Shore power newbie question

[diver dave]

I should add this risk to the equation. If you are sinking any neutral current, there is no guarantee that the current 50/50 splits down both white wires equally when using a Y, smart or not. You could have a situation, not unlikely, that 75% go down one and 25% down the other depending on all the half worn out contacts in this equation, and there are several.

 

[H3-40]

2 30s in phase won’t operate 240V loads, but it won’t hurt them either. I would rather have the power and manage the total current than do without. Just sayin’.

 

[diver dave]

2 30s in phase won’t operate 240V loads, but it won’t hurt them either. I would rather have the power and manage the total current than do without. Just sayin’.

Agree also. If you do have a 240v oven, a/c, dryer or the like and both legs in phase, you may find the lights and even controls may work but nothing behind the scenes work. Motors, heat all off.

 

[caltexflanc]

A Smart Y will not pass current if the legs are out of phase.

 

[ranger58sb]

I too have a 50A cord on board but i don't do a lot of brain damage when i come to a marina with 30A, nor do i mess with a reverse-Y. I just use a simple 50 to 30A adaptor cord, and I don't run my dryer or in winter, i dont run all my heaters at the same time./QUOTE]


I've been told 50A boats with isolation transformers won't do anything with AC from a 30-to-50A adapter. We don't have one, so the simple adapter approach works for us, at least enough to run minimal systems. Do you have an isolation transformer?

-Chris

 

[ranger58sb]

Not familiar with the expensive “reverse Y” adaptor, but from what has been described here it sounds like it will only permit power to flow if the two 30A outlets are on opposite legs. I fail to see the advantage of that.

2 30s in phase won’t operate 240V loads...

I think the two most commonly cited are about shock protection during the plug-in operation (no current flowing until both are connected), and expectation management (No 208V or better? Don't bother trying to run 240V stuff, if you have any. Do without, or move the boat, change slips, change marinas, whatever...).

-Chris

 

[caltexflanc]

I too have a 50A cord on board but i don't do a lot of brain damage when i come to a marina with 30A, nor do i mess with a reverse-Y. I just use a simple 50 to 30A adaptor cord, and I don't run my dryer or in winter, i dont run all my heaters at the same time./QUOTE]


I've been told 50A boats with isolation transformers won't do anything with AC from a 30-to-50A adapter. We don't have one, so the simple adapter approach works for us, at least enough to run minimal systems. Do you have an isolation transformer?

-Chris

30 or 50 amps of what? 125 or 240? We had isotranformers on the Hatt and it worked great with a Smart Y Never tried plugging a single 30amp 125 into it, though I know some Hatts had that as an option, a separate 30/120 inlet.

 

[Hamrow]

I too have a 50A cord on board but i don't do a lot of brain damage when i come to a marina with 30A, nor do i mess with a reverse-Y. I just use a simple 50 to 30A adaptor cord, and I don't run my dryer or in winter, i dont run all my heaters at the same time./QUOTE]


I've been told 50A boats with isolation transformers won't do anything with AC from a 30-to-50A adapter. We don't have one, so the simple adapter approach works for us, at least enough to run minimal systems. Do you have an isolation transformer?

-Chris

Chris, no we do not have an isolation transformer, our power just goes through a Magnum pure sine inverter.
I haven't yet identified a need for the IT, but if we do the loop where you're exposed to so many different kinds of marina power environments, I might find it would be handy to add one.

 

[ranger58sb]

30 or 50 amps of what? 125 or 240? We had isotranformers on the Hatt and it worked great with a Smart Y Never tried plugging a single 30amp 125 into it, though I know some Hatts had that as an option, a separate 30/120 inlet.

Yeah, sorry, I meant 50/240... and that I've been told an isolation transformer in that kind of install won't work when only supplied with via a 30-to-50/250 adapter.

Came up when members in our owners club were working out how to charge new-to-them boat batteries while on the hard with only household power available in the back lot. Some of the guys with newer boats and isolation transformers said they weren't able to make it work with simple adapters...

Whereas for us, one time several years ago, no transformer, it was easy. 15A-to-30A plug, 30-to-50/250 pigtail, E Voila!

-Chris


-Chris