Power

Mgm0304 · 02-20-2021, 09:30 AM

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?

RT Firefly · 02-20-2021, 09:33 AM

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

psneeld · 02-20-2021, 09:34 AM

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.

Sealife · 02-20-2021, 09:50 AM

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.

Woodland Hills · 02-20-2021, 09:53 AM

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.

DavidM · 02-20-2021, 10:02 AM

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

Mgm0304 · 02-20-2021, 10:09 AM

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

Sealife · 02-20-2021, 10:16 AM

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.

**Bacchus** · 02-20-2021, 10:16 AM

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?

Woodland Hills · 02-20-2021, 10:22 AM

Quote:

Originally Posted by DavidM

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

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.

SteveK · 02-20-2021, 10:53 AM

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.

Ski in NC · 02-20-2021, 12:22 PM

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.

High Wire · 02-20-2021, 12:28 PM

Welcome aboard! We like pictures.

rsn48 · 02-20-2021, 01:28 PM

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:

https://www.youtube.com/watch?v=Uj_am-ecSt4

caltexflanc · 02-20-2021, 07:09 PM

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.

Spike · 02-20-2021, 08:16 PM

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.

DrissZougari · 02-20-2021, 08:18 PM

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.

Spike · 02-20-2021, 08:25 PM

Got it...Google is my friend!

bglad · 02-20-2021, 08:27 PM

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.

Quote:

Originally Posted by Mgm0304

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?

tiltrider1 · 02-20-2021, 08:43 PM

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.