Leaving boat plugged in and power on when leaving boat

[stormalong]

I leave the power on, including water heater, heat, and an automatic battery charger. It is near the 30 amp limit. I leave the hot water on because the water from the engine loop into the hot water tank works in reverse to warm the engine block and engine space enough that I don't winterize the engine.

The one thing I have learned from living aboard in some very harsh winters is to replace the standard power inlet with a Smartplug. I have heat damaged the old style receptacle at least three times. Never had a fire but may have come close. I don't live aboard anymore and where I live has more moderate winters but still have similar electrical loads so I feel safer with the Smartplug.

Disclaimer: I have no connection with Smatplug, just a happy customer.

[Greatest Lakes]

Originally Posted by dave907

In Florida, unfortunately, it's a good idea to leave the power on and the Air Conditioning going (set to 78-80 degrees) when not onboard. If I don't, the inside of the boat gets so hot it starts melting things (like the glue of the head liners, etc.). Also, the AC keeps the humidity down.

I've had the raw water intake clog before, but the units shut down automatically when this happens.

Dave

Well. That's horrifying. I'm in Michigan. We leave the charger on since it just maintains the battery. I've left the fridge running for a few nights if I was around, but usually it stays off. I do leave a fan running on AC and there is a solar dorade fan in the head that runs constantly when away. I'm now pleased I dont have to think about my boat interior melting!

[Hudson Force]

Originally Posted by valhalla360

No it's correcting misleading info.

Your house sits stationary (short of earth quakes).

A boat is constantly shifting and moving in the slip. That applies forces to electrical connections.

But just because the analogy isn't correct, doesn't mean you can't safely leave the boat plugged in.

It's balancing risk vs reward.

We generally turn off everything but the fridge and battery charger. For the circuits that are off, the risk is reduced but turning the fridge off would result in having to do something with the food and keeping the batteries charged means the bilge pumps have near limitless run time.

This constant movement is an important consideration and a wise message from Valhalla. This is increased with wakes, floating docks, and even people walking on the finger piers. This flexing of wiring is why braided wiring is the proper code for marine use and not romex.

It was always my habit to secure my power cord with a piece of line close to the pedestal plug as well as at its last point laying on the dock and it's first point aboard and always with more slack than what could be pulled taut with the stretch of the dock lines. I also had the habit of gripping the shore plug briefly with my hand when walking by to be assured that it was not hot. The positive, negative and neutral ground prongs on the shore power plug should remain well seated and firm without corrosion. I'm always distrustful of the marina powers sources with black scorched marks and double check for a loose connection to these or heating of the plug.

[KenKo]

Good point about the relative danger of driving to the marina, but it might have some loose relationship to how far you live from the marina!!

[ArmyDaveNY]

There are many good comments here, however an important consideration is the condition of your equipment. According to Boat U.S., of the electrical fires on a boat (which account for around half of all boat fires where the cause can be identified), just over half start from a problem with shore power.

I am NOT saying this to suggest that you can't or shouldn't leave it plugged in. What I am suggesting is that if you leave it plugged in, you need to make sure everything is in good order with the appropriate protections. I have seen a number of burnt out shore power cables at various marinas.

I used to leave mine plugged in regardless of how long I was away from the boat and had no issues. Most people have no problems. I do suggest, as others here have, that you ensure that your connections are in good condition with the proper breakers.

Please note that Marinco specifies that the continuous load should be no more than 80% of the system's rated power, especially the cable's rated power. If you have a 30A shore power cable, you shouldn't be continuously drawing more than 24A. Marine How-To suggests no more than 70% or 21A. I would also change from the typical 3 prong plug to a smart plug. (No, I am not selling these!).

As others have said, you should have no issues with a good system and shorter trips away from the boat. For longer trips, I would shut most things down and disconnect. Good luck with what ever you decide to do.

[S/V Illusion]

Summary of what I have learned here:
1. some don't know the difference between "there" and "their",
2. Some people conflate "lightning" with "lightening",

3. boats move, houses don't and the earth is rotating at 800 MPH so everything is relative.

[bailsout]

My marina asks that no boat leaves an unattended boat plugged in. Maybe that practice helps keep the damage from stray current at bay.

[StuM]

Originally Posted by S/V Illusion

3. boats move, houses don't and the earth is rotating at 800 MPH so everything is relative.

Only at ±39.5° latitude

[Celestialsailor]

The only thing I would disconnect/turn off, when leaving the boat if it were at the dock, would be a water supply. That has been attributed to sinking a boat in the slip.

[belizesailor]

Originally Posted by S/V Illusion

Summary of what I have learned here:
1. some don't know the difference between "there" and "their",
2. Some people conflate "lightning" with "lightening",

3. boats move, houses don't and the earth is rotating at 800 MPH so everything is relative.

All valid points for something...but none very relevant here.

[joelhemington]

Originally Posted by sailingabe41ds

I am in California The way our electrical grid works here with recurrent power outages and the poor maintainance in my marina maybe California should be added to Panama and Columbia as high risk areas to leave your boat plugged in.

Abe

Boy, you got that right Abe. Somehow I don't think Tesla envisioned we'd using alternating current in this way. Every time it rains or the wind blows, the power goes out around here. We just can't have nice things anymore though I'm sure Best Buy is not complaining

[chrisr]

we're very rarely on a marina but when we are, have no hesitation to leave boat plugged in and everything on - although we only leave the boat for 1-2 days so it's a bit academic

however i do recall a boat plugged in to shore power ('Silent Night', at the cyca i think ?) catching fire when the battery charger cooked itself

i'm still happy to leave the boat plugged in, but only because i'm confident in our equipment

cheers,

[JasonS]

AC and water get turned off when we leave and thru hulls closed. If a hose or fitting breaks, you have a messy flooded boat at best and a sunk one at worst

[sailingabe41ds]

Originally Posted by Ericson38

I'm fixing to launch our Taswell 49 in Oxnard in a few months (cross country move from Virginia). I just went through some brownouts at the house in northern Santa Barbara county and I guess that happens in Ventura county too. TV commercials are already talking about not using power in certain times of the day, and there are pictures of fun loving folks hanging clothes on the line in a nice sea breeze, all having fun, playing frizbee, balloons, that kind of stuff.

With the brownouts, the house lighting got dim but stayed on. I was worried about the fridge motor but didn't unplug it. Not leaving the boat plugged in.

Welcome to California....the population had doubled but they do not build any more powerplants. We have to buy electricity from other states.. My parents live in Florida and they run the A/C almost year round they do not have these issues. This is a third world country when we should be leading the nation. Well, we do lead in homeless, welfare, taxes, and I think we are first in last place in education.

Abe

[StuM]

Originally Posted by JasonS

AC and water get turned off when we leave and thru hulls closed. If a hose or fitting breaks, you have a messy flooded boat at best and a sunk one at worst

I'd never leave water connected and turned on whether the boat is occupied or not.Water is never connected except when filling tanks
Worst case several hundred litres of water transferred from tanks to bilge(s).