Big Marina Rewire & the new code

[twistedtree]

Hmm so if you have a 240V load across the legs, phase will zero out the meter? Had never thought about or tried this... just seems counterintuitive because unlike neutral wire in a dual leg load there actually *is* net current flowing

There is definitely current flowing, but in equal and opposite directions, so it cancels out.

If you metered the wires individually, you would see the current. But when you bundle them together, it should cancel out to zero. If not, some current is following a path other than your shore cable, and that's a problem looking to happen.

 

[twistedtree]

It's great you got this resolved. I know it's a pain in the butt when you first discover problems like this, but they are real issues and all these RCD-equipped marinas will ultimately make boat electrical systems a bunch safer. It's just unfortunate that you can't easily test for this at your convenience rather than on arrival at a new marina after a long day....

 

[BandB]

It's just unfortunate that you can't easily test for this at your convenience rather than on arrival at a new marina after a long day....

But then, one can actually do so in advance of a problem.

 

[sunchaser]

But then, one can actually do so in advance of a problem.

Not really. A very good marine electrician tested my vessel and said we're good to go with new marina systems. But, upon arrival at new dock pedestals, tripping occurred. The answer, drop in a $$ big bulky IT. not quite ready for that.

 

[BandB]

Not really. A very good marine electrician tested my vessel and said we're good to go with new marina systems. But, upon arrival at new dock pedestals, tripping occurred. The answer, drop in a $$ big bulky IT. not quite ready for that.

Then I wouldn't call him "a very good marine electrician", at least not that time.

 

[seasalt007]

Then I wouldn't call him "a very good marine electrician", at least not that time.

I think the most important variable here is experience with the exact problem so that the very good ME knows what to look for at the git-go.

 

[BandB]

I think the most important variable here is experience with the exact problem so that the very good ME knows what to look for at the git-go.

Yes, there are many not up to date on their training and exposure.

It's a bit like going to a surgeon for a procedure. He tells you all about it and gives you the risks and percentages nationally to have issues. Then you ask him, "How many times have you performed the procedure and how many of those patients had problems?" He responds, "Oh, I've never done this exact procedure." You run.

 

[sunchaser]

I think the most important variable here is experience with the exact problem so that the very good ME knows what to look for at the git-go.

Bingo.

With no 30ma or more feedback it gets interesting. MEs not familiar with the nuances of the new dock (very few around in PNW except AK) setups become befuddled and move on to the next job. Dave Marchand said it best some posts ago, rather than chase ghosts, just install an IT.

 

[catalinajack]

" If the ground and neutral are bonded on the boat, I expect it would be in or around the main electrical panel.

This is what I recently discovered on our boat when poking around the back of the electrical panel for another purpose. I found a jumper in place between the main neutral and ground busbars. No longer. Before it's removal the return current through the green safety wire measured 6 amps. After removal the current was 5.23 mAmps, which is well below the 30 mAmp threshold that will trip an ELCI pedastal breaker. We have owned the boat for three years. No way of knowing when the jumper was installed or why.

 

[FF]

"No way of knowing when the jumper was installed or why."

The error usually comes with the addition of an inverter or perhaps the gen set.

 

[Ken E.]

Sales of isolation transformers is going to increase.

Ski, I'm going to install an IT based on what I've been reading. I haven't had a problem, but seems like a good preemptive thing to do. What's a good brand to buy? Same question for Dave Marchand.

 

[DavidM]

Ski, I'm going to install an IT based on what I've been reading. I haven't had a problem, but seems like a good preemptive thing to do. What's a good brand to buy? Same question for Dave Marchand.

Charles Industries are the guys to go to for isolation transformers.

David

 

[angus99]

Charles Industries are the guys to go to for isolation transformers.

David

Thought I'd read Charles was getting out of the marine business, but it appears standard isolation transformers will continue to be offered. Iso-boost transformers (like mine) are done for, however.

http://www.charlesindustries.com/Press_Releases/110216_MI MD Press Release.pdf

 

[sunchaser]

Jefferson Electric is another IT supplier.

 

[Cottontop]

This thread should be in the TF Hall of Fame.

What a great discussion.

 

[seasalt007]

This thread should be in the TF Hall of Fame.

What a great discussion.

But I still don't believe in electricity.

 

[rog]

this is it...

 

[seasalt007]

But wait, there's more.

The question: Could/Should a properly functioning and properly wired inverter trip a RCD breaker on the dock when one plugs into the dock without first turning the inverter off?

 

[psneeld]

Depends on the inverter.

My Pro Mariner has the ground and neutrals connected till you apply power through shore or genset.

When the pass through relay engages from external power, that connection is broken.

 

[O C Diver]

But wait, there's more.

The question: Could/Should a properly functioning and properly wired inverter trip a RCD breaker on the dock when one plugs into the dock without first turning the inverter off?

Simple answer is, mine doesn't. I have a Magnum Energy inverter / battery charger. It's always on either as the battery charger or as the inverter. It switches from inverter to charger when is senses shore power. Have not had a problem with it on the new docks at the Fort Pierce municipal marina.

Need to find some wood to touch. 5 or 6 weeks till the TF rendezvous and don't need to jinx myself.

Ted

 

[Comodave]

My boat would trip the GFI simply by plugging it in. It has 2 30 amp inlets. There was only 1 30 amp breaker originally. They had one of the 30 amp inlets wired directly to the supply bus bar. Also all the neutrals were tied to 1 bus bar. I replaced the main panel with a new Blue Seas that has the proper inlet breakers. It took several days to trace the neutrals out to see which should be on shore 1 and which should be on shore 2. After all this work it no longer trips the GFIs.

We did a friends boat. We found 4 major problems on his. Again all the neutrals were tied together, there was a neutral jumper from shore 1 voltage meter to the shore 2 voltage meter, the water heater had a short from ground to neutral and someone had replaced an outlet and swapped the ground and neutral. His boat does not trip a GFI now.

It is a pain but it does make the boats safer. My friend said he had been in the water between the boat and dock when his muscles locked up. Classic symptom of ESD. He was lucky that he was not in too deep water so he didn’t drown.

 

[MVCrossroads]

New to the Forum (although have lurked for years), as an EE and ABYC Electrician I wanted to add another twist to this tread. For those of you who have boats using a 50A/250V power cord and routinely use a smart Y adapter to pull from 2 30A/125V dock receptacles - this configuration will not work with ELCI breakers on the dock. The issue being the splitting of the neutral. You cannot control which side an electron returns. This wrinkle has been verified with engineers at Marinco/Mastervolt. Your two options are to plug into a 50A/250V receptacle or use a 50A/250V to 30A/125V adapter and only have use of one leg on your panel.

I hope this reduces some pain because some marinas new to ELCIs don't know this and will just assume you have a ground fault on your boat.

Barry

 

[seasalt007]

The question: Could/Should a properly functioning and properly wired inverter trip a RCD breaker on the dock when one plugs into the dock without first turning the inverter off?

I sent this question in an email to tech support at Magnum and got this answer.

**********************************
[FONT=&quot]No the inverter doesn’t need to be shut off before switching to shore power. Do so may mask a wiring problem but doesn’t solve the issues people may be having with tripping the RCD. With a properly wired boat, the RCD will not trip with the inverter in the on or off mode. The inverter is a break before it makes transfer relay and when it does transfer the inverter automatically goes to standby. The problem occurs when the boat is miss wired, there are few ways this happen. First is that they have a neutral to ground bond of the boat, you cannot have a permanent bond on a boat it must change with the source. This can happen as in the inverter using relays or with most generators and shore power by switching both the hot and neutral legs. The second and most common miss wire with an inverter is having the neutral input and output of the inverter common. The neutral in and neutral out of the inverter must be isolated, usually done by having an inverter subpanel. If they aren’t then the shore power is supplied to some load that have a neutral current path that my still be powered by the inverter until the transfer relay engages, which takes about 10 seconds to happen, which trips the RCD. [/FONT]

[FONT=&quot]Thanks,[/FONT]

[FONT=&quot]Darren Massey[/FONT]
[FONT=&quot]Sr. Product Support Technical Specialist[/FONT]
[FONT=&quot]Magnum Energy[/FONT]
[FONT=&quot]2211 West Casino Rd.[/FONT]
[FONT=&quot]Everett, WA 98204[/FONT]
[FONT=&quot]425-353-8833 ex:452 | F: 425-353-8390[/FONT]
[FONT=&quot]dmassey@sensata.com | www.magnumenergy.com[/FONT]

 

[aboatman]

While an isolation transformer will stop nuisance tripping of a shore power GFCI and help with corrosion issues, it's really a band aid. It's solving the symptoms, not the problem.

You should really find out why there is an imbalance of the power entering and leaving the boat. It could be something as simple (and safe) as the reverse polarity indicator circuit or it could be something serious that could shock or even electrocute you or a visitor or family member.

Personally, I was relieved last spring to be in a couple marinas with GFCIs on the docks and not have a problem. One had them at the power pedestals and one had them for each dock, meaning that a single boat with a ground fault problem would shut down power to about thirty boats.

That's a pretty poor design in my opinion especially considering that if it happened after the marina closed, power wouldn't be restored until the next day.

 

[seasalt007]

I had a good marine electrician out of Vero Beach on the boat today for almost four hours and he discovered a number of issues.

He stated that he had worked on about 40 boats in this marina for the problem since the rewire.

First he gave me an explanation for dummies of the new code in regards to current going to unintended places and why this will trip a new code breaker. In dummy terms (I refuse to believe in electricity at all. I just know it is there at the wall plug when I need it). For instance, let's say a boat receives 5 amps from the dock...it should return 5 amps to the dock. If it returns less then the difference has gone elsewhere. Perhaps to somewhere else on the boat and possibly found its way to the water around the boat. If the difference is over 30 milamp the breaker will trip.

What he found on my boat was that a few of the systems that were wired to always flow current through the inverter shared a connection with some systems that were not run by the inverter. He sorted these out. He also found that the refrigerator and icemaker and were wired incorrectly and he fixed these. Icemakers are a common cause of this problem...he said.

We are now sitting on the newly wired dock getting power.

The May 2018 issue of Power & Motoryacht has an article on this problem based upon the work of ABYC certificated electrician & master technician Michael Giannotti of Hartge Yacht Yard. This is the guy who fixed our boat when we were in Ft. Pierce last year.

 

[CharlieJ]

I would encourage anybody who wants to understand this problem in more depth to read this excellent blog post: https://wp.me/p30LrV-wT

Although most of the points have been covered in this thread, there are several salient points in the post.

 

[sdowney717]

I would encourage anybody who wants to understand this problem in more depth to read this excellent blog post: https://wp.me/p30LrV-wT

Although most of the points have been covered in this thread, there are several salient points in the post.

Good article to read.
On my own older boat, it has a Square-D panel. I swapped out four 20 amp normal breakers for GFCI-AFCI combo breakers on the hot water heater, Cruisair heat pump-AC, outlet circuits, kitchen circuits (MicroWave but NOT the fridge).

That leaves 3 circuits, the fridge, Princess stove, a forward, and aft electric heater without GFCI-AFCI breaker protection, and one unused circuit left in the panel.

That Square-D panel has twin 30 amp input with separate neutral busses for each incoming hot wire.

Those breakers will trip at 5 milliamps, far below a dockside 30 milliamp breaker. So far only had the outlet GFCI-AFCI breaker trip 3 times in the last few years, and may have happened after heavy rain, otherwise unknown nuisance trip reasons. But might be because too many outlets for that one GFCI-AFCI breaker.

I must have 20 outlets on that one 20 amp circuit running all over the boat. A couple extensions to the circuit to potentially wet areas, I plugged in extension cords running to a couple of fixed outlets, which can be easily unplugged to disconnect them if they get wet and would be continually tripping the gfci breaker.

I used to have a gen 1 galvanic isolator, before I installed the GFCI-AFCI breakers, one day I noticed it had failed. It burned up because a wire got wet in the cruisair connection box that runs the AC water pump, so it leaked enough current to kill it. Happened before I put in the GFCI-AFCI breakers.

TODAY, if a leakage current happened again, it would simply turn off the power to the Cruisair courtesy of the GFCI-AFCI breaker in my Square-D panel.

So very glad I never bought the gen 2 style isolator to replace it.

 

[DavidM]

I would encourage anybody who wants to understand this problem in more depth to read this excellent blog post: https://wp.me/p30LrV-wT

A very comprehensive discussion of the causes of ground faults. A little nerdy, and it takes some electrical background to understand it fully, but it is very well done and thought provoking.

David

 

[Tamrow]

A very comprehensive discussion of the causes of ground faults. A little nerdy, and it takes some electrical background to understand it fully, but it is very well done and thought out. https://gilwellbear.wordpress.com/2015/12/11/ground-faults-and-dockside-ground-fault-sensors/

David

From the quoted article, TOPIC: Galvanic isolators...
“Many boats are still fit with second generation Galvanic Isolators manufactured between approximately 2002 through approximately 2008. One such unit is the Professional Mariner (ProMariner) Prosafe 1”

I wish the electrician who worked on my boat a few years ago had read this article; it cost me several hundred dollars for him to trace the reason I was tripping the shore power pedestal breaker. When he found the reason he recommended I replace the Prosafe 1 with an updated ProMariner “Failsafe” galvanic isolator. I did and the problem was solved.

 

[CharlieJ]

This whole issue and the interaction between the boats' electrical systems and the "new" shore power system is very esoteric, even for an experienced marine electrician. That said, a good marine electrician will always start with the basics and work his/her way to the solution. As the support industry learn more and more about this complex interaction between the shore and vessel systems, troubleshooting should become less time consuming.