Great Loop Electrical Hook Ups

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sum escape

Senior Member
Joined
Jun 30, 2014
Messages
231
Location
Cruising, currently Longboat Key, FL
Vessel Name
Sapphire
Vessel Make
Tiara 53 Fly
In planning stage for Great Loop (Fall 2015 departure). Have 50 amp service on our new to us boat, a 2006 Grand Banks 47. I assume some of the AC equipment on my boat run on 220-240 volt and some on 110-120 volt? Or does 220 come into the boat only to be dropped to 110 for all service?
The reason I ask:
I plan to get a smart "Y" adapter (2 30 amp male to one 50 amp female) but my understanding is you need two 30 amp from same service to make it work. That's all fine if there are two available.
Let's say I get to a dock where only one 30 amp 110-120 volt service is available. If I had a single 30 amp male to 50 amp female pigtail, could I just power the 110-120 volt stuff?
What do experienced cruisers carry for hook ups?
Thanks.
 
not sure how you boat is wired...so can't answer if you have a true 250 panel....maybe a GB type can answer or over on the GB forum.

there are 30 to 50 125/250 adapters that will power both legs of the 50...but you'll really have to watch your usage.

I'm upgrading to a 50 125/250 and have both types of adapters
 
Pretty much ever GBs I've seen that have 50a service have 125/250 50a. Other than some old ones that by now I'm guessing have converted as you don't really see 125 50a service at marinas anymore.

Having a couple of adapters will be handy. But figure on running your Genset from time to time. Because even with adapters the voltage once you put a load on it can drop low enough that you are not going to want to use it anyway.

It used to be in some of the out of the way places you need a drier plug style 50a adapter. But I haven't seen that in quite a while. Maybe others can say.
 
This is a deal to get a yellow lined tablet, write down questions and get a knowledgable For hire person to come aboard. If these questions are being fielded here then I would suggest there are a lot more to be dealt with. Really, no disrespect, I found that the coin I spent was a good investment.
 
In planning stage for Great Loop (Fall 2015 departure). Have 50 amp service on our new to us boat, a 2006 Grand Banks 47. I assume some of the AC equipment on my boat run on 220-240 volt and some on 110-120 volt? Or does 220 come into the boat only to be dropped to 110 for all service?
The reason I ask:
I plan to get a smart "Y" adapter (2 30 amp male to one 50 amp female) but my understanding is you need two 30 amp from same service to make it work. That's all fine if there are two available.
Let's say I get to a dock where only one 30 amp 110-120 volt service is available. If I had a single 30 amp male to 50 amp female pigtail, could I just power the 110-120 volt stuff?
What do experienced cruisers carry for hook ups?
Thanks.
The reality is that that all boats with 50A 125/250V service have 2 legs of 110 come into the boat. Unless your interior panel SAYS 250..then you might just have 2 busses of 125V like this panel...but again...it's possible that you could have either and without a pic or someone who knows eyeballing it...we are at a standstill....
 

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As Psneed indicated, most likely you have 2 busses of 110 and no 220 appliances. However, when I tried to run off just one buss before hauling out, my AC water pump wouldn't run. There are 3 AC units on my boat, 2 on 1 buss, one on the other. They are all raw water cooled by the same pump. There is an electronic box that takes power from any of the 3 AC units and turns the pump on. It won't turn the pump on with only 1 buss powered and there aren't any 220 breakers on my panel. Will figure it out before I leave the yard. My point is things aren't always as simple as you would think.

BTW, with 220 50 amp converter boxes, the shore power needs to be 2 legs on different phases, not the same phase.

Ted
 
Sound like your pump gets it's power off the other leg of 125 along with that other A/C unit. Unless they are really large capacity units you should be able to power all three off one leg. That is the way my GB and most others are set up.
 
Tom, assuming you boat is set up like mine, which it probably is, you Air Con and hot water heater are 240V, and everything else is 120V split up between the two "halves" that make up 240V.

I think you are on the right track getting a Reverse-Y adapter. In addition, I highly recommend getting two 30A, 50' cords to use with it. We used ours a lot and found that the two 30A outlets you want are seldom close to each other. To get the Reverse-Y connected to the outlets, you need the 30A extension cords. Fortunately, they are relatively inexpensive at <$100 each.

A 30A to 50A 120/240V adapter can work, but you will not have Air Con or hot water. I never used one. If we couldn't get 240V directly or through the reverse-y, then we just ran the generator.

By the way, in Canada you will find 50A outlets are non-existant anywhere other than the major city marinas (Kingston, Montreal, Quebec). Pretty much everywhere else is 30A.
 
Tom, assuming you boat is set up like mine, which it probably is, you Air Con and hot water heater are 240V, and everything else is 120V split up between the two "halves" that make up 240V.

Very unlikely on a GB. Stock set up is to split the incoming 240v 50a to 2 legs of 120v. 1 for the A/C and 1 for "house" items like the water heater, charger, outlets, etc.
 
240 volt appliances will have double pole breakers. 120 volt appliances will have single pole breakers. Look at the electrical panel and you will know what's on your boat (assuming that you know the difference).

Or, check the label on appliances you suspect might be 240 volt like the range, water heater and airconditioner.
 
Most boats I have seen with true 220V and not just 2 - 110 legs have a separate panel for 220 appliances.

The types of breakers used may have one or two levers on them and could just be the 2 pole master for a 110 panel (poles connected breaking hot/neutral) or they could be 220 with a single or double throw (connected) with both hots to each terminal (again most of the time a separate panel).
 

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Our 50-amp service is split into two 125V legs as in Scott's first pic. No 220V appliances, all 100V.

The Smart Y works fine, when you can find two 30A connections out of phase with each other. (The idea of 30A extension cords is great.)

I know we can power one leg of our service with a simple 30A-to-50A adapter pigtail. I know which leg it powers (happens to be the one with the battery charger and oven/microwave). That seems to be arbitrary; no "leg selectors" available.

I'll mention that our aircon compressors/air handlers are each on a separate AC leg, so theoretically we could work ONE... but... the water pump is on the "leg not powered" by a single 30A input. Similarly, our 110V water heater and 110V range are also on the "leg not powered."

FWIW, an inverter somewhere in there could be an alternative to running the genset at a dock. (We don't have one.)

-Chris
 
Very unlikely on a GB. Stock set up is to split the incoming 240v 50a to 2 legs of 120v. 1 for the A/C and 1 for "house" items like the water heater, charger, outlets, etc.

I think we are miss-understanding each other. The GB 47's do indeed use 240V for the HVAC and for the hot water heater. These are 240V appliances. The AC service is also split into two separate 120V legs with 120V loads more or less balanced between them. It's just like a north american house.
 
I think we are miss-understanding each other. The GB 47's do indeed use 240V for the HVAC and for the hot water heater. These are 240V appliances. The AC service is also split into two separate 120V legs with 120V loads more or less balanced between them. It's just like a north american house.


No we where not misunderstanding each other. I was just misunderstanding that this boat was one of the newer GBs. :D. My bad.

I've never looked at their electrical set up. So it may very well have both 240 and 120 items on board.
 
No we where not misunderstanding each other. I was just misunderstanding that this boat was one of the newer GBs. :D. My bad.

I've never looked at their electrical set up. So it may very well have both 240 and 120 items on board.

Now I understand the that the misunderstanding was an understanding - or something like that....:)

The OP and I have the same model and vintage GB, though separated by 2 years I think. What I described is how my boat is set up, and hence very likely his too. But we have already found at least one equipment setup difference between the two boats, so it's certainly possible there are more.
 
Sum Escape
Going back to your original questions. On a 47 Grand Banks the likely 220/240 volt appliances would be an electric range and an electric clothes dryer. These can also be 110v or in the case of the range, propane. This is important to know because you will not get 220 volts from shore power everywhere on the loop.

What I suggest you have in terms of adapters is:

Smart Y for two 30amp shore power posts
30 amp from shore power to 50 amp adapter, this would end up 110v
15 amp from shore power to 30 amp adapter
There are locations on the loop where only 15 amp is available, it is better than nothing and will allow you to charge the batteries
30 amp 50ft shore power cord, allows you to attach smart Y to two different posts.
If your budget allows a second 50 amp shore power cord, you may have to go 100 feet for power is some locations.
50 or 100ft long 14 gauge household extension cord, again 15 amps is better than nothing and you don't want to drag 50 amp cables around when you can use a lighter weight 14 gauge extension cord.

In the 2/3rds of the loop I did, I used all of these and an old fashion RV type of plug
 
Please correct me if I'm wrong but even a smart splitter 2-30A to 125/250 50 A on the boat will still give 220V to appliances...you just have reduced capacity and as long as you have sufficient voltage split.
 
X2 on the 15A. When there is nothing else.
 
Bay Pelican,
You pretty much confirmed my thoughts on what I need. I did not have the extra 30 amp cord included (thanks to twistedtree too on that one) , the rest are already on the list.
Some power is better than none, especially when others may object to a running genset at the dock.
Thank you to all the contributors to this thread.
 
If you have a split 50, 1/2 panel powered by one 30 amp cord then the other side by the other 30 to have all outlets and systems powered by 30 amp shore power you need 1 of 2 things. 1. a panel with a parallel function to combine the 2sides or 2. A single 30 cord plug split to 2 30's to be plugged in at the boats 2 outlets. Just opposite of 50 to 2 30's at the pedestal. It is a 30 to 2 30's at the boat About $120 or so. Works fine on my Mainship.
 
An example of a 240v Panel.
ImageUploadedByTrawler Forum1408564176.460981.jpg
 
Different issue but bring at least 100 feet of water hose. 150 feet may be a better idea especially with a 47 foot boat which may be docked at the extremes of a marina.
 
At most of the Canadian locks where you pay to tie up ,15A -120v , a house sized socket was the norm.
Marina$ may be different.

Plan on anchoring out and running the noisemaker if a 15A lifestyle is not acceptable.

Same for most of the free docks on the Erie barge canal,15a house plug.
 
Plan on anchoring out and running the noisemaker if a 15A lifestyle is not acceptable.

Same for most of the free docks on the Erie barge canal,15a house plug.

Life will be easier if your boat can make use of the 15A to charge the batteries 24hrs a day and to the extent necessary you draw down the batteries to satisfy the peaks of a stove or coffee pot etc. Typical charger will put out more than 1200 AH per 24 hr period and that is enough for anything other than air conditioning. If you are going to be frequently in 15 A environments you can add a second shore power outlet that only serves one outlet on the boat to use for a charger or refrigeration and thus use two 15 A sources.
 
The real power hog , might consider one of the boosting inverters like the old Trace 2440 ? 4024?.

It was 4000w at 24v.

These can be set to the input amperage available , and will take power from the bat set to fill in if higher amperage is required., up to 4KW

The size of the house bank counts as a too high draw shortens the batt life.

The unit automatically recharges the house bank any time the draw is below the amps set point.

The work well, but load shedding , automatic or by switching is far cheaper .
 
Thanks for everyone's suggestions. I will be getting a smart y, a 30 to 50 amp adapter and already have a 15 to 30 amp adaptor. Will also purchase spare lengths of cords for each 50 and 30 amp.
My 120 side runs the battery charger so can get house charged while on a 15 amp service with careful power management. Inverter will work well for "incidental" needs while in this situation.
Without 50 amp service (unless the smart y will work and provide 220) we will be prepared for no A/C or hot water! Thanks
 
The smart Y works great for getting 240, but the two 30's have to be out of phase, which they typically are when both are on the same pedestal. The smart Y's like my Charles have a little indicator light. Remember, you just have 30 amps available when you do this.
 
240 volt appliances will have double pole breakers. 120 volt appliances will have single pole breakers. Look at the electrical panel and you will know what's on your boat (assuming that you know the difference).

Or, check the label on appliances you suspect might be 240 volt like the range, water heater and airconditioner.

Ron, did you mean double pole/double throw here?
 

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