Pin and sleeve connectors for 30a shore power

[Cheechako]

My guess is the problem is really the size of the conductors/contacts in the twist OR the Smart version. It's one thing to say it's "30 amp" another thing to have it hold up to 15-20 amps on a near continual basis. Not to mention losses to contact reliability, (ie: metal resting against metal, but not attached securely to each other. There's always resistance in that situation)

When I lived aboard in Seattle I would go through a 30 amp cord about every 1.5 years. That's with one, or occasionally two small heaters, set to low 600 watt setting. So even if both were on all the time that would be a 10 amp draw. 1/3 of the rating for the cord. The old style Marinco boat socket outperformed the cords anyway..... although they go eventually also. My guess is the "Smart" is the wrong solution to the right problem.

I tried to put a new end fitting on a cord once, the copper in the cord was black for the entire length of the cord.

[hughespat57]

Originally Posted by Jammer

There have been substantial numbers of fires due to failure of twist-lock shore power connectors. Design wise, the connectors suffer from a small contact area, weak blades, and an ineffective primary locking mechanism.


Manufacturer "SmartPlug" offers a proprietary replacement that is relatively new to the market.


I would like to explore the idea that this is a solved problem. Industrial pin-and-sleeve connectors based on IEC 60309 have been in widespread use since about 1960. Larger versions are common for shore power service worldwide at 100 amps and above and for three phase service. The smaller 15/16a and 30/32a versions are in widespread use in Europe and the UK for dockside and RV (caravan) shore power connections, and for commercial, industrial, and food service equipment in wet areas.


For details, see: https://en.wikipedia.org/wiki/IEC_60309


Connectors and plugs are available at many price points; quality wise, you get what you pay for. But the contact area is much larger than that on twist locks, even on the less expensive devices, with better wiping action that tends to remove corrosion so it does not accumulate. The better ones are made with more use of high-temperature, fire-retardant resins.


I believe that the extensive installed base and field experience, including in marine environments, should provide greater confidence in these wiring devices than any newcomer to the market, no matter how well thought out on paper, should receive. They are also standards based and available from dozens of vendors worldwide rather than from a single source.



The 30 amp, 125v connector (pictured) is slightly larger than standard shore power connectors but will fit with minor modifications to the boat. I am thinking seriously about installing these on my boat during an upcoming power system upgrade.


Experiences? Thoughts?

I love my conversion from the 30A twist to pin and sleeve.
At the same time I upgraded to 50A service. I have an Express Cruiser Sea Ray 300DA, now a days much more power in use then back in the 1930s when that twist lock was introduced. I disassembled and nickle plated all the pins, they come apart easily.


The whole process is here
https://www.facebook.com/media/set/?...8211841&type=3

[sailingharry]

I have read through this discussion with interest.


All of my connections are the standard 30A twist lock. I frequently use a 12 gauge 100 ft household extension cord as my shore power, and so I have set my Victron Multiplus to limit shore power current to 15A. As a result, I have very little concern about overheating the 30A twistlock.


I agree wholeheartedly that the twist lock is not fit for purpose. But I have an unreasonable reaction to a proprietary replacement. The idea of supporting a device that can never be a standard just rubs me the wrong way.


And even changing just my shore power inlet presents huge challenges. I have two inlets, so I would have to change both. I have three shore power cords, one that stays on my dock, one that stays on the boat, and a spare. I can link more than one shore power cord together to reach distant pedestals. I have a couple adapters to allow my extension cord to plug into my shore power inlet. As much as I would love to upgrade, preferably to a legitimate standard, the cost and headache is mind numbing!

[s/v Jedi]

Originally Posted by sailingharry

I have read through this discussion with interest.


All of my connections are the standard 30A twist lock. I frequently use a 12 gauge 100 ft household extension cord as my shore power, and so I have set my Victron Multiplus to limit shore power current to 15A. As a result, I have very little concern about overheating the 30A twistlock.


I agree wholeheartedly that the twist lock is not fit for purpose. But I have an unreasonable reaction to a proprietary replacement. The idea of supporting a device that can never be a standard just rubs me the wrong way.


And even changing just my shore power inlet presents huge challenges. I have two inlets, so I would have to change both. I have three shore power cords, one that stays on my dock, one that stays on the boat, and a spare. I can link more than one shore power cord together to reach distant pedestals. I have a couple adapters to allow my extension cord to plug into my shore power inlet. As much as I would love to upgrade, preferably to a legitimate standard, the cost and headache is mind numbing!

You can simply go all Smartplug and then use an adapter to plug into a 50A outlet or even a 30A outlet if you like burning contacts

[Tudorsailor]

I changed from Hubbel to SmartPlug a few years ago. I am disappointed to see the photo in this thread of a SmartPlug that has burned at a pin

I have the boat-side connection permanently attached inside a deck locker. Should I leave it alone or should I remove it and coat the pins with something regularly?

[Dockhead]

Originally Posted by sailingharry

I have read through this discussion with interest.

All of my connections are the standard 30A twist lock. I frequently use a 12 gauge 100 ft household extension cord as my shore power, and so I have set my Victron Multiplus to limit shore power current to 15A. As a result, I have very little concern about overheating the 30A twistlock.

I agree wholeheartedly that the twist lock is not fit for purpose. But I have an unreasonable reaction to a proprietary replacement. The idea of supporting a device that can never be a standard just rubs me the wrong way.

And even changing just my shore power inlet presents huge challenges. I have two inlets, so I would have to change both. I have three shore power cords, one that stays on my dock, one that stays on the boat, and a spare. I can link more than one shore power cord together to reach distant pedestals. I have a couple adapters to allow my extension cord to plug into my shore power inlet. As much as I would love to upgrade, preferably to a legitimate standard, the cost and headache is mind numbing!

Derated to 15A, there is of course much less risk. That's what -- 1600 watts?


A much more challenging use case is those of us who use aircon and/or electric heating. I haven't been below 50N in my boat in years and I use electric heat almost year round when I have shore power (otherwise Eberspacher central hydronic), plus I heat water with a 1500 watt calorifier, and cook with induction. The Hubbell/Marinco connectors are simply not usable for this use case, even derated to 16-18 amps (which gives 3.6kW at our voltage).


However, I wouldn't leave the old connectors even with your use case. It's not that expensive or troublesome to swap them out for something decent.


The boat side doesn't care about standardization -- it's always your shore power cord plugging into it. The pedestal is a different problem, what concerns standardization, but one which doesn't present much risk to burning down your boat, unlike the boat side.

[Dockhead]

Originally Posted by Tudorsailor

I changed from Hubbel to SmartPlug a few years ago. I am disappointed to see the photo in this thread of a SmartPlug that has burned at a pin

I have the boat-side connection permanently attached inside a deck locker. Should I leave it alone or should I remove it and coat the pins with something regularly?

TIme will tell if that photo shows a freak accident or whether there are common problems with the Smartplugs. My guess is that burned one happened because one of the conductors was not screwed in tightly in during installation -- electrician forgot to cinch it down. Just a guess, but seems plausible to me. In any case, I've been using mine for 3 years now and there's not even any slightest discoloration of the pins, nor have any of my mates using them reported any problems. The design certainly LOOKS sound.

But if you can leave your shore cable attached permanently, why have a connector at all? Just hard wire it and Robert is your mother's brother. No connector will ever be as reliable as a well made permanent connection.

There was a time when I thought I might have a boat custom made in Holland, and I did a lot of work on the design brief. One of the points of the design brief was that there was to be a hard wired shore power cord which could be stored on a dry shelf in a deck locker, to be led out a special opening in the locker lid for connection. Far better like that, than having the connection removeable and outdoors, which is a significant design challenge.

This reminds me a bit of the issue with deck fillers for diesel tanks. Although 90% of all cruising boats have them, this inherently terrible design, the source of most fuel problems. Why put the filler with cap sealed by a single rubber o-ring, in a place where it can be immersed in green water? This is crazy. Bless Bill Dixon for designing my boat with the diesel filler well above deck level, in the side of the doghouse, and with a robust cap with gasket rather than flush cap with o-ring. After a lifetime of problems with diesel bug with different boats, I've never had a speck of anything in the tanks of this boat.

So if you can lead shore power into the boat from somewhere not subject to weather and water washing the deck -- you are way ahead of the game. And even more so if it is positioned so you don't have to use a connector.

[Dockhead]

For anyone who would prefer a standardized IEC, pin-and-sleeve, boat-side connector to the proprietary SmartPlug, here is a very good looking one:





Available here: https://www.svb24.com/en/shore-power...ess-steel.html


Much cheaper than SmartPlug, too, and produced by a big company which produces electrical power equipment for data centers.


I would not be using the 16a version, but they make a 32A, single phase version: https://www.ratio-electric.com/en/ar...eel-inlet-mp32


And waterproof! Looks like a very fine connector! I haven't used one of these or even seen one, so not recommending them, but surely worth investigating for someone looking to get rid of one of those twist-lock horror shows.

[nigel1]

Originally Posted by Dockhead

For anyone who would prefer a standardized IEC, pin-and-sleeve, boat-side connector to the proprietary SmartPlug, here is a very good looking one:


Attachment 272365


Available here: https://www.svb24.com/en/shore-power...ess-steel.html


Much cheaper than SmartPlug, too, and produced by a big company which produces electrical power equipment for data centers.



I would not be using the 16a version, but they make a 32A, single phase version: https://www.ratio-electric.com/en/ar...eel-inlet-mp32


And waterproof! Looks like a very fine connector! I haven't used one of these or even seen one, so not recommending them, but surely worth investigating for someone looking to get rid of one of those twist-lock horror shows.

I fitted the 32A Ratio about 3 years ago, very pleased with it, would certainly recommend it.
The inlet only accepts the Ratio manufactured plug, the standard IEC plugs wont fit.

[sailingharry]

Originally Posted by s/v Jedi

You can simply go all Smartplug and then use an adapter to plug into a 50A outlet or even a 30A outlet if you like burning contacts

The frustration is the quantity/price.
2 Inlets (combo is $213 each)

3 cord ends (one additional after 2 combos above at $102)

1 Smart-household adapter $205

1 smart-twist adapter, to allow daisy-chaining two cords $69
All in, about $800 plus labor. Ouch.



And all of this has to be done at one event. It can't be slowly converted. But all these issues are exactly the problem with changing ANY standard, be it to a proprietary newcomer, or a true standard.


The real problem with a proprietary approach is the cost. A 50' twist lock cord is $100. A 50' Smart cord is $350. That Smart-household adapter at $205 compares to the twistlock version at around $40. Some of that is because you get a better product. Most of that is because, well, there is no competition.


Again, my loads on my 30A cord are artificially limited to 15A (and normal loads are under 5A) so I'm not stressing it at all. If I actually used 30A, or even used 15A essentially continuously, I might have a different view.

[Nepidae]

Just for clarity's sake the safest shore side connectors are the SmartPlug.

Please see here (https://smartplug.com/) for specifics.

The 'special plug' is for the boat side.

The regular twist lock shore side plug is on the other end, so IF you've never seen that plug for the pedestal on the dock then you haven't boated much.

IT would really be nice for some to do some homework maybe BEFORE they comment. Links are also helpful to support what you are saying.

Change your wildly used Marinco boat receptacles to SmartPlugs with the SmartPlug cord. Great move for a better shore side connection.

[wingssail]

Originally Posted by Dockhead

This is not exactly data ("the plural of anecdote is not data" ), but for whatever it's worth, based on a lot of observations over decades since the early 90's -- anyone using shore power for any kind of serious load (aircon, electric heating) burns the twist connector in short order, even new ones, even fastidious owners. I used to keep a spare one on board at all times and replaced them every two years, and even then I often got burned contacts. In my experience, they are simply unfit for purpose. After switching to Smartplug, not the slightest hint of any scorch -- it's a great relief not to be worrying about that all the time.

I've had the same shore power cord on my yacht for over 30 years. It is Hubble 30A twist lock (both ends). My electrical usage is probably less than that of many of you, it maxes at about 400 kWh per month when the air conditioning is on. Much less the other six months of the year.

I have had to replace the boat end of my cord once, the boat receptacle once, and the shore end of my cord once. These replacements (not at the same time) were required because the plastic showed signs of overheating. Generally they do not get hot or even warm.

I watch these plugs constantly and, yes, I worry about them. But I don't think that they as big a worry as is being said. As long as the pedestals have twist lock/30A connectors as most do that I see, we are stuck with them. I could change the boat ends to pin and sleave, and might, but not high on my list.

[sailingharry]

Originally Posted by Nepidae

Just for clarity's sake the safest shore side connectors are the SmartPlug.

IT would really be nice for some to do some homework maybe BEFORE they comment. Links are also helpful to support what you are saying..

That is a very bold and unequivocal statement. Are there any third party/independent studies to support that? They are certainly good, but I'm not convinced about a blanket statement that they are "the safest."


And I also take issue with your comment about doing homework. This thread has been remarkably accurate. There are opinions, for sure. But unlike many threads, there has been very little unsupported or baseless statements (beyond your statement).

[Nepidae]

Compared to the 'standard' Marinco boat side receptacle and their cords the SmartPlug is the safest and to date I haven't seen anything else that comes close to the SmartPlug. I'm open if someone has a site reference for a better product.

Any boat to dock electrical setup has to have a 'normal' twist lock end for dockside and it sounded to me like someone was trying to equate the boat side plug of a SmartPlug cord to the shore side which they hadn't seen at any docks, duh.

The SmartPlug is a DIY setup as you remove the boat side receptacle, IF I remember, 2 screws to remove the wiring and 2 screws to remove the receptacle and slide the SmartPlug into the same hole, refasten the 2 screw to hold it in place and reattach the wiring. The wiring is the same so you unscrew it from the old receptacle, inside the boat and reattach the SmartPlug the same way.

The boat side cord plug snaps in, no twisting and the flanges are bigger for better contact. Shore side is the standard twist lock.

IF you got something better, please let me know.

I still stand by my research before pronouncing something wrong with a product, this isn't the 1st time I've seen this, and site references are always helpful.

[thinwater]

Originally Posted by Nepidae

Just for clarity's sake the safest shore side connectors are the SmartPlug.

Please see here (https://smartplug.com/) for specifics.

The 'special plug' is for the boat side.

The regular twist lock shore side plug is on the other end, so IF you've never seen that plug for the pedestal on the dock then you haven't boated much.

IT would really be nice for some to do some homework maybe BEFORE they comment. Links are also helpful to support what you are saying.

Change your wildly used Marinco boat receptacles to SmartPlugs with the SmartPlug cord. Great move for a better shore side connection.

Well, that was wildly (widely?) declarative manifesto about shore power (shoreside implies the pedestal end, which you do not own) connections.