is OK to leave shore power connected ?

[Pete7]

Originally Posted by valhalla360

Considering this is a thread about what happens when you LEAVE...that's not much help if a fitting fails Monday and you won't be back until Friday.

If it won't float for a week on its own without pumping out, then there is a problem.

[sailingchiro]

Originally Posted by CptCrunchie

Better yet, here us a thread from a little while back that explains in great detail the reasons the set up you are using is a very bad idea.

Maybe I am wrong but the battery charger acts as an isolation transformer from AC to DC side. The ground is connected and I agree but that will act for the leakage current the GFCI that is used at the end of my shore power will pick that up. I have had it tested for leakage at my boat and this setup had no leakage at all. Our marina is setup with the new codes for leakage current and is extremely sensitive. The problem with leakage current is when white and green are connected. I have checked the impedance between the two and it is open. This is a great topic since we do have a lot of problems with leakage at docks. I feel sorry for the divers that clean our boats.
I had to check all my white to green connection and found 3 connections. Oddly they all ran back to the inverter charger. I found the inverter charger if not used the white and green are connected until shore power is applied but it reacted too slow and shut down the marina. The page you referenced is for using a shore power cord. I am using a shore power cord and not an orange house cord. Remember, the black wire is not connected to anything on my boat, only the green wire. This won't allow any current to pass through without a complete circuit. The other connection for the white and green is the generator. I disconnect the battery to the generator when away. I may stand humbly corrected but have done a fair amount of research on this topic out of need. I did this setup because my neighbor has a orange cord running to his boat running an A/C all the time. I stopped eating zincs. Haven't replaced since.

[valhalla360]

Originally Posted by Pete7

If it won't float for a week on its own without pumping out, then there is a problem.

Agreed, that's why keeping it on shore power, so it can keep pumping if a fitting breaks right after you drive away is a good thing.

Hopefully someone notices that it's been pumping constantly and notifies the marina who can take action.

[hellosailor]

Also depends on where you are. Sometimes a neighbor will unplug you in order to access power from that outlet and oops, forget to plug you back in. Some yards swear it is local fire code that unattended boats be unplugged. Might actually just be that their insurer, or their owner, is happier that unattended boats aren't plugged in, that can be a fire hazard. (Overcharging batteries is all that you need to set the marina on fire.)

And then of course, if you are plugged in and there's a power surge...what happens on your boat.

No one best answer, it depends on whether you need that shore power.

[rbk]

Originally Posted by CptCrunchie

Not so. 'Electrolysis' ..which is actually galvanic corrosion ....comes from being plugged into shore power, not whether you turn everything unneeded off. The green 'ground' wire connects every boat in the marina together. So, if you have one boat leaking a lot of energy, it could easily use your boat as a sacrificial anode. A galvanic isolator on your green ground wire right after it enters your boat will help, but it can still fail.

I'm surprised no one has clarified or corrected this yet. Electrolysis is not galvanic corrosion or vice versa (quite the opposite actually) and the original poster was most likely referring to stray current corrosion. While part of the above statement is true it is somewhat misleading in that if for example you were to leave your shore power plugged in and charging batteries with DC circuits active and a substantial electrical leak (bilge pump for instance) with current leaking through your shaft/prop you would find yourself without a prop/shaft in short order (depending on amount of current).
A boat doesn't need to be 'leaky' to use your anodes as their own, just lack of regular replacement of their own anodes will do it. Once their anodes are gone, the common ground of the shore power allows them to start eating up their neighbors anodes instead, that's where an galvanic isolator or an isolation transformer can help.
If you had a very electrically 'leaky' boat as described above you could in theory replicate electrolysis ( via electroplating) but would require the right combination of electrolyte (seawater),metals and current flow to make it happen.
It drives me nuts seeing a zinc and cable thrown overboard in marinas (especially mine), fix your f**king boat.

[waterman46]

Originally Posted by rbk

It drives me nuts seeing a zinc and cable thrown overboard in marinas (especially mine), fix your f**kifng boat.

A neighbor hanging a grounded zinc, in itself has zero effect on your boat. Assuming he has zincs in the normal places already. Seems like you assume he must have a problem, knows his zincs are gone.or he would not do that.
I would guess that most who do that simply want a bit of extra protection even if their regular attached zincs have not been eaten up fast. If they do have too short life on their zincs, it requires some measurements both at the dock and away from the dock to determine the cause, a procedure that most boaters won't know about or be bothered with. So they just hang a zinc as extra protection.

Isolation transformers seem to be recommended as a cureall for stray current protection in marinas. When using one, I assume the ground wire from the marina is not connected through to the boat's ground, is that correct?

[redneckrob]

Originally Posted by waterman46

A neighbor hanging a grounded zinc, in itself has zero effect on your boat. Assuming he has zincs in the normal places already. Seems like you assume he must have a problem, knows his zincs are gone.or he would not do that.
I would guess that most who do that simply want a bit of extra protection even if their regular attached zincs have not been eaten up fast. If they do have too short life on their zincs, it requires some measurements both at the dock and away from the dock to determine the cause, a procedure that most boaters won't know about or be bothered with. So they just hang a zinc as extra protection.

Isolation transformers seem to be recommended as a cureall for stray current protection in marinas. When using one, I assume the ground wire from the marina is not connected through to the boat's ground, is that correct?

I know lots of folks that hang the zinc over the side because they think they're supposed to and don't really know why. I agree it probably doesn't mean they think they have a problem.

[newhaul]

Originally Posted by rbk

It drives me nuts seeing a zinc and cable thrown overboard in marinas (especially mine), fix your f**king boat.

then you would be in serious need of a straight jacket near my boats. I don't even plug my boat into shore power but I still hang a guppie .

[rbk]

Generally people hang them because their anodes are wasting away due to stray current or just plain reluctancy to replace them, as pointed out most have no idea why their anodes are wasting away (along with their neighboring boats) or those that don’t bother, don’t really give a sh*t. ‘Oh my anodes didn’t last six months this year, better add a bunch more’ I’ve heard this far too often, there is a problem, find it and fix it, it may be that derelict boat slipped next to you, it could be a potential life or boat threat in your boat.

[newhaul]

Originally Posted by rbk

Generally people hang them because their anodes are wasting away due to stray current or just plain reluctancy to replace them, as pointed out most have no idea why their anodes are wasting away (along with their neighboring boats) or those that don’t bother, don’t really give a sh*t. ‘Oh my anodes didn’t last six months this year, better add a bunch more’ I’ve heard this far too often, there is a problem, find it and fix it, it may be that derelict boat slipped next to you, it could be a potential life or boat threat in your boat.

one has no control over the conditions on another's vessel just his ( my) own vessel to mitigate the effects as best we can.

[rbk]

Originally Posted by newhaul

one has no control over the conditions on another's vessel just his ( my) own vessel to mitigate the effects as best we can.

Agreed, but you’d eliminate your boat as the culprit first not just through a zinc brick over the side. Best you can do with sh*tty neighbors is add an isolator and unplug from shore power whenever possible.

[Mauruuru]

A galvanic isolator and properly wired shore power, properly protected AC and DC circuitry and fuses at Battery terminals there should be no problem.....three boats over 30 years never had an issue leaving the battery charger running while away from the boat....

[svmariane]

Shore power? Phffft... We installed solar panels and a wind turbine so that "we don't need no stinking shore power".

When docked and we leave the boat the only breakers turned on are for the re-charge systems to function and for the bilge pumps to work. Well, plus those breakers needed to start the motor so some kind soul can drive the boat away from a neighboring vessel that caught afire!

It helps to have a high-capacity battery bank - you know, for cloudy/windless days. Also, actually we're cruisers, not racers, and accepted the trade-off in performance by having that extra "stuff" mounted aft. As if I'd even notice the diff!

Just saying how we chose to deal with the problem. Others have posted good advice if using shore power is your preferred option.

[kiwiaviator]

I remotely monitor my voltages, bilge pump operation, etc using a Raspberry Pi computer with a 3G modem. Wasn't hard to setup including email alarms. There are commercial solutions out there too. IoT (internet of things) is a rapidly growing field and can apply to our vessels.

[NSboatman]

Kiwi- I'm interested in this monitoring setup. Can you share schematics/layout/part no's/code? What's your monthly 3G fee for the sim?