AC: ELCI vs. GFI outlets

marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
I'm looking at upgrading the double pole AC breaker on our 82 Catalina 27 with a real AC panel. I've only got three circuits: 2 AC outlets (already upgraded to GFCI) and the battery charger. I'm looking at the Blue Seas #8027 and #8101. The 8101 has ELCI ground fault protection built in, one fewer circuit (which doesn't matter to me), and costs more.

Is there a strong reason to get the 8101 and have ELCI protection, or are the GFI outlets (with the 8027) sufficient?

I'm also going to run new wire and put shrink sealed crimp fittings on all the connections.
 
KD3PC

KD3PC

.
Sep 25, 2008
1,069
boatless rainbow Callao, VA
If I were to do it today, I would spring for the ELCI...their trip current is a tad higher (30mils vs 5, IIRC) which keeps things sane in the tripping department (not as many false or nuisance trips perhaps) ..but the cost is a bit more as you have seen. Mounting in an existing location may require a deeper trim/expansion ring

Definitely tidy up the connections, as loose ones can add to the nuisance trips

btw, The Blue Seas gear is top line stuff.
 
B

Blitz

.
Jul 10, 2007
704
Seidelmann 34 Atlantic Highlands, NJ
The AC isolation panel for the back is a great idea and neat with blue seas
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
Bill Roosa said:
Why are you upgrading?
Click to expand
Right now there's just one main breaker for everything, so I can't turn off the charger and leave the AC outlets live. Trying to heat shrink the connectors when they are live is exciting...
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
KD3PC said:
If I were to do it today, I would spring for the ELCI...their trip current is a tad higher (30mils vs 5, IIRC) which keeps things sane in the tripping department (not as many false or nuisance trips perhaps) ..but the cost is a bit more as you have seen. Mounting in an existing location may require a deeper trim/expansion ring

Definitely tidy up the connections, as loose ones can add to the nuisance trips

btw, The Blue Seas gear is top line stuff.
Click to expand
Currently there's a plastic single gang box protecting the back of the breaker. I'll definitely use the Blue Seas back cover for this.
 
B

Benny17441

.
May 24, 2004
7,164
CC 30 South Florida
Have you considered just adding an On/Off switch to the battery charger circuit? A single pole breaker switch is quite adequate for your setup.
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
Benny17441 said:
Have you considered just adding an On/Off switch to the battery charger circuit? A single pole breaker switch is quite adequate for your setup.
Click to expand
That solves the switching problem for the charger, but I've still got 15A AC outlets protected by a 30A breaker. Certainly not the worst electrical setup in the boating world, but not that difficult to fix.
 
Maine Sail

Maine Sail

.
Feb 6, 1998
11,703
Canadian Sailcraft 36T Casco Bay, ME
An ELCI or RCD main breaker is like a GFCI for the whole boat. They are designed to trip at 30mA of leakage vs. 5mA in an effort to avoid nuisance trips... 30mA is still not much leakage just 0.03 amps. An ELCI will certainly expose any deficiencies in an AC system especially one that uses high load devices such as coffee makers, microwaves, hair dryers, air conditioners, larger battery chargers etc..

Be aware that ELCI's may not work with a portable generator because portable generators are not built or wired to marine standards. The current crop of ELCI's looks for a ground to neutral bond at the source/system and if not there they trip.

It is a very good idea to break your panel up as main breaker then branch circuit breakers for the load circuits. This is because you should not protect 14GA wire with a 30A breaker..

They are now a required device on new boat builds and I suspect eventually surveyors will be suggesting them in surveys. The launch of these devices has been anything but smooth but mostly because of the wide spread state of disrepair of US boats and our docks electrical systems...
 
tkanzler

tkanzler

.
Sep 5, 2007
689
MacGregor 26X Rochester
Maine Sail said:
The launch of these devices has been anything but smooth but mostly because of the wide spread state of disrepair of US boats and our docks electrical systems...
Click to expand
Some of that is intentional, as I understand it from my FIL. He tells me that, up until recently at least, it was common practice to cut the ground to the shore power cord. When he showed the video about in-water electrocution that was going around recently to his power squadron unit, all the old guys were surprised (he tells me - I wasn't there) because it was common practice to remove the ground.

It seems that what passed for 'common knowledge' in many circles was dangerously off. Mind you, most of these guys are just boaters, with lots of time in boats and on the water, but without formal training in boat and/or electrical systems. This kind of 'wisdom' gets passed from one to another, and what passes for common knowledge can kill you or others.
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
Chris Patterson said:
I've got to know, but WHY would anyone cut the ground?
Click to expand
If your boat has the AC and DC ground connected (which they should be, for safety) you are now connected by the AC ground to every other boat on your dock that is also plugged into AC. So your boat can become the "zinc" for other boats.

Here's a web page that describes it in better detail. http://www.yachtsurvey.com/corrosion_in_marinas.htm
It's a confusing topic and not many people understand it well. I'm an analytical chemist and I still have to think hard about it!!

Cutting the AC ground wire eliminates the stray corrosion, but makes it easy to electrocute someone in the water. A galvanic isolator, or isolation transformer is a much better solution.
 
tkanzler

tkanzler

.
Sep 5, 2007
689
MacGregor 26X Rochester
Chris Patterson said:
I've got to know, but WHY would anyone cut the ground?
Click to expand
I just spoke to my FIL, who said essentially the same thing as marchem above. It was to isolate your boat as a pathway for the 'stray current' leaked by other boats so it didn't become the sacrificial anode. He said it was common practice in his area some time back, and even some dealers would do it.

Just bringing it up because it's something I'd heard about in the past that I was reminded of in Maine Sail's original post, that should be looked into when buying a boat, or working on one you already own.
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
I read somewhere that an interesting test of your grounding system is to bring the end of your AC power cord that normally plugs into the dock close to your battery and measure the resistance from the battery ground to the plug ground. If you've got a galvanic isolator or isolation transformer this may not work.

While you've got the plug on the boat you can also measure resistance from the plug end to ground in the AC outlets on the boat. You may be surprised at how much resistance there is.
 
marchem

marchem

.
Nov 16, 2012
1,055
Catalina 310, 2000, #31 31 Santa Cruz
LloydB said:
lots i hope
Click to expand
Actually there should be very little resistance between the ground pin in the shore power plug and the ground socket in the AC receptacle. But most cords don't make a very good connection where they connect to the boat, or the wiring and/or connections are funky.
 
You must log in or register to reply here.

Top Bottom