Dock electrical ??

rbcool · Post by **rbcool** » Tue Aug 28, 2012 7:43 am

Has anybody noticed this at their marinas?
At least 7 boats, in different positions and including mine, have experienced at least one of their female plug holes being burned-blackened. And one male prong pitted. This has happened over the past year. A few of the cords are fairly new and YES..... we all know to turn the plug when plugging in.
Also.... several boats report (mine as well) that the zincs on the STBD side are getting eaten up WAY faster than the Port, doesn't matter which side of the dock they are on.
Our (master

) electrician here has used his little volt meter and proclaimed nothing is wrong.

Ron

rbcool · Post by **rbcool** » Tue Aug 28, 2012 7:44 am

In some cases it's the ground, others not

Ron

aaronbocknek · Post by **aaronbocknek** » Tue Aug 28, 2012 7:47 am

nothing wrong my radiation burned tush! how many electrical cords are hanging in the water from other vessels? is there a 'marina cable' touching the water? i'd be curious to trace this thing out.

Stripermann2 · Post by **Stripermann2** » Tue Aug 28, 2012 7:55 am

Do you have any derilict boats on the dock? Perhaps your issue is with a improperly wired boat which is passing this current into the water and surrounding boats?

aaronbocknek · Post by **aaronbocknek** » Tue Aug 28, 2012 8:01 am

Stripermann2 wrote:Do you have any derilict boats on the dock? Perhaps your issue is with a improperly wired boat which is passing this current into the water and surrounding boats?

ahhh good suggestion jamie. now, which thread do i/we respond to? there are two with the exact same title and question.
aaron

P-Dogg · Post by **P-Dogg** » Tue Aug 28, 2012 8:58 am

Here's a little trick to help find where the problem is. Ideally, you'll want to do this on every "nearby" boat. I'm not sure what "nearby" means, but the stories I've read about swimmers being electrocuted in marinas lead me to believe that it is on the order of 30 feet, so you might want to start there. But don't get hung-up on distance.

First, leave the voltmeter in the toolbox.

Take a clamp-on AMMETER and put it around the shore power cord(s) of the subject boat.

Turn on every AC device on the subject boat (this may need to be done in phases) and make sure it is drawing power. Be sure to run hot water so that the water heater powers-up.

Read the value on the ammeter.

Since the ammeter is clamped around all of the incoming and outgoing wires, the induced current in will be cancelled by the induced current out, that is why to "properly" use a clamp-on meter (to measure the current in a conductor), you need to ensure that it clamped around just one conductor.

There should be (almost) no current detected by the meter (everything has a leakage current -- there is no perfect ground). That is, unless current is leaking out of the boat and into the water, or out of the water and into the boat (because it is serving as a ground for a nearby boat with a faulty ground of its own).

The meter won't tell you which way the current is going, but if the value is non-zero, go around and unplug other boats' shore power until you get "zero" ( it is unlikely that you'll get exactly 0.00 on the meter). That is the boat with the problem (assuming that it is not your boat-- which can easily be verified by performing this test on the adjacent boat and unplugging YOUR shore power to see if their meter suddenly reads "0.00").

If you carry-out this experiment, please report the results. I know that ABYC is concerned about 1.5 amps.

Stripermann2 · Post by **Stripermann2** » Tue Aug 28, 2012 11:25 am

Unfortunetly, going around and just unplugging other boat's shore power is a no-no. Unless you have their approval! Would you want someone to just walk up and unplug your power?

But your application seems right on...

prowlersfish · Post by **prowlersfish** » Tue Aug 28, 2012 11:38 am

When a cord burns up its due to high resistance at the point where it burns or a overload . In the case where it burns at the plug in most cases its due to burnt or lose contacts in the female receptacle all the meters in the won't tell you that. You can burn up a brand new cord due to a bad receptacle .

Its rare that the boat would a issue . Even if there are several boats with the same issues , you many have a lot worn receptacles . a GOOD idea is to do a drag test on the terminals in the receptacle along with a visual and voltage test .

due to the cost of these receptacles It seems marinas don't repalace them when needed . We have to raise hell to get one replace .

its always a good idea to replace the plug when replaceing the receptacle. if ther is any damage .

koviak · Post by **koviak** » Tue Aug 28, 2012 11:45 am

Burned plugs means to outlet is worn and not making contact properly. Was having the same issue with zincs being rapidly destroyed. Installed a galvanic isolater 2 years ago and problem went away. Lots of old sailboats near me with old and spliced cords that I know are the issue. Community dock so I can only suggest replacing there cords. I lost a very close friend to electrical shock at a pier due to this. If at a marina push the issue for outlet replacement it's what you pay for. Most electricians bave little knowledge of the marine enviroment.

Dennis (master electrician)

rooferdave · Post by **rooferdave** » Tue Aug 28, 2012 12:09 pm

what is this galvanic isolater you speak of???

where does it go?

how does it help?

Commissionpoint · Post by **Commissionpoint** » Tue Aug 28, 2012 12:34 pm

Stripermann2 wrote:Unfortunetly, going around and just unplugging other boat's shore power is a no-no.

Says who? In my book keeping your property in a condition that damages my property is a "no-no". If unplugging you keeps me and the rest of the dock from taking collateral damage consider yourself unplugged. If you continue to not make repairs and insist on plugging back in and causing more damage to others property you may find yourself without a shore power cord.

I'm not advocationg vandalism, steeling, or anything like that, but if somebody keeps doing something stupid and you are suffering damage to your own property as a result you have to take matters into your own hands sometimes.

P-Dogg · Post by **P-Dogg** » Tue Aug 28, 2012 12:52 pm

Unfortunetly, going around and just unplugging other boat's shore power is a no-no. Unless you have their approval!

Well, quite frankly I envisioned this to be a team effort amongst fellow boat owners and/or the marina operator. That said, I noticed that Tuesday nights are pretty quiet around my marina.....

prowlersfish · Post by **prowlersfish** » Tue Aug 28, 2012 1:25 pm

P-Dogg wrote:
Unfortunetly, going around and just unplugging other boat's shore power is a no-no. Unless you have their approval!
Well, quite frankly I envisioned this to be a team effort amongst fellow boat owners and/or the marina operator. That said, I noticed that Tuesday nights are pretty quiet around my marina.....

mostly agreed , but you you should never unplug about with out the owners or marina management approval ( unless you see smoke of course ) anyone that would just unplug a boat even for a quick test should be reported to the marina management , as many boats have systems that need to be reset . Unless I know you and it was my boat there would be hell to pay .

koviak · Post by **koviak** » Tue Aug 28, 2012 1:33 pm

Rooferdave, the isolater is installed on the ground of your incoming shorepower circuit. Diodes in the unit only allow current flow in one direction so it isolates your system from others. Remember electric will go to the closest ground source, taking your boat out of this link will save your underwater metals. Hell it's so bad where I am at a 46ft. Sailboat lost his rudder at the dock to corrosion. Search on line for units, remember (1) for each power circuit.

jimbo36 · Post by **jimbo36** » Tue Aug 28, 2012 1:52 pm

Commissionpoint wrote:
Stripermann2 wrote:Unfortunetly, going around and just unplugging other boat's shore power is a no-no.
Says who? In my book keeping your property in a condition that damages my property is a "no-no". If you unplugging you keeps me and the rest of the dock from taking collateral damage consider yourself unplugged. If you continue to not make repairs and insist on plugging back in and causing more damage to others property you may find yourself without a shore power cord.

I'm not advocationg vandalism, steeling, or anything like that, but if somebody keeps doing something stupid and you are suffering damage to your own property as a result you have to take matters into your own hands sometimes.

Says who?

Well, if you unplug another boat you need to understand that you could be responsible for any problems that could result. For example, if you unplug a boat that is relying on the auto battery charger keeping the bilge pump active and the boat sinks causing several issues including invironmental, you may have a problem.

The owner may not realize there is a ground fault issue on their boat. At the very least, you will be shutting down refridgeration causing food to spoil and, heaven forbid, beer to go warm!

I strongly suggest you tell the marina operator and let them deal with the problem for you. By the way, when many boats are unplugged they need to be reset when plugged in again. Many Carvers are like this. I agree, premature deterioration of zinks needs to be checked out. Good luck.