Galvanic Isolator history

[Jeff_McKinney]

I was trolling through the archives and saw many posts on the topic of galvanic isolators. It looks as if the "older" boats did not have one originally. I'm curious if anyone can tell me when Catalina started putting galvanic isolators on the C34? I just got a copy of their booklet on the production techniques dated 3/28/06 and they specifically mention it being on all boats with AC power systems.

Thanks for your help.

[Ron Hill]

Jeff : I didn't know that Catalina ever installed galvanic isolators on ANY C34.  Why don't you call the factory and ask them the question and then inform us!!   

[Jeff_McKinney]

Ron,

I just called Leonore at Catalina, and she could not provide even an approximate date when the GI units started being installed. My boat was built in the latter half of 2005, so it'll be before then. I guess the obvious thing would be for folks to look at their breaker panels for a "Reverse Pollarity" light & test button on the AC side. 

This is probably one of those things that folks with a little too much free time ask (although I can't believe that our beloved Master Chief didn't have the answer either).

[Ron Hill]

Jeff : If you want to know the first hull# it was installed on, ask Gerry Douglas.  He knows as it costs $$ and a production line change!!  He's the only one (after Frank) that can make production line changes!!  My guess is that it was made with the beginning of a new model year!    

[Susan Ray]

I have a reverse polarity light that was an original installation... maybe you can pin down the date by replys from people with older boats.

[Jeff_McKinney]

Susan,

I wonder if it might have been a factory option "way back when". Your boart is older that Ron Hill's, and it seems he doesn't have one.

C'mon folks: help us expand our knowledge! Do you have a factory installed Galvanic Isolator? (be sure to mention your production year or hull number)

In the meantime I'll try Ron's suggestion & try to reach Gerry Douglas. Stay tuned.

[Craig Illman]

ok, I'll step into this......  my hull #1150 didn't have a factory galvanic isolator, it does now. I don't think a galvanic isolator eliminates the need for a reverse polarity light, I think you'd need to step up to an isolation transformer to achieve that.

Craig

[Stu Jackson]

The reverse polarity light has pretty much nothing to do with galvanic isolators or isolation transformers.  All the RP light does is check to see if the positive and neutral wires are crossed (or mis-wired) either on the boat or from shorepower.  A galvanic isolator is simply two diodes in parallel ONLY in the AC green ground wire, avoiding low levels (below and up to 1.0 volt) from leaking through the ground wire in an attempt to avoid current leaks to the water and protect nearby swimmers.  If there is a short, the diodes will allow current to flow through the ground wire back to the grounded shorepower.  An isolation transformer completely separates the incoming power to assure no galvanic corrosion; it is a transformer that does NOT change the voltage.  There is a complete "disconnect" between the shorepower and the boat AC, with the primary (shore side) being grounded to shorepower, and the boat ground on the secondary side of the transformer "may or may not be grounded on board.  Electrical leaks will not find a path through ground to the water."  The AC  ground on board can be brought to the DC ground, since it is separated from the shorepower.  The reverse polarity light is always a good thing to have on board and all boats should have one, to check the on board power wherever and whenever you may plug in to shorepower.  Also see the  discussion about reverse polarity lights related to generators, at:  http://c34.org/bbs/index.php?topic=2921.0

[Mike Vaccaro]

Charles Industries is now producing a line of relatively inexpensive isolation transformers (about 365-465 dollars, Defender Marine, depending on features).  An isolation transformer is the best piece of equipment to add to a baseline shore power system.  Traditionally, they have been heavy and expensive--thus most manufacturers have turned to galvanic isolators instead, even for metal boats.  ABYC Standards dictate that if a galvanic isolator is installed, it must be monitored.  This is not the case with an isolation transformer.  The down-side to an isloation transformer?  Size and hum (noise) produced.  The newest and most efficient 30 amp units still weigh about 60 lbs and occupy about a 10x10x10 space.  A less-than 400 dollar isolation transformer is a viable option when you compare the cost of a monitored galvanic isolator (about 300 dollars for a 30 amp unit), if you have space on-board for installation. 

Anything, however is better than nothing!  Even a non-monitored galvanic isolator (about 50-100 dollars for a bargin unit) is better than the original Catalina AC systems which connect the shorepower outlet directly to the AC distribution panel.  If your boat has a factory-installed isolator, great.  If not consider installing either an isolator or transformer. 

Cheers,

Mike

[steveg]

Gentlemen, I have a 2001 hull# 1572 and it came with a galvanic isolator from the factory.

[Jack Hutteball]

I have 2001 hull #1555 that has the isolator factory installed.