30 AMP to 50 AMP Adapter

B

Brian77

Member
Oct 5, 2010
114
Long Island
Boat Info
370 Sundancer 1992
Engines
7.4 Mercruiser with V-Drives
Hey everyone,

I just found the following 30 amp to 50 amp adapter at Home Depot for $49:
http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10051&productId=202185142&langId=-1&catalogId=10053&ci_sku=202185142&ci_src=64119933&cm_mmc=shopping-_-googleads&locStoreNum=1218&marketID=20

Does anyone know if these are good/safe? It's less then half and in some cases a quarter the price of the adapters made by other manufacturers.

Oh, and in case you're wondering, the state park marinas around me only offer 50 amp service, so I'd like to purchase an adapter so I don't have to keep renting.

Thanks,

Brian
 
It looks good to me! It says it's marine rated and looks like my Marinco. I'd give it a try.
Todd
 
You're right - the zoom view is a 30A to 15A adapter, which makes more sense from a pricing standpoint, but the description clearly states 50A...
 
The problem is using 30 amp cable/plugs on 50 amp service. If a fault occurs, the 30 amp cable could melt down before the 50 amp breaker trips.
 
If its not the right one - I have one I used for one season for a similar reason - I paid $150 for it I'd sell it for $50
 
Over at Watch Hill, Part of the Fire Island National Seashore, they rent the same ones for $5.00 a day. There hasn't been any fires there yet. The adapter is allowing you to draw 30 amps from a 50 amp outlet. I could see the possibility of a problem if it was reversed because the outlet on the box could then overheat.
Todd
 
tdschafer said:
There hasn't been any fires there yet. The adapter is allowing you to draw 30 amps from a 50 amp outlet.Todd
Click to expand...

The adapter does not limit the current... the 50 amp breaker does. That said... it's no different than using a 16AWG extension cord in a 20 amp wall outlet. We all do it! :grin:
 
:smt038
JimG said:
The problem is using 30 amp cable/plugs on 50 amp service. If a fault occurs, the 30 amp cable could melt down before the 50 amp breaker trips.
Click to expand...

You sure about that? I don't think it works that way. I'll bet a beer that the 50A breaker will trip when that adapter starts to draw more than 25A....

edit: should have bet me that beer.....
 
Last edited:
Four Suns said:
You sure about that? I don't think it works that way. I'll bet a beer that the 50A breaker will trip when that adapter starts to draw more than 25A....
Click to expand...
So you think the adapter limits the current? :wow:

The 50A breaker limits the current regardless of what size cable is plugged into it. Try plugging an 18 gauge lamp cord into a 50A breaker, then short the end of it... see what blows first!

So how do I collect that beer?
 
JimG said:
So you think the adapter limits the current? :wow:

The 50A breaker limits the current regardless of what size cable is plugged into it. Try plugging an 18 gauge lamp cord into a 50A breaker, then short the end of it... see what blows first!

So how do I collect that beer?
Click to expand...

I say the 50 amp breaker blows up second, immediately after the guy shorting the end of the 18 gauge lamp cord!:smt024
 
I'm going to order it and I'll let everyone know how it looks.

Thanks,

Brian
 
I don't think the adapter limits the current. But I don't know how a two pole breaker trips. The adapter is just tying into one of the two hot wires... My question/comment is based on does the breaker trip if one leg exceeds 50A or if either leg exceeds 25A. i think now it's if either leg exceeds 50A it will trip both hot wires..


Doesn't really matter as your boat has a 30A breaker before the power enters the boat's systems.
 
Not that it makes any difference but the plug the OP linked to is 120 volt, 3 wire. Yes... a two pole 220 volt, 50A breaker will deliver 50A to each pole.
 
What JimG wrote is 100% accurate right down the line. If a fault occurs in the shore power cord, or in the boat's wiring before the main breaker, more than 30 amps could be supplied to that fault causing a dangerous overload problem for the wiring designed to only carry 30A. A properly designed adapter should have a 30A breaker or fuse as part of the adapter.

Best regards,
Frank
 
My question is the adapter a 125V or 250V. The 125v has one stud with a tabbed prong, the 250v has 2 tabbed prongs.

Adaptor 50A/125V to 30A/125V
110A.jpg
[FONT=Arial, Helvetica]Quantity in Basket: None
Code: MAR110A
Price: $116.99
Shipping Weight: 10.00 pounds
[/FONT] [FONT=Arial, Helvetica]Quantity: [/FONT] SHORE POWER CONNECTORS - ADAPTORS - PIGTAIL ADAPTORS: Female Connector: 30A 125V, Locking with Sealing Collar System, attaches to cordset or boat inlet. Male Plug: 50A 125V Locking, attaches to dockside receptacle or cordset. Adaptor 50A/125V to 30A/125V
110A.jpg
[FONT=Arial, Helvetica]Quantity in Basket: None
Code: MAR110A
Price: $116.99
Shipping Weight: 10.00 pounds
[/FONT] [FONT=Arial, Helvetica]Quantity: [/FONT] SHORE POWER CONNECTORS - ADAPTORS - PIGTAIL ADAPTORS: Female Connector: 30A 125V, Locking with Sealing Collar System, attaches to cordset or boat inlet. Male Plug: 50A 125V Locking, attaches to dockside receptacle or cordset.
 
ohsnow said:
My question is the adapter a 125V or 250V. The 125v has one stud with a tabbed prong, the 250v has 2 tabbed prongs.
Click to expand...

A 120 volt 30A plug has 3 connections - hot, neutral, and ground
A 220/240 volt 50 A plug has 4 connections - hot A, hot B, neutral, and ground.
 
Last edited:
JimG said:
A 120 volt plug has 3 prongs - hot, neutral, and ground
A 220/240 volt plug has 4 prongs - hot A, hot B, neutral, and ground.
Click to expand...


I think the 125/250 50A plug has three prongs, hot A, hot B, and neutral, the ground is a tab to the shell.
 
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