galvanic isolator?

[furball]

I'm trying to find out if there is a galvanic isolator installed in our 2006 28TE. Sent a couple of emails to the facotry, but with the recent news, I don't figure I'll get an answer any time soon. Marine survey listed this as a "should do" item but my electronics guy seems to think a 2006 should have had one installed at the factory. Can anyone tell me what it is I'm looking for and where I may find it if there is one installed?
Thanks,
John

[jcollins]

Here's some information that may help explain it.

http://www.boatelectric.com/Galvanic%20Isolator.htm

[RicM]

There should be one on every boat that sits in salt water in a marina hooked to shore power 24/7. Obviously not every boat matches that description, so it's $150 that a manufacturer doesn't really have to spend. Easy to trace back to though. Follow the AC ground wire from the shore power inlet plug to the AC panel. If you don't find a rectangular box that looks like this:
http://www.starmarinedepot.com/detail.a ... _id=NE1041
and your boat matches the above description, you need one. Thankfully they are not too expensive and easy to install. I added one to my last boat and it cut down zinc erosion 75%. I plan on adding one to my Albin over the winter along with new electronics.

[Merry Kate]

Furball -

My 1997 28 TE came from the factory without a galvonic isolator installed and DID NOT have DC negative connected to AC ground!!! I certainly never had galvonic corrosion problems, but could have gotten killed. Bottom line is don't trust the factory to have done things right.

If you are handy with a multimeter there are tests you can do to determine if you have an isolator. Kind of complicated to explain here, but email me if you are interested.

Ed

[Pitou]

My Albin was not built with an isolator installed. At commissioning time this past spring, I installed an isolator. Oh what a difference in zinc loss.
I installed it under the cover board just down stream of the AC power plug inlet. The schematics of the Albin 28 AC system do not show an isolator, but that is not a guarantee that one has not been added by a previous owner or installed at the factory if the boat was built to order.

[furball]

Thanks for the info. Now I know what I'm looking for. I had a basic understanding of the purpose but I wasn't sure what it looked like. My web searches for a "galvanic insulator" weren't very fruitful. Plan to start tracing the AC ground tomorrow.
Ed, if I can't find one, I'll take you up on your offer, thanks.
I'm still in the process of picking my way through all the systems on this boat, one's that I've never had before.
Thanks again
John

[RicM]

Wonder why someone hasn't built one into a shore power cord, or a standalone that woul plug in before/after the cord?

[Mariner]

Wonder why someone hasn't built one into a shore power cord, or a standalone that woul plug in before/after the cord?

Because shorepower cords are already very expensive, and they get lost, stolen, broken, worn out, etc... Better to put the expensive equipment inside the boat where it's safe and protected.

Otherwise a good idea, though.

[Elizabeth Ann]

This topic was brought up again in another post: My Albin 28. Luckily for me b/c I didn't see it. I understand circuits and how sacrificial anodes (zincs) work. But I don't understand what/how a galvanic isolator does or helps.

Would someone like to save me some time and take a quick shot at explaining before I start searching wikipedia and the sort?


Cheers.

[RicM]

JCollins posted this link above:
http://www.boatelectric.com/Galvanic%20Isolator.htm
Executive summary:
For safety the ground wire in your shore power cord connects to all the other grounds from all the other boats creating a large extremely inefficient battery out of all the boats and the surrounding salt water. A galvanic isolator maintains the ground safety, but isolates your AC system from others, stopping the electrical erosion of your zincs.

[Elizabeth Ann]

Thanks Ric! the link you provided explains it too, my bad.

[RicM]

I'm a big promoter of GI's, they are relatively cheap ($150) reliable and save you money. Just follow the directions EXACTLY when installing and be safe, 120AC hurts!

[jms02050]

Hi. For folks who have installed a GI... I'm looking for more details. I've seen comments about installing under the cover boards. Not quite sure that means? The unit that I purchased, a Promariner FS30, won't fit in the space where the wire runs under the gunnel. In tracing the shore power wires I have 3 separate wires (w, b, g) in a bundle that disappear into a channel beside the water tank on the engine compartment side of the aft cabin bulkhead. I can!t relocate them after that. I was hoping to install the GI above the aft berth but I can't see how so I'm looking for options from those who've done this before.

Thx!

[Carl]

On my 06 flushdeck I was able to install it right next to the main breaker under the hatch on the same bulkhead.

[Pitou]

Hi. For folks who have installed a GI... I'm looking for more details. I've seen comments about installing under the cover boards. Not quite sure that means? The unit that I purchased, a Promariner FS30, won't fit in the space where the wire runs under the gunnel. In tracing the shore power wires I have 3 separate wires (w, b, g) in a bundle that disappear into a channel beside the water tank on the engine compartment side of the aft cabin bulkhead. I can!t relocate them after that. I was hoping to install the GI above the aft berth but I can't see how so I'm looking for options from those who've done this before. Thx!

By mounting under the cover board, we're referring to along the shore power inlet side up and along the same plane that the rod holders are installed on. On my 28, I installed my isolator just forward of the foremost rod holder and aft of the most aft bow railing stanchion. I accessed this area by removing the cockpit toe rail and then the ABS plastic rod holder insert. Once that was removed there was ample room to work. Be careful to not drill up through the fiberglass finish, plywood core and through the upper gel-coat. The plywood core is fairly thick. Absent of mounting in that location because that your isolator won't fit, I'd remove the cabinet containing the set of drawers below the companion seat in the pilot house and have a look around for where the wiring might go and a suitable mounting position for the isolator.