hand as you insert the second plug. Not all shore receptacles will be on the same phase, and without a meter to check there is no way of knowing.


The only thing you could consider would be having completely separate 240v on board systems - one 16a fed and the other 32a fed, but it must not be possible to cross connect these by any switching arrangement, or you will compromise the above.

 

[MapisM]

Connecting to two shore power outlet receptacles to a single on board power supply is definitely NOT a good idea.

Yup, that's understood.
In fact, it wasn't christened Lethal Bit Of Kit for nothing! All debated years ago in this thread…
Otoh, if we should refrain from putting in practice any idea which is not good, we wouldn't have several bikers here in the asylum, would we?

 

[MapisM]

Doesn't the OP just need a simple (home made) Y-cable?

Actually, the non-lethal version p), i.e. one male and two females, is also commercially available - no need to build it.

Btw, I think that the objection from seastoke is only correct in theory, because in a properly built boat, the 16A line should be protected by a 16A breaker also internally, so the fact that the 32A breaker on the dockside would not trip off when drawing more than 16A doesn't really matter, because it's the onboard breaker that would - or am I missing something?

 

[jimmy_the_builder]

Connecting to two shore power outlet receptacles to a single on board power supply is definitely NOT a good idea. This applies if you make a Darwin Award winning dual connection lead - two males to one female, or simply use two normal but separate leads connecting on board to the same electrical system Live & Neutral.

Indeed if there are two on board sockets these should have a switch so only one or the other can be selected at any one time.

Please consider ...

1 Risk of live prongs on one or other of the shore power male connectors. The consequence of touching one of these would be potentially fatal.

2 Also a severe risk to swimmers / fallers in should one of these fall in to the water.

3 Risk of blowing your hand off or worse if you plug in the second of these to an opposing phase - 400 Volts direct phase to phase short circuit will cause an immediate explosion in your hand as you insert the second plug. Not all shore receptacles will be on the same phase, and without a meter to check there is no way of knowing.


The only thing you could consider would be having completely separate 240v on board systems - one 16a fed and the other 32a fed, but it must not be possible to cross connect these by any switching arrangement, or you will compromise the above.

Yep T all understood, cheers, I wasn't advocating, I was simply referencing previous (and repeated) discussions about shorepower connections of this nature. Mapism has v helpfully posted the relevant link (thanks P!).

 

[jimmy_the_builder]

Well Jim if he did that and there was say a problem ie insurance ,they could say that a 16amp socketshould not be protected by a 32amp supply

Roy I don't think you're right on this, with respect - what's the difference between doing this, or just plugging your 16A inlet into a regular 32A shorepower supply, with no Y-cable involved? I've done this a bunch of times in the Med, and even connected to a 64A supply. The crucial point is that the boat's 16A inlet doesn't rely on the shorepower breaker for protection - it has its own inlet breaker for primary protection.

 

[Portofino]

Roy I don't think you're right on this, with respect - what's the difference between doing this, or just plugging your 16A inlet into a regular 32A shorepower supply, with no Y-cable involved? I've done this a bunch of times in the Med, and even connected to a 64A supply. The crucial point is that the boat's 16A inlet doesn't rely on the shorepower breaker for protection - it has its own inlet breaker for primary protection.

Would the cable thickness of the 16 A be compromised in any way as you go to higher sockets ( with adapters ) ? I mean get a bit warm !

Aside back to the OP I see these twin set ups on Jeanneau boats and can,t think what the USP / advantage is .
I just see the down sides .
Lack of two sockets available ( full berths ) so they seem to have a Y buts it’s in one , could be the 32 or the 16 ,depends on the boat L .
Sometimes I see two 32 ,s going via two seperate lines of suitable thickness to two seperate IN females on the boat .
The 32 A is heavier thicker copper than the 16 A .

Meanwhile as MapisM says everybody else seems to manage with one ,sub 12 M generally 16 A , 50 ftrs one 32 A except Jeanneau,s .
We are 32 A single with a 42K BTU Aircon , electric galley , 80 amp charger + 20 amp secondary charger ,huge electric water heater , The Aircon has some hefty 220 Calpedi pumps , etc etc all from one shore plug .
There’s a few breakers on the AC section and with most on if you say try to boil a kettle it has been known to trip at the boat .The shorepower lead is pretty thick and heavy a bit too much for females arms ..

So maybe the USP of the twin is smaller lighter easier to manage shorepower cable ——- dunno ?
But surley if you rock up an an August BH in any marina either U.K. or Med you are only have one socket available??
Be it a 32 A If in 15 M berth or 16 A If in a Targa 38 berth .

Help me out someone - why two leads of diff A ??

 

[MapisM]

Would the cable thickness of the 16 A be compromised in any way as you go to higher sockets ( with adapters ) ? I mean get a bit warm !

I can't see why.
Assuming that there's a 16A breaker onboard, you will never have more than that flowing through the cable, even if the dockside is rated for 64A or whatever.
Which is what I said in my post #9, and JtB reiterated in #11.

Ref. your last Q, not a clue!

PS: your a/c raw water pump is actually "Calpeda" [/pedantic mode]

 

[Portofino]

I can't see why.
Assuming that there's a 16A breaker onboard, you will never have more than that flowing through the cable, even if the dockside is rated for 64A or whatever.
Which is what I said in my post #9, and JtB reiterated in #11.

Ref. your last Q, not a clue!

PS: your a/c raw water pump is actually "Calpeda" [/pedantic mode]

Thx for the spelling test results :encouragement: It won’t be the last time btw

At first pass I agree with the concept of the boat breaker is the gate keeper .

Was thinking if there’s a fault with the boat breaker and a greater Ampage from the shore box might end up flowing down the relative weedy 16 A dia lead from the more hefty supply be it a32 or worse 64 A .
In the boat the user would think great as everything was running + much more plugged in like winter oil heaters, kettles , hairdryers , etc without a trip from the boat .

So wouldn’t it be better for folks that are uncertain what the supply box A is gonna be when they arrive at a visiting berth ,up spec the lead dia to cope with what the box is capable of dishing out ?
You never know if an appliance or the breaker or both develops a fault .

Sudden surges stuff turned on simultaneously etc
The distribution AC panel after the duff breaker presumably spreads the Amps to the appliances ,but it’s all gotta come down through the shore power lead .

Just seems a accident waiting to happen when you see the relative lead dia of say a 64 to 16 or 32 to 16 adaptors.

I might be over thinking about his ?

 

[jimmy_the_builder]

I might be over thinking about his ?

You are . I can't speak for other boats, but my own Targa 40 has a main breaker at the shorepower inlet, and another one on the panel. So the situation you're chasing is (a) the inlet breaker fails (b) the panel breaker fails (c) there's some other fault on the boat that causes some huge jump in demand and (d) you happen to be connected to some massive capacity supply at the time. Vanishingly unlikely. But, to your point, if all of this did happen, I'd rather have a weedy shorepower cable and let the fault manifest there ie outside the boat, rather than overload the appropriately-rated wiring inside the boat. So - your 16A cable is fine...

 

[jrudge]

Read this and what the OP wants to do ( I think) is simple.

He has 2 shore power inlets.

16a and 32a.

One runs AC. This is REALLY useful as it lets him run his AC off a 16 a socket and the boat systems ( chargers etc) off another. I have 32/32 on mine and it is so nice knowing you aren to going to trip shore power with the AC running. Anyway I digress.

I assume his berth only gives him one 32a socket, so he wants to run both of them off the same supply.

I can see no issue here, it is simply a Y cable which personally I would put on the dock as opposed to dangling at the back of the boat.

So he has the long wires that he has now which one assumes are correctly rated for the current.

He then makes / buys a Y adaptor. 32a to 32 and 16. The connecting wires for each are rated at 16/32 ( if i was making it I would make both 32 as it is simpler to purchase one length).

there are no issues I know of.

The socket will supply 32 amps ( in practice I suspect it wont pop until past 40) and each circuit on the boat is protected by its own inlet breaker ( my fairline is ).

 

[MapisM]

Well, if it were my boat and I would have in mind to keep her, I'd rather access the inner side of those two inlets, detach the wires from the 16A socket attach them in parallel to the 32A.
This way, you can use just one 32A cable at all times, and call it a day.
In fact, unless I'm missing something, for all intent and purposes that's exactly the same as using two cables with a Y adapter on the dockside.

 

[MapisM]

I might be over thinking about his ?

You are

+1 :encouragement:

 

[petem]

Assuming the OP has a 32amp marina socket then surely all he needs to buy is:

1) 32amp shorepower splitter / 'Y'
2) 32amp -> 16amp converter cable

No need to make anything at all!

 

[petem]

+1 :encouragement:

Poor Porto would have a heart attack if he saw my 16amp shorepower to 13amp UK socket cable!

Worse still if I connected this using my 32amp to 16amp converter cable .