Breaker near the shore side power inlet.

[JDCAVE]

I made the mistake of mentioning to my surveyor that I intended to upgrade to the “Smart Plug” for my shore power. He said “That’s a great idea and while your at it replace the service to the panel as well!” Problem is he made it a requirement that this be done within the next 4 months of survey. Lesson learned: never, EVER, offer up low hanging fruit to your surveyor!

So why does AYBC call for a breaker within XX inches of the shore power inlet, when you have a breaker on the shore power pedestal and a breaker on the panel? Have any KK42 owners done this upgrade and if so, where did you locate the breaker? The shoreside power inlet is easily accessed inside the vessel by the access door behind washer/dryer units.

Jim

 

[DDW]

I'd guess that the breaker on the shoreside box is to protect the wiring in the box, plug, and cord to your boat. The breaker in your boat is to protect the wiring from it to the loads it feeds. These wires might be a different size with different capacity from the cord or shoreside box. Also, the shoreside breaker is of unknown age, quality and maintenance. A heck of a lot of boats don't have a breaker between the power in plug and the panel though.

 

[RT Firefly]

Greetings,
Mr, JD. Find a new surveyor unless it’s too late. We went through an insurance survey (required) four years ago and long, inane, story short, one of the “requirements” was the swim step brackets were rusty and MUST be painted. Good freaking grief!!!! Surface rust on a bracket? SERIOUSLY?

 

[Comodave]

I believe that ABYC recommendations are for a breaker within 10’ of the inlet on the boat measured along the wiring. It is to protect the wires in case of a short. Most boats do not have a breaker in between the inlet and the panel because the lenght of wiring is less than 10’.

 

[DavidM]

DDW is correct. A very common situation is to supply 30A power from one or two legs of a 240V 50A power pedestal with a Y adapter. In this case you can't rely on the power pedestal breaker to protect the boat's internal wiring as it is sized for 30A. Admittedly the shore power cord isn't protected at all in this situration.


The requirement for a main breaker within 10' of the shore power inlet has been in the ABYC standards for about 20 years. It is a bit of overkill IMO.


My last two Mainships, a 2003 Pilot 34 and a 2006 34T had these breakers even though for the Pilot it probably was less than 10' to the main panel breaker.



David

 

[sdowney717]

I put in 2 double pole breakers about 5 feet away from the power inlets, about 5 feet away from the main panel. And it is dumb, I think the idea is they want the boat owner to not hot plug the power into the inlet plugs which can cause arcing and wear them, they can get hot then cause a fire someday. So if the owner turns off the on boat breaker this is somehow better or more convenient than doing so on the dock? On the dock is always better! That de- energizes the supply cord. People are dumb clucks.

Thing to do, before you leave the slip ,turn it off on the dock, then when you come back, plug cord back into boat, and turn it back on at the dock power pedestal, if you have no dock pedestal, just unplug both power plug ends,on the shore cable. what do you think will happen if the shower cable falls into the water and the power is on at the power pedestal?
Well if not GFCI, you create a shock hazard and your power plug will burn up in salt water.

I do not know if the ELCI breakers in some power pedestals will turn off if the end of a shore cord falls into even salt water. Fresh water I doubt they will, but a gfci breaker will turn off if dropped in fresh water.

 

[High Wire]

If this applies you could use a marine double fuse block rather than a circuit breaker. Just make sure it is rated for the applicable voltage.



11.12.2.9.3. If the location of the main shore
power disconnect circuit breaker is in excess of 10 feet
(three meters) from the shore power inlet or the
electrical attachment point of a permanently installed
shore power cord, additional fuses or circuit breakers
shall be provided within 10 feet (three meters) of the
inlet or attachment point to the electrical system of the
boat. Measurement is made along the conductors.


11.12.2.9.3.1. If fuses are used in addition to the
main shore power disconnect circuit breaker, their
rating shall be such that the circuit breakers trip before
the fuses open the circuit, in the event of overload.
The ampere rating of the additional fuses or circuit
breaker shall not be greater than 125% of the rating of
the main shore power disconnect circuit breaker. For
120-volt service, both the grounded and ungrounded
current carrying conductors shall be provided with this
additional overcurrent protection.

 

[sdowney717]

If this applies you could use a marine double fuse block rather than a circuit breaker. Just make sure it is rated for the applicable voltage.



11.12.2.9.3. If the location of the main shore
power disconnect circuit breaker is in excess of 10 feet
(three meters) from the shore power inlet or the
electrical attachment point of a permanently installed
shore power cord, additional fuses or circuit breakers
shall be provided within 10 feet (three meters) of the
inlet or attachment point to the electrical system of the
boat. Measurement is made along the conductors.


11.12.2.9.3.1. If fuses are used in addition to the
main shore power disconnect circuit breaker, their
rating shall be such that the circuit breakers trip before
the fuses open the circuit, in the event of overload.
The ampere rating of the additional fuses or circuit
breaker shall not be greater than 125% of the rating of
the main shore power disconnect circuit breaker. For
120-volt service, both the grounded and ungrounded
current carrying conductors shall be provided with this
additional overcurrent protection.

breakers that trip before fuses, seems odd, what do they not trust the fuses to blow? If a fuse is rated at 30 amp, it will not blow at 30 amp, it will blow in a similar manner to a breaker at a higher amp depending on time duration of higher current flowing.
So if you have a 30 amp breaker you will need a 40 amp fuse to keep it from blowing and let the breaker trip first , but for a fuse, 30 amps times 1.25 is 37 amps not 40 amps, I do not see how the requirement can be met?

A 30 amp breaker takes a long time to trip at a significant overcurrent, a 30 amp fuse will blow before the 30 amp breaker will open. But a 40 amp fuse is way too high. In some of my testing on 20 amp breakers, it took 27 amps for a few minutes to eventually open the breaker.

 

[JDCAVE]

So I do have breakers on my panel, one for each shore power inlet and that’s pretty much within the 10’ minimum. Perhaps I was confused with the installation of the Charles Isolation Transformer, which requires this between the CIT and the shore power inlet?

 

[diver dave]

Fuses vs breakers. The basis of selection continues to amuse me. Nuke power plants and aerospace demand the highest reliability levels yet choose opposite solutions.
fuses in series with breakers in fairly close prox is something i have never seen. [emoji848]

 

[High Wire]

Fuses vs breakers. The basis of selection continues to amuse me. Nuke power plants and aerospace demand the highest reliability levels yet choose opposite solutions.
fuses in series with breakers in fairly close prox is something i have never seen. [emoji848]

If a nuke plant needs 37 amp fuses, they call up Bussman and have them made. It might cost $5000 for a box of ten but compared to a minute of outage time, that is cheap!

 

[diver dave]

Yeah. Well they did ask to see my equations for fuse coordination. Some of the fuse vendors graphs made it fairly hard to interpolate.

 

[CharlieJ]

In general, overcorrect protection devices (OCPD) are provided to protect the downstream conductors from overload, failure of the insulation and possible fire. Shore power pedestal circuit breakers are notoriously neglected and in reality may provide a false sense of protection. ABYC attempts to minimize this risk by minimizing (<10') the amount of conductor potentially unprotected if the pedestal breaker is faulty. It is that simple.

 

[sdowney717]

In general, overcorrect protection devices (OCPD) are provided to protect the downstream conductors from overload, failure of the insulation and possible fire. Shore power pedestal circuit breakers are notoriously neglected and in reality may provide a false sense of protection. ABYC attempts to minimize this risk by minimizing (<10') the amount of conductor potentially unprotected if the pedestal breaker is faulty. It is that simple.

Most people already have a main breaker in their boat distribution panel??
So they are protected.
This adding in another set of breakers is overkill, what now there are 3 sets of breakers?
One on the power pedestal, one or two in the wire running to the boat distribution panel and one or two in the boat distribution panel.
Maybe they like breakers, or maybe a marine breaker company got them to agree so they can sell more breakers.
I don't know, but for decades boats were considered appliances plugged into the power with a temporary cord, just like an appliance at your house.

My boat built in 1970 survived without anything happening, I think most boats were fine with things they way they were.

I had one issue a few years ago, the cord got damaged, maybe pinched and it was in the water. The pedestal breaker did not trip, not enough current flow and not enough leakage for an ELCI to blow open, so the cord was consumed about 6 feet of copper wire in a couple of says by the current leaking-shorting into the water, it was arcing in the water inside the cord from hot to neutral.

Only a GFCI could have stopped the current flow. Regular or ELCI breaker was worthless.

 

[diver dave]

Charlie is correct on the OCP purpose. But ask yourself how many feet of hidden flaming conductors u r willing to find acceptable. I feel 10 feet is far too many. In a home, that length of unfused interior service needs steel pipe or 2” of concrete around those conductors.

 

[sdowney717]

Charlie is correct on the OCP purpose. But ask yourself how many feet of hidden flaming conductors u r willing to find acceptable. I feel 10 feet is far too many. In a home, that length of unfused interior service needs steel pipe or 2” of concrete around those conductors.

How is it unfused??
where is it unfused??
Your assuming the dock pedestal breaker is worthless and doesn't even exist..

Logically, you should carry around a fused or breakered extension cord then for every single thing you plug in anywhere, or your not being consistent.

 

[diver dave]

One of the issues is this use of 2x 30 amp y’s into a dock recept that is breakered at 50 a upstream. U have #10 awg inside the boat protected by 50a “trustme” breaker.

 

[Ski in NC]

So to comply you put a breaker in a box in the cockpit where you get all sorts of sea spray , splash and rain. Yep you put it in a sealed box but twice I have seen those boxes burned up.

No where else have I seen where a properly sized conductor had to have a breaker in the middle of the run. Can't see the sense in it. I've got about 18' from shore connector to panel 30 2pole breaker.

 

[DDW]

Well one thing is that the 18' of shore power cord is outside the boat. The 10' of wire inside is buried from view, possibly hard pressed against flammables, and likely rarely/never inspected for chafe or wear. It's a belt and suspenders thing, not necessary unless it's your boat that catches fire.

Personally I'd be more worried about other things, but the ABYC is paid to worry.

 

[diver dave]

So to comply you put a breaker in a box in the cockpit where you get all sorts of sea spray , splash and rain. Yep you put it in a sealed box but twice I have seen those boxes burned up.

No where else have I seen where a properly sized conductor had to have a breaker in the middle of the run. Can't see the sense in it. I've got about 18' from shore connector to panel 30 2pole breaker.

I would agree. YOU dont need this, but how many boats in the marina have 10awg protected by a 50a breaker?

The industry needs a wakeup call. Y adapters and 208 volts ?

 

[CharlieJ]

Post #14
Please read and understand this sentence:

Shore power pedestal circuit breakers are notoriously neglected and in reality may provide a false sense of protection.

As I stated in Post #13, which simply stated the facts, ABYC is concerned with the wiring from the shore power inlet to the panel board that may not be protected if the "notoriously neglected" pedestal circuit breakers have a diminished capacity to react to a phase to ground fault.

Post #14
You do understand that the primary difference between a standard GFCi and an ELCI is that a GFCI will trip with 6 mAAC of leakage and an ELCI requires 30mAAC of leakage so what you are reporting has an element of disbelief associated with it.

Post#14

Maybe they like breakers, or maybe a marine breaker company got them to agree so they can sell more breakers.

That's pretty insulting to the 300 volunteers that produce the ABYC Standards. Believe me, there is no way that a "...marine breaker company..." could influence the Standards to favor their product. The system just does not work that way.

A secondary, but very, very real issue is the 50A > 2 x 30A adapters in wide usage that Diver Dave points out. A properly sized auxiliary circuit breaker on board may well save a boat if a fault develops.

Post #18
No, the Standard does not call for

So to comply you put a breaker in a box in the cockpit where you get all sorts of sea spray , splash and rain.

That would be just bad judgement.

 

[CMS]

The requirement for a main breaker within 10' of the shore power inlet has been in the ABYC standards for about 20 years. It is a bit of overkill IMO.

Customer Question:
“RC my surveyor failed our boat because the distance between the AC inlet and the Main AC breaker is more than 10′, this seems stupid. Can you write a letter to my insurer for me explaining why this is not required on an older boat?”


Answer:
“No!”


Here’s the scenario for the image below:

• 30A on-board Main AC breaker
• Big production boat builder
• Breaker was approx 19 wire-feet away from the shore power inlet
• AC inlet feed wire was not in conduit or even a chase
• Boat plugged into a 50A 120V service via a 50A to 30A “adapter”
• Dock pedestal protected by a single pole 50A breaker
• 12GA wire (not compliant for 30A service) feeding the on-board 30A Main AC breaker
• Vibration & chafe created dead short in the 19′ of unprotected wire before the Main AC breaker.

The image below is a prime example of why the ABYC suggests a main AC circuit breaker to be within 10′ wire feet of the shore power inlet.



I personally prefer to see a breaker or preferably a main ELCI breaker immediately after the shore power inlet. As one who works on marine electrical systems for a living I believe the 10' rule is far too generous, based on the pathetic excuses for marine wiring I get to see every day.

 

[CMS]

Your assuming the dock pedestal breaker is worthless and doesn't even exist..

Not totally assuming anything, the standards are very often based on actual events that lead to the creation of the standards.



I can't even begin to count the number of mis-wired pedestals I have seen, and this is in Maine were we have very few marina's. It is not entirely uncommon to see a pedestal breaker that has been by-passed entirely, after Muffy & Skippy left the dock with the shore cord still attached and the marina sent Daryl & Daryl down to "fix it", as opposed to an actual electrician. I've seen 30A pedestal receptacles protected by single pole 50A breakers, breakers bypassed entirely, inoperable breakers, likely due to corrosion, hot and neutral reversed in the pedestal etc. etc..

Marina wiring, historically speaking, has been extremely unreliable, hence the standards for the boat side which are there protect from what the boat owner has no control over, shoddy marina wiring.

 

[sdowney717]

The breaker only protects wire downstream of the breaker.
Anything before the breaker, see in this case will be all the wire running back to the shore power inlets, then the soft shore power cord and back to the dock pedestal with it's 'worthless miswired' breaker is if you believe some people, totally unprotected. So if it is worthless and unprotected, then liable to catch fire too. So your middle of the wire breaker added into the boat system wont do a thing to help you, unless your buried highly protected insulated wire feeding you boat distribution panel decides to fail.

I feed my boat distribution panel with an 8 gauge wire, the breakers are 30 amps. So even forgetting about the inbuilt safety factor of 10 gauge wire how it is officially approved for 30 amp usage, my system can not overheat and cause a fire. I am susceptible to shore power cord woes, even with a good pedestal breaker, simply cause it is out in the exposed environment and could get physically crushed. And that is the only failure I have had.

Other thing, since law now mandates ELCI breakers on the pedestal, miswiring will be a lot harder to accomplish, as those breakers self test.

IMO, they should have gone with GFCI not ELCI, GFCI protects your life, ELCI will still kill you. I run my boat panel with GFCI and it is almost perfect, do get an occasional nuisance trip. All my circuits are GFCI-AFCI combo breaker protected except for the stove and fridge, I left those out. I hardly ever use the stove. The fridge I deliberately left out of GFCI protection as a nuisance trip would be really bad. You will never find an ELCI breaker in or around your home, and for good reasons.

 

[dhays]

Interesting thread. My last sailboat, a 2005 Catalina 400, had a stern AC inlet and it was over 10’ from the main panel. It had a breaker mounted about 4’ from the AC inlet. It tripped once and it took me a while to remember where to find the breaker.

My current boat has two AC inlets. The primary one I use is located on the side of the PH and is about 6 wire feet from the circuit breaker on the AC panel. However, it also has a AC inlet in the stern. I’ve never noticed a circuit breaker for that inlet. I’m guessing there may be one so I’m going to have to start digging.

 

[psneeld]

My friend has a 42 Catalina with transom mounted power inlets with breakers just inside.

2X in the last couple years he has had the power cord weld itself inside the inlet and no breakers anywhere popped.and the cord ends were charcoaled.

There is a lot to be said about minimizing recetacles and connections aboard a boat....

I wired in an ELCI just inside my shore power inlet, but that was more for the ELCI than the 6 foot or so tun to the main panel.

 

[dhays]

My friend has a 42 Catalina with transom mounted power inlets with breakers just inside.

2X in the last couple years he has had the power cord weld itself inside the inlet and no breakers anywhere popped.and the cord ends were charcoaled.

There is a lot to be said about minimizing recetacles and connections aboard a boat....

I wired in an ELCI just inside my shore power inlet, but that was more for the ELCI than the 6 foot or so tun to the main panel.

One of the first things I did on my Catalina when I bought it (2005 boat I purchased in 2010) was to swap out the 30amp power inlet with a SmartPlug inlet.

In my case the 30 amp breaker had tripped because I was drawing more than 30amps of power. The breaker near the inlet tripped before the breaker at the panel.

 

[CharlieJ]

My friend has a 42 Catalina with transom mounted power inlets with breakers just inside.

2X in the last couple years he has had the power cord weld itself inside the inlet and no breakers anywhere popped.and the cord ends were charcoaled.

The explanation for this condition is that there was a high resistance contact in the plug/inlet interface where enough heat was generated that the plug "charcoaled". This occurs at < trip point of any upstream circuit breakers. I see this in my business about four times a year and have a box full of failed plugs and inlets to show and tell. SmartPlug eliminates this problem.
Full disclosure: I am a SmartPlug dealer

 

[psneeld]

I know the reason and the poor placement of the inlets and overall design.

High resistance connections are why I dislike every unecessary break in a continuous run.

Reasonable arguements can be made for and against added "protection" when it introduces a possible failure point.

 

[JDCAVE]

Thanks all for your comments and CMS and CharlieJ for describing why a breaker after the shore power inlet is a good idea. I think I will proceed with install the breaker in the near future at the time when the Charles Isolation transformer is installed. Note: I believe the CIT instructions do call for a breaker prior to the CIT.


I have just replaced the shore power inlet in the boat with a Smartplug receptacle. The green ground wire was the typical tinned, (8 gauge?) wire, but the black and white wires were untinned copper, with the “strands” being very coarse diameter. These wires are not very flexible. Would these be the so-called welding cables that were used on similar vintage KK42’s? It seems to me that surveyor’s recommendation to replace the service all the way to the panel makes sense in this case.

Question: the easiest option for me would be to locate the breaker box on the other side FRP molded structure where the shore-power inlet is located. Is it acceptable to afix this box with an adhesive such as 4200 or 5200?

Question: the second 30 amp Inlet is of unknown function. It does go the the panels as evidenced by a lit LED, but does not seem to power anything. Is this a provision for a possible air conditioning install?

Jim