Confusion over 50-amp vs. 30-amp shore power

Status
Not open for further replies.
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
All,

I have done some searches and found some info but I still do not know if I understand this situation enough.

I am going to have to change slips at my marina. Current slip has 30-amp power and that is what I have been using for a year.

New slip has 50-amp power which uses a different type of connector.

I have a Y-Cord that looks like it will plug into the 50-amp shore power and leave me with a 30-amp plug to use with my 30-amp shore power cord going to the boat.

What I am most confused with I think is the 120 vs 250 volt situation. Is this an issue? Can I only use my Y-Cord adapter if the shore power is 50-amp/120-volt.

Or does the Y-cord take care of the voltage issue as well?

Thanks for any insights on this shore power issue.

Cheers,
Jim
 
Don S/V ILLusion

Don S/V ILLusion

.
Sep 25, 2008
7,099
Alden 50 Sarasota, Florida
Think of the splitter as nothing more than a plug adapter allowing you to use a 30amp plug on a 50amp plug. The voltage doesn't change nor does the current load.
 
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
So that means I need to ask the marina if that is 120 or 250 volts. And if it is 250 then I have a problem. But if it is 120 then I am good to go using the Y-cord adapter.

Don't really want to move. The power issue may force the harbor master to make an exception and let me stay where I am.

Jim
 
Don S/V ILLusion

Don S/V ILLusion

.
Sep 25, 2008
7,099
Alden 50 Sarasota, Florida
c130king said:
So that means I need to ask the marina if that is 120 or 250 volts. And if it is 250 then I have a problem. But if it is 120 then I am good to go using the Y-cord adapter.

Don't really want to move. The power issue may force the harbor master to make an exception and let me stay where I am.

Jim
Click to expand
Definitely ask but the plugs are conventionally different, I.e., a 120v plug regardless of it being on the y-adapter, typically will not mate to a 220v plug as they typically have different pin cofigurations. The 240 v plug will have 2 hot pins.
 
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
Don,

If it is indeed 120 volt then I can use the 50-to-30 Amp Y-Cord with no other issues?

Thanks,
Jim
 
K

kbuckley

.
Jul 21, 2010
30
Dufour 365 Granville Isl. Vancouver
An electrician should be able to make an adapter for you even if the plug is 240v since 120v is still accessible on that plug. Or maybe they will swap out the outlet and breaker for you, or let your electrician swap them...

But as noted, provided you buy a 120v 50amp plug you won' t accidently end up with 240v on your boat.

Re: 50amp vs 30amp - your boat is still protected by its 30amp breaker but your power cord is not unless provision is made for a 30 amp breaker in the adapter.
 
Witzend

Witzend

.
Dec 25, 2008
1,580
catalina 310 Elk River
kbuckley said:
Re: 50amp vs 30amp - your boat is still protected by its 30amp breaker but your power cord is not unless provision is made for a 30 amp breaker in the adapter.
Click to expand

Nor is the receptacle and the wiring to the breaker on your boat.
 
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
Don't the Marinco Y-Cord adapters come with the appropriate fuse/breaker for this purpose?
 
Don S/V ILLusion

Don S/V ILLusion

.
Sep 25, 2008
7,099
Alden 50 Sarasota, Florida
c130king said:
Don,

If it is indeed 120 volt then I can use the 50-to-30 Amp Y-Cord with no other issues?

Thanks,
Jim
Click to expand
I do it all the time when transient docking. If your boat is properly "fused", you can't toast the boat wiring.
 
B

Barnacle Bill

.
Jun 9, 2008
1,771
- -- -Bayfield
For your boat you want a 30 amp connection. 50 amps is for big yachts with huge power consumption needs. You shouldn't need a splitter. If you have the proper 30a power inlet and your dock supply has a 30a outlet, then you 30 amp cord should be all that you need.
 
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
Billl,

My new slip has a 50-amp outlet. It is a different design and my 30-amp cord will not fit in this outlet.

But I have a Y-Cord Adapter that came with the boat. So if it is 120-volt 50-am power then I think I will be good to go by using this adapter.

If it is 240-volt then my understanding of this situation is that I won't be good to go and the harbor master will have to either let me stay where I am (which is what I hope happens) or change the power supply at that slip.

They are moving my 31' boat to a 64' long 30' wide slip. The slip is too big the dock is too high and the power is not what I need. It is a long story that I don't want to go into here. But I keep hoping that the harbor will change its mind and just let me stay where I am.

Cheers,
Jim
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,674
Canadian Sailcraft 36T Casco Bay, ME
You really need to ascertain what the dock pedestal receptacle is? Is it a 50A X 125V/250V service or 50A X 125V service. The plugs are totally different and are not interchangeable.

Some of these adapters get quite expensive so you need to know what you need. If you can tell us what your dock pedestal is and what your "Y" is for and we can help or at least steer you to the adapter you need.
 
c130king

c130king

.
Mar 22, 2009
360
Catalina 310 Gulfport Small Craft Harbor, MS
Good videos. Thanks Stu. My Y-Cord says 50-amp 125/250-volt on the plug end. And of course the two Y ends are 30-amp outlets.

So from that first video (of the three) my take was that this cord should allow me to be good to go if the power coming out of the pedastal is 250-volt...or am I still confused...
 
Status
Not open for further replies.

Top Bottom