Power

I have a 1988 50 ft Chris craft constellation. We just bought in and we were told we only needed to use 1 50 amp, not 2 for power. The powers trips every once in awhile so I am wondering if we should use both 50 amps. We are live aboard so we need power. Does anyon have any insight?

Greetings,
Welcome aboard. Under what conditions does it trip? Any problem with simply plugging in the 2-50amp and leaving it?

There is no way to tell based on your possible power demands and how the boat is wired.


Who told you what you "need" or don't need?


Many have really no great understanding of electrical including many marine professionals with marine electricians possible being one of the exceptions.

Anyway you need to know what the amperage is on the circuits. I’d recommend knowing branch and mains. You also need to determine which circuits are on which main etc. although the circuits on the second main will be dead, unless there is any crossover (Scary).

If the cord/connections are old/burnt/corroded that could also contribute to premature tripping, although few would recommend pulling 100% amperage thru a shore power cord for any length of time.

You can either manually manage your electrical loads or you can use two cords to spread the load between two panels. A lot will depend upon how your boat is wired.
When we are on the move and are staying in a given marina overnight only we use a single 50a cord, if we are staying a while or if we are having overnight guests we will use two. It is nice to be able to run all six air conditioners as well as the washer and dryer without having to go to the pedestal to reset.

I am a little puzzled by what you mean by two 50 amp. Does this mean you have two 50 amp power connectors on your boat?

I am familiar with biggish boats (up to 48') that have a single 50A connector. I am not familiar with nor do I see how two 50A connectors can work.

David

Thank you for your reply. It is very inconsistent but this morning I had the coffee maker and dryer on and it tripped

We have not tried to use both

Mike I assume. You need to know the amperages. The main panel should have a meter for this. If it goes over 50 main breaker should trip, indicating you are overloading the main breaker. This is unrelated to the branch breakers. If less than 50, you may have a weak main breaker or a wiring issue. Without amperage readings you can’t know and/or maximize your power usage safely.

If you can post a photo of your elec breaker panel and the inlets it might help.
Most 50A boat inlets use 50A 240V that provides 2 50A 125V feeds to separate sides of an elec panel.
I have seen one older (80s) Carver that had two 50A 125V inlets but that is not common.
Where are you tripping... pedestal, main breaker or individual circuits?

DavidM said:

I am a little puzzled by what you mean by two 50 amp. Does this mean you have two 50 amp power connectors on your boat?

I am familiar with biggish boats (up to 48') that have a single 50A connector. I am not familiar with nor do I see how two 50A connectors can work.

David

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Our Hatteras has ac panels A & B and sources 1 & 2, you can power both panels from either source/cord or you can power either panel from either source. FYI, we have a 100’ cord (source A) in a power reel at the bow and two receptacles in the cockpit. There were two cords in the bow when we acquired the boat, but we removed one to expand the chain locker. We have a 25’ and a 50’ cord to use for the cockpit receptacles when needed.

I remember when land homes had a 60 amp main breaker.
A dryer and coffee pot is not 50 amp. Something else is going on.

So what is tripping? Dock GFCI or 50A breaker in boat? Does it trip when load is high, or trip randomly?

Lots of boats with two 50A inlets are set up to use one or the other, and not split load between the two. Depends on how the panel is wired. Post a pic of panel, might be able to help.

Welcome aboard! We like pictures.

In my world, 50 amps is a lot. Having your power trip is actually a blessing in disguise, I've done so on my boat 7 times since last August. You are forced into thinking about power management even though you don't want to. I find when I am with new boat owners (newer to boating in general) and I start talking about power management, their face glazes over and they begin to think about more important things like - what's for lunch?

The best thing to do here is list every electrical devise you have, don't forget the inverter and the charger. And don't just list refrigerator, for example, but how big is it and is it AC or DC or both.

Then list what you have on in an average day, especially when you have tripped a breaker.

Learn to think in amp/hours, not difficult to do, there are charts all over. I think I might have a Ranger Tug tutorial for power management you might find helpful:

Actually a dryer and a coffee maker could be more than 50 amp..... 125 volt that is. Remember some older boats had that.

We need to know a whole lot more from the OP, or he needs to get a competent marine electrician on board to scope it all out for him.

Like Woodland Hills we could run 2 50 amp / 250 volt lines and divide the loads up among various panels. Not that that is relevant to the situation at hand here in any way.

I have a 1986 46' Connie which should be the same set-up. On ours we have 2 50 amp inlets on either side. One is 50A/240V and the other is 50A/120V. I have found very few marinas that have the 50A/125V outlet in a power pedestal. On our panel the Power selector switch has SP 1 (240V) and SP 2 (120V). Position 1 had SP 1 & SP 2 so I assume you could use 2 cords if your marina power had the 120V option available.

That being said, I have never used the 120V inlet and have no problem running everything on the boat. If you are using the resistance heaters along with other appliances maybe that could be a high draw. I would think that if you are tripping the main breaker you have another issue assuming you are getting the proper voltage and amps from the pedestal all the way to the main panel.

I have attached a picture of our panel, yours should be similar. (Sorry, just found that a HEIC file is not supported, anyone have a fix for this?)

Hope this helps.

please hire a qualified marine electrician to check your boat and hopefully will be able to explain to how your boat is wired. It could be a chip as a breaker but you do need to understand how your specific boat is wired.

Got it...Google is my friend!

Some boats from that era had two 120-volt 50-amp cords. 120-volt 50-amp is not common these days except on lakes. It is not too onerous to switch to one 240-volt 50-amp. Then, you would be fine with one cord giving a total of 100-amps at 120 versus 50. I doubt very much that boat came originally equipped with 2 x 240-volt 50-amp cords.

Mgm0304 said:

I have a 1988 50 ft Chris craft constellation. We just bought in and we were told we only needed to use 1 50 amp, not 2 for power. The powers trips every once in awhile so I am wondering if we should use both 50 amps. We are live aboard so we need power. Does anyon have any insight?

Click to expand...

We need more information from the OP. As asked by others we need to know what the Dock pedestal has for power. Is it 30 amp or 50 amp and if its 50 amp is it 50a 125v or 50a 125-250v.

That is the easy question. The more difficult question is what are the power receptacles on the boat and what switches do they go through to get to the panel.

Then a good photograph of the Electrical panel would be helpful. Also, knowing what your electrical demands are would also be helpful.

I forgot to ask, what trips? Breaker on the dock or on the boat. If on the boat which breaker.

The big power draws are resistance style heat, water heater, dryers, electric stoves, air conditioners/heat pumps.

For instance on my boat I run a 50a 125-250v power cord. This is one cord but it gives me two legs of 50a 125v power on the boat. One leg runs the hot water heater, battery charger, kitchen appliances (not the stove its propane), lights, outlets and a single 750w portable heater. The other leg runs 3 heat pumps, two resistance heaters and washer/dryer. The resistance heaters and the washer/dryer are on an either or switch.

Even 50a 125-250v has its limits for winter liveaboarding. I usually recommend diesel heat systems over heating with electricity. Unless you live in the warmer parts of the country it is really hard to heat solely with electricity. I use 2 very efficient heat pumps and two 750w resistance heaters. This works most of the time here in Seattle were the water is always 49 degrees and the air temp is rarely below 40 degrees. When the temperature drops below 40 degrees I turn on the diesel furnace.

rsn48 said:

In my world, 50 amps is a lot.

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Massive in our parts as well.
We only have a single 15amp to run everything on shore power.

Spike said:

I have a 1986 46' Connie which should be the same set-up. On ours we have 2 50 amp inlets on either side. One is 50A/240V and the other is 50A/120V. I have found very few marinas that have the 50A/125V outlet in a power pedestal. On our panel the Power selector switch has SP 1 (240V) and SP 2 (120V). Position 1 had SP 1 & SP 2 so I assume you could use 2 cords if your marina power had the 120V option available.

That being said, I have never used the 120V inlet and have no problem running everything on the boat. If you are using the resistance heaters along with other appliances maybe that could be a high draw. I would think that if you are tripping the main breaker you have another issue assuming you are getting the proper voltage and amps from the pedestal all the way to the main panel.

I have attached a picture of our panel, yours should be similar. (Sorry, just found that a HEIC file is not supported, anyone have a fix for this?)

Hope this helps.

Click to expand...

I have seen boats that had two 30a receptacles on one side, a 50a 125v receptacle on the other side and a 50a 125-250v receptacle on the stern. It took me a whole day to figure out how it was wired and how all the switches had to be thrown to make everything work. In the end we removed the two 30a receptacles, replaced the 50a 125v with a 50a 125-250v receptacle and wired both receptacles to a Shore/Generator switch that was properly marked for Bow and Stern. We then supplied the boat with 30a to 50a splitter making it less complex.

Back in the 1980's we used to see everything from 15a, 20a, 30a and 50a 125v. Now things are more uniform with 30a 125v and 50a 125-250v.

You can get adapters that hook a 50 amp 125v connecter to a 30 amp shore pedestal. I'm still not sure I understand how you use both and divide up the loads between them on the Chris Crafts described and pictured in this thread. I understand why they gave you the option back in the day.

I am curious about the statement to the effect that having a crossover between two individual power inlets being scary .

I have two separate 30 amp power inlets. I typically only use inlet A because it’s the smart plug inlet.

I use the crossover switch when I want to run the washing machine (on my “B” panel) off of my normal “A” inlet. I am pretty careful and watch the gauges to avoid overloading anything. Is there some other risk that I am not aware of?

Thanks!!

Sue, you have nothing to worry about. Your boat has been inspected by a qualified marine electrical engineer. He would not have allowed your boat to leave the dock if it was wired stupid.

Also, I believe you are miss interpreting what was meant by cross over current.

Thanks Dave. The switch that combines both AC panels is labeled, as I recall, a crossover. If that isn’t what the previous post was referring to, did it refer to an inadvertent connection between the two AC panels where both are energized even if not intended? I guess that would be scary! I don’t know that the wiring on my boat is more reliable that any other boat wiring, but thanks for the vote of confidence!

It was inferred that both receptacles were wired together with no switch. Meaning that if you plugged into one it made the other live. The safety issue is that the unused receptacle was live. The other issue is if some one accidentally plugged in a second wire there would suddenly be 240v instead of 120v. While neither of these are likely to ever occur, if either did occur the result could be anything from nothing to expensive to deadly.

BAsed on the year and size of the OP's boat, I bet it has 2 125V 50 amp inlets and a switch that lets you combine loads on th AC breaker panel so that every breaker in energized by just one of the 125V 50amp inlets. This allows anything to be run on AC, but you will have to manage loads becaase you only have half the power the boat can handle.



One fix is to get a Y splitter that has a 125V/250V 50A male connector on the single end and a pair of 125A 50A female connectors on the double ends, and get a standard 125V/250V shore power cord (you can modify one of your 125V 50A cords by changing the plugs on both ends to convert them to standard 125/250V cords) Move the AC panel switch from one input to two inputs, then connect the double ends to the boat's two 125V inlets then use a standard 125V/250V 50A cord between the Y and the 250V 50A power outlet on the dock. The advantage here is that you double your power, but still have just one cord.



Another fix is to get a Y splitter that has a 125V/250V 50A male connector on the single end and a pair of 125A 50A female connectors on the double ends and use your pair of 125V 50A cords with it to power the boat. Move the AC panel switch from one input to two inputs, then connect the two 125V 50A cords to the boat's two 125V inlets. Connect the male end of the Y adapter to the 250V 50A power outlet on the dock.and the two female ends to your two cords. In this configuration, you have doubled your power, but you have to use two, big, heavy cords.

Actually what the OP has is one 125V/50A and one 240V/50A inlet on each side of the boat by the entry door. Sorry if it wasn't clear in my earlier post. I've changed both 240V inlets to the smart plug and have never used the 125V inlet. The one cord powers everything on the panel with no problem. The only time I've had to "load manage" is in the rare times there was only a 30A plug on the dock pedestal and I had to use an adapter.

Mgm0304 said:

I have a 1988 50 ft Chris craft constellation. We just bought in and we were told we only needed to use 1 50 amp, not 2 for power. The powers trips every once in awhile so I am wondering if we should use both 50 amps. We are live aboard so we need power. Does anyon have any insight?

Click to expand...

How old are the breakers? If they are original then they are over 30 years old. If all the wiring is corrosion free and the grounds are good and you know it's not an overload problem (Do your math) then the breaker may not be up to snuff so to speak. They can become weak also with age.