Leaving Shore Power Connected.

Do you Leave Shore Power Connected and on when you are not on your boat

  • Yes I leave it connected and on

    Votes: 71 78.9%

  • No I switch of and or disconnect

    Votes: 19 21.1%
  • Total voters
    90
If you have an isolating transformer, leave it on.

If not, consider what an earth fault can do. Not all countries are as good as UK at making sure that the earth wire is at ground potential. Imagine your marina earth is running at, say seventy volts.
Think about how long a saildrive would last when submerged in salt water connected to plus seventy volts. Imagine what the drive would look like after say a month!

I can post pictures!

Disconnect it unless it is absolutely necessary.

Tony
 
Jabs said:
If you have an isolating transformer, leave it on.

If not, consider what an earth fault can do. Not all countries are as good as UK at making sure that the earth wire is at ground potential. Imagine your marina earth is running at, say seventy volts.
Think about how long a saildrive would last when submerged in salt water connected to plus seventy volts. Imagine what the drive would look like after say a month!

I can post pictures!

Disconnect it unless it is absolutely necessary.

Tony
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It doesn't have to be seventy volts - seven is plenty to cause serious electrolytic corrosion!
 
despite some of the more alarmist posts regarding high earth potentials/fires etc, I leave my shore power on if I am around for a few weeks/months (boats is in Spain, I live in the UK). I only leave on the fridges and the battery charger. I isolate all the 230V ac plugs and accesories just in case. (on my boat it's really easy to do that) However if I am going to leave the boat for a few months, I isolate the shore power on board, and leave the cable plugged into the shore power tower.
I don't isolate because I am worried by galvanic problems or fires as my boat has RCDs and Galvanic isolators. Or because of the risk of a significant earth wire voltage. Also the shore power tower now has an RCD as well.
After 18 years of boats, I now disconnect mains and isolate the batteries, if I am going out of the country. So that if someone unplugs the shore power (it happens) or the marina move the boat (it happens) I don't come back to flat batteries.

If all I wanted to do was to run a tube heater over the winter, then I would be quite happy using a suitable extension lead with an RCD just for the heater, if I was concerned about the state of my mains wiring. However I would be much happier winterising the engines/drives with antifreeze rather than relying on mains supply over the winter.
 
kashurst said:
despite some of the more alarmist posts............
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Not alarmist but basic observation through the media would imply that boat fires are a very real risk. There appears to be a super-yacht destroyed by fire every other week, in my own locale we have more boats destroyed by fire than any other means. Skimming the surface of this if there is an alternative way to avoid using mains electricity I'd recommend that route. If your mains charger goes you could just easily cause a battery fire. A small solar panel would do you wonders. It doesnt even need to be permanently fixed. I get the impression people leve mains on more as a matter of convenience and the belief that it wont happen to me. Our harbour rules specifically state no power may be left live on an unattended vessel on the (winter) hard. (we dont have electricity on the berths). This isnt without reason.
 
Is there a higher risk of a lightning strike which can damage the boats electric while keeping shore power on? And is it necessary to install a galvanic protection system. As you can imagine from my question I have disconnected the shore power until now...
 
Orthop said:
Is there a higher risk of a lightning strike which can damage the boats electric while keeping shore power on? And is it necessary to install a galvanic protection system. As you can imagine from my question I have disconnected the shore power until now...
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I seriously doubt that a shorepower connection has any effect on the probability of a lightening strike - the boat is floating in a pretty good conductor anyway. A galvanic isolator is generally considered to be a "good idea" to reduce the risk of rapid anode loss.
 
There is no increased risk of lightening strikes with shore power connected. A well built boat has all its external metal parts electrically connected to the anodes to act as a lightening rod (well sort off). Just in case I try to moor near/next to a sailing yacht -- if lightening is going to strike its more likely to hit a great big mast than your nav light rig. ;-)
Seriously though, galvanic protection devices reduce the chance of your boat acting as something else's anode. So yes a galvanic isolator is a really good idea and relatively cheap and easy to test, an isolation transformer is arguably better but they are heavy and expensive.
 
So there are 2 camps. Yes and no. The yes say for ( a) so batteries happy - and maybe they leave on fridges etc and (b) so if it sinks the batteries have a supply to keep it afloat longer.
The no say no mostly due to fire risk.

I think the fire risks is real But most fires seem to relate to de humidifiers ( as reported ) I don’t recall seeing on Re chargers ( doesn’t mean they don’t exist )

So it comes down to is it more likely to burn or sink ? I don’t know the answer but gut feel is sink.
 
I tend to leave the fridges off: when I bought my current boat one bank of batteries were shot. It turned out the previous owner had left the boat connected to shore power but with the fridges on, the shore line tripped (they had some lightening strikes in the marina which may have been the probable cause) leaving the fridges to run down the batteries for quite some time in summer. He did not visit the boat often once he had decided to sell.

Fire: My assessment of the risk of fire is its not that high with just the battery charger on, it should trip its breaker/fuses long before a fire develops and is unlikely to be in proximity to highly flammable materials.

Sinking: The risk of sinking is also quite low and somewhat minimised if batteries are fully charged and bilge pumps available.

Galvanic Corrosion: That leaves the galvanic corrosion argument mitigated to some extent by good bonding, anodes and a galvanic isolator, but is a moderately higher risk but for me one worth taking.
 
FWIW; I (still) always leave my boat connected (Princess 50/3) for the reasons previously stated. On my previous boat (Princess 45) the battery charger would have a brain fart from time to time and randomly throw full charge into the batteries when connected to shore power. Luckily we were on board both times and the only damage was two sets of house batteries but it could have been worse. Ironically, prior to my purchase my Princess 45 was damaged in a marina fire started on a boat two berths away.

My previous boat also had an issue where rain water would leak in through the belting strip, down over the top of the shore power connection in the cockpit and into the bilge. After a particularly heavy patch of rain the bilge began to fill, the bilge pump turned on but the water running over the shore power connection tripped the breaker. The bilge pump drained and trashed yet another set of batteries. Just fortunate that I visited the boat before things got too out of hand.

So... Sink or burn? Pick your poison but consider also that maybe the biggest threat is your neighbour's boat?

Cheers.

James.
 
It´s a pity that nobody answers my question. No matter, I made a query to my insurance company Pantenius.
My inquiry with the insurer showed that a damage due to a permanent unattended shore power connection can be rated as grossly negligent...
 
Orthop said:
My inquiry with the insurer showed that a damage due to a permanent unattended shore power connection can be rated as grossly negligent...
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''can be''... what does that mean exactly?
Are you suggesting insurance is invalidated if the boat is left unattended with shore power connected ?
 
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