Shorepower short - help diagnose?

Only 2 pages and we've already begun the entertainment phase.

GregBrannon said:

Only 2 pages and we've already begun the entertainment phase.

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And this post only supports that.

Why are dissenting opinions "entertainment"...even if embellished a tad to keep things light?

Every boat should have an isolation transformer, especially if it is metal. You then get full shore power without a direct connection to the rest of the boat, all you are connecting to the dock is the transformer. This also protects swimmers and should help alleviate electrolysis between boats.

A damn good argument for throwing away power cords after submerging them or suspected damage. Maybe even toss it on a schedule? I'm off to buy a new one and use the old one for my welder.

As far as the rest of this thread goes, use the net to learn as much as you can and use your own common sense. Then discard half of what you are hearing.

Without any more information IMHO the most plausible cause is a corroded wire that increased its resistance. If a heavy load was present when the connection was made or there was a short circuit at the boat end of the cable, then the cable would heat and melt the insulation. At some point, then internally and without indication the insulation of the cable fails. Plugging the cable later then would cause the cable to heat significantly even though not enough amperage is being delivered to trip the pedestal over-current protection device.



This is one case where the entire cable should be replaced. Most probably, the marina pedestal has nothing to do with it.

rolomart3 said:

This is one case where the entire cable should be replaced. Most probably, the marina pedestal has nothing to do with it.

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I changed my Marinco cable without changing the inlet, and it fried again from water ingress. That shortcut cost me a new cord.

So I changed both to fix that, changed to Furrion for both. The inlet seems to better sealed than Marinco. BUT, the hole needed may be larger for the shroud back of the inlet unit, so measure first.

You're getting some advice but in my mind it isn't the right advice.

First, with the advice you are getting I didn't read that there is a change afoot to replace shore power pedestals to prevent drowning in marinas with people swimming where they shouldn't.

Second, it looked from the pictures that there is more going on than meets the eyes.

Third, a surveyor can point out some issues and if the damage is extensive your insurance company should cover it past your deductible.

Fourth, DO NOT and I repeat, DO NOT replace with the same crap that burned up. Look at the Smart Plug and get a Blue Seas ELCI installed in your boat, that's IN your boat by the wiring panel.

IF you think your boat and the safety of your crew is important the Smart Plug is the only way to go.

Good luck.
With the new pedestals the ELCI will help you to connect to those, there is a lower tolerance for differences in those and will also detect dock side, reverse polarity issues.

The smart plug is ONE, but not the only way to go.

Other options are 50A plugs that I find much less likely candidates for overheating by design and another option is direct wiring without a boatside plug..if that is an option and even better than smart plugs to a degree.

Plus there are othe manufacturers of ELCI and the packaged units are high priced for something you can connect in a waterproof project box inside your boat. Still not cheap but I easily shaved several hundred off the intetnet prices.

Carling probably makes the ELCI for many marine companies.

psneeld said:

The smart plug is ONE, but not the only way to go.
.

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Correct.

As an aside, a few months ago at a new municipal dock in BC, a US boater could not get his smart plug to match up with the pedestal outlet. Out of frustration he got several "connectors" from the marina to complete his connection. The bitching about all the money he spent on his smart plug that didn't work outside of WA State went on for awhile.

Post #36:

First, with the advice you are getting I didn't read that there is a change afoot to replace shore power pedestals to prevent drowning in marinas with people swimming where they shouldn't.

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I am not sure of your sentence structure but to be clear: There is a definite move towards the installation of a residual current devices or devices (RCD) between the service entrance to the marina or dwelling and the vessel. This started in 2011 and is codified in the National Electrical Code (NEC) and has been going through a state of flux as to where to place the RCD and at what trip level the RCD should be set at.

Post #38:

As an aside, a few months ago at a new municipal dock in BC, a US boater could not get his smart plug to match up with the pedestal outlet.

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I have been a SmartPlug proponent and dealer since they came on the market. The shore end of the SmartPlug manufactured marine cable is the standard Hubbell/Marinco twist lock. If he was using a SmartPlug manufactured RV cable, the shore end is the typical "dryer" plug.

At this time, SmartPlugs and their corresponding inlets are only made for the boat side of the shore power cable. They are coming out with a conversion kit for the pedestal in the near future.

IT is amazing that there are people who will try to save money in a place where safety should be the prime objective.

I saved a couple hundred making my own and who do you go after when your boat burns to the waterline? My boat is worth more than the money I might save making my own, cords included.

As to an issue with Smart Plug being used to connect to a dock side power receptacle, well there are those who have trouble tying their shoe laces.

I have used adapters to connect the twist lock end to a standard 3 prong extension cord I used to reach over 50' to a 20A shore side connection.

Have also used a regular shore cord to extend the Smart Plug cord so I can't imagine anyone having an issue connecting.

I have a Smart Plug on both 30A inlets and have cruised from the Chesapeake Bay up to Georgian Bay in Canada and NOT had any issues with connecting the male side to a power pedestal, both in marinas and also walls, which is a twist lock configuration.

Defender Marine sells Smart Plug, last I knew at a reduced price and with West Marine matching prices you could also save money getting yours there.

Please don't say one device is safer than another unless you have proof and an uncontested safety background.

No one is trying to save money over safety, some just don't believe the supetior claims of safety by smart plug in general, especially with the 50A plug design or over direct wiring.

Do what you like but don't profess to having the only answer when there is no proof it is.

While I have no EMPIRICAL proof, that is I didn't set up a lab and do all of the tests that could be anticipated with the Smart Plug, I think it is a safe & sound statement to profess the Smart Plug is a more secure plug on the boat side due to it's design.

I also think that it is safe to postulate that not all handy guys are handy in a strictly safe construction of a box or cord that does the same as a box or cord molded and manufactured by a company that specializes in product which MUST be built to more empirical standards than most handy guys can not achieve.

Therefore I felt it safe to state that building a box to save a couple hundred $$$ was not a safe idea (paraphrasing).

NEVER ran into or heard anyone who direct wired their shore power cord to their boat and it wouldn't be a far reach to say that from an electrical standard, the direct wiring could be subject to all of the moisture that is inherent around a boat. NOT something I would even contemplate.

As to the differences between a 30A to the 50A Smart Plug, the only difference is a 4th blade in the boat side connection. You can see from the picture attached that the plug is a more secure connection than the normal twist lock. I would think that would make it safer and provide less of a chance of arching which you get in the twist lock configuration and which is the major cause of fires on board.

Going on the basis that there are normally 2 types of shore side connections, a twist lock and the snap lock of the Smart Plug, the fact is that the snap lock with long blades making the connection is in fact a safer connection.

Reference an article (https://www.cruisingworld.com/smart-plug-safer-choice) from 2011 on the Smart Plug in Cruising World which references a safety inspection course for NOAA. Do a Google search for more about how much safer the Smart Plug is over the twist lock.

Notice, I intentionally left out a direct connections wiring to a boat since I can't think of anything more ridiculous. How would you put your cords away to protect them in winter or summer, if not in use?

In closing I think that there are plenty of people who try and save money over safety, BECAUSE they don't do any research on the safety aspect, they just don't see the merits of a professional job which cost money, whether it's in manufacturing or installations.

IMO.

I dont disagree with you or Cruising World on that 30A twist lock plugs are poor choices.

But i do disagree with people who have a tid bit or two of knowledge and say there is only one safe way to do anything.

The world proves that wrong every day.

50A twists and direct wiring such as in retractable systems are long proven safe if done correctly and maintained.

Plus Boatpoker on here (an accomplished surveyor) has posted about his direct wiring.

I made no suggestions for homemade anything.

Greetings,
Mr. N. "...a direct connections wiring to a boat since I can't think of anything more ridiculous" Hundreds, if not thousands of boats use this system which is hard wired to the boat. https://www.glendinningprods.com/wp-content/uploads/2018/01/cmb_v2.pdf


You have to get out more...

Interesting, I felt the same way, just didn't want to come right out and say it.

I guess even in the face of formative proof, some just can't accept. 50A Smart Plug is just as safe as 30A.

How many people in boats under 50' have a Glendinning connection. That's reaching to a great extent to TRY and make a point.

To each his own.

I think that until the standard connection to a dock is actually standardized or until a new standard is adopted, the so-called Smart Plug is another solution looking for a problem. The existing power cords are fine, keep them dry, no mechanical damage and use dielectric grease (or similar) on the plugs. Ergo bingo, no issues. Yank, dunk or improperly install a Marinco-type cable and all bets are off. Yes, there are marina fires but they are not bursting into flames all over the world due to these cables. Maintain yours as carefully as you obsess over your fuel/oil filters, oil type/anchor type and you will not have any problems.

Besides, $200+ for a boat-side plug only? Riiiight.

Mr N
The shore power receptacle in question, very new and built to Canadian regulations, is recessed and with a tight fit that accepts metal ends or those with a thinner rubber cover. This type of receptacle is not uncommon in BC. The owner of the vessel is pretty bright. You’d enjoy his company just like I do.

With the right knife, a trim job removing some orange rubber would have it working quite nicely. BTW, sales 101 says the customer is always right, no matter how dumb they may appear.

I just went out and bought a new 50' shore power cord, a Marinco. About $100 Canadian. It goes on the boat tomorrow and now I have a nice long extension cord.

Every boat owner on this site can afford to go and buy a replacement and treat it a lot better than you have been in the past and stop petting the sweaty things.

The number one way to destroy your shore power cord and possibly start a fire is overloading the shore power system. 30 amps is not very much power, 30 amps is 3600 watts if you are getting a full 120 volts.

One electrical heater is 1500 watts. A toaster is the same. Battery charger? Hot water tank? Alarm system? Electric blanket if you are sleeping onboard? CPAP? Cell charger? Indicator lights?

The best and easiest way to tell if you can plug in another heater or run the microwave is to stick your multimeter in a wall socket. If it shows 120 (or exactly the same as the shore power value) you are good to go, you are not overloading. If you are reading 112 volts or whatever value below system voltage, you are overloading your system. If you go outside and feel the plugs on your cord, or the cord itself, it will likely be warm. If you start the microwave and the meter goes to 90 volts, for example, not only can you fry electronics but you are severely overloading your system and your cord can overheat at a poorly maintained or suspect plug and the breaker will not pop! An overloaded system will cook the cord just like the pictures in the first post at best and start a fire at worst.

If you overload the system "slightly" and the cord heats over a longer time, arcing and pitting can occur at the plug, which will increase resistance even more and you will cook the plug or cord slower, perhaps when you have already gone home.

Smart plugs will not solve this problem, your use of the system and recognizing the very narrow limits of a 30 amp service will solve all shore cord problems.

Xsbank said:

The best and easiest way to tell if you can plug in another heater or run the microwave is to stick your multimeter in a wall socket. If it shows 120 (or exactly the same as the shore power value) you are good to go, you are not overloading. If you are reading 112 volts or whatever value below system voltage, you are overloading your system.

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...unless your shore power is 106 VAC to begin with. My marina is industrial power and it’s less than acceptable, and I’ve complained several times, got the Marina electricians to check it, BC hydro was onsite and they checked everything at the pole. They said it was the marina’s issue. Lots of finer pointing all around! And on it goes.

Jim

Greetings,
Mr. N. "That's reaching to a great extent to TRY and make a point." (post #42) Not at all. My point was made hard and fast. I saw NO stipulation of ANY boat sizes in ANY of your comments.



Now, IF you want to qualify your critical statements to boats UNDER 50', sure, I'll go along with that (except for my BIL's 44' Ocean sport fish with a Glendenning system but he doesn't really count does he?...because you've never heard of him)

RTF....it doesnt even have to be a Glendenning. Plenty of ways and boats where a power cord can be hooded directly to a main panel, etc. But they are a good example of a good way to protect the system.

Plus no one was questioning the safty of a %0A smart plug...not sure where that came from.

Again, thinking there is only one safe option for any boat system is short sighted in my experience.....and worse...trying to convince others that are just learning systems.

Guru,

I could not have said it any better. You are absolutely right. For every one operating hour of failure of these cables there are probably hundred of thousands of operating hours of use of the the 30Amp plugs without incident.
Having said that, we should respect the laws of mother nature. There is corrosion, erosion, and wear and tear.

Here is IMHO good advice:
I keep my boat safe by inspecting the blades of my 30 amp plugs every two months. I want to see the shinny metal in them and if corroded I file them. Then I reinsert the plug into the marina receptacle (or my own if using extensions) and twist it back and forth several times to scrub out any buildup in the receptacle.

I started this practice when I detected with a no contact thermometer high temperature in one of the 30 amp connectors at the pedestal. After cleaning the blades, the temperature was normal.

Also, every season is good practice to check the physical conditions of the insulation in the cables. It is possible to detect a leaky wire in a cable using a regular VOM tester. With the cable unplugged from everything, lay it down in the water except the connectors. Put VOM tester in ohms, and connect one lead to the water and the other lead to the hot, neutral and ground in sequence. The meter should not register anything (infinite ohms) if the cable is good. But this is not the end. The next test is the leakage test and requires to connect one test lead one of the wires hot, neutral or ground and the other to the other wires to test in pairs hot-neutral, hot-ground and ground-neutral. If there are no readings (infinite ohms), there is only one last test to declare the cable good. This last test I call it the "round-trip" test. It connects the test leads one at each end of the wire to do green-green, hot-hot, and neutral-neutral conductivity test. In this case the VOM should register zero ohms or a full needle deflection in an old analog tester) if the cable is good.

What about the connector? When they get bad most likely they will show burned marks. The integrity of the connector insulation may be checked after all the wire tests above have been performed. The test consist leaving the connector immersed in water for about ten minutes, drying its exterior with a hair dryer and performing the leakage wire tests indicated above.

If the connectors are not allowed to get wet, these checks should give you high confidence that there will be no problems with them.

Is this 100% guaranteed? Ah no. Remember there is Murphy's law and there is what I call Boater's Law.

Murphy's law says: "If anything can go wrong, it will"
Boater's law says: "Even if nothing can go wrong, something will"

Actually I DO think that 30camp plugs are a bad design and can be dangerous.

That's one reason I stepped up to a 50 amp service over 2 30s.

Too many times, I have barely bumped a 30A cord and it has either fallen out of the power pedestal or had a poor connection at either end. With living aboard and drawing higher amperage, it was never long before the 30A plugs showed signs of overgeating.

I would duggest stepping up to a smart plug if one has regular 30 A plugs.... OR a 50A circuit OR direct wiring.... as my main point was there ARE safe methods other than just smart plugs.

I currently have a 50A/120v plug on my boat. It is really solid. On my last boat, I converted the 30A inlet on the boat to a Smart Plug 30A inlet. I am convinced that it is a much better design, and therefore safer than the traditional 30A inlet. I am convinced only because I have had many years experience with the 30A twist lock connections. The Smart Plug connection is much more secure and that is why I make the assumption it is safer.

It also happens to be more convenient and easier to ensure a solid connection which is just an added plus. If my current boat had a 30A twist lock, I would change it to a Smart Plug.

Our 'new to us' boat has 50A 120 service also. But noticed the shore cord had a 50A 240 plug on the shore end, and a 50A 120 plug on the boat end - a big no-no. Changed shore end to 50A 125 (discovered old plug wires were corroded and breaking apart), and bought an expensive adapter for 50A 120 to 50A 240 for marina's that don't have 50A 120. Feel much safer now

JDCAVE said:

...unless your shore power is 106 VAC to begin with. My marina is industrial power and it’s less than acceptable, and I’ve complained several times, got the Marina electricians to check it, BC hydro was onsite and they checked everything at the pole. They said it was the marina’s issue. Lots of finer pointing all around! And on it goes.

Jim

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OR, the entire marina shore system is weak, when under load from a bunch of boats on the line drops the voltage, been to many like that.

FoxtrotCharlie said:

Our 'new to us' boat has 50A 120 service also. But noticed the shore cord had a 50A 240 plug on the shore end, and a 50A 120 plug on the boat end - a big no-no.

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Just curious but why would that be a big no no?


I would think that as long as just one leg of the 240 is wired with neutral and ground to the boat, then no harm no foul? I do not play a licensed electrician on TV.

what_barnacles said:

Just curious but why would that be a big no no?


I would think that as long as just one leg of the 240 is wired with neutral and ground to the boat, then no harm no foul? I do not play a licensed electrician on TV.

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Properly wired it should be what is normal and expected, otherwise it is going to be confusing. Which means a 240 volt single cord is not going to have a single 120 volt socket on the the other end. Sure it can work, I have not seen one myself, who knows, but maybe I would have done the same for expediency sake. I do also have a Y splitter myself that takes an incoming 50A 240vac and splits it out to twin 30 amp 120vac sockets..

I can see the concern over "jury rigging it", I was thinking more that maybe they just stuck a 240 plug on a 120 cable so they could plug it into the 240 pedestal.



Either way I understand the why on your part, thanks.

The "smart plug" system is expensive and found nowhere.

If a boat only needs 30A 120 onboard , by installing a 50A 120 plug and inlet socket on the existing cord it would be safe and parts , if required , found easily.

Any overload would be at the power pole end , so not endanger the boat.