Melt Down Anybody??

[RickB]

Do I have this correct - for 3X or so the cost of a 30 amp 110V Marinco I can buy a Smart plug with cord setup that requires the same care and attention?

Yeah, it's an old marketing tradition. Who says a product has to really have intrinsic value?

 

[Tom.B]

Hmmmm, seems to be some more posts suddenly vanished.

The original post was #48 and the follow-up was deleted by the author within the 1-hour edit window.

 

[Xsbank]

As a follow-up to my warm-cord question, I found this when I investigated. Fortunately I had a spare plug and this time it's all spooged with dielectric grease.

 

[Phil Fill]

ABYC recommends installing a double throw breaker right before the boat shore plug and after the main AC selector switch. So you have a breaker before the selector switch, before the boats shore power plug, and the dock shore power dock. Every year I disassembe, clean, and tight the plugs.

 

[Xsbank]

And this. Burnt wire and melted terminal structure.

 

[sbu22]

I hope to resuscitate this discussion with this seasoned audience. I couldn’t detect a clear consensus (not that I expected one) from the preceding and was wondering if there are any new developments or thoughts regarding the Smartplug.

I’m tired of fighting the Marinco twist plug fight. I have tried all the tricks (dielectric grease, taped plastic outer shields, etc., etc.) to protect and minimize corrosion on the connectors and still, persistently, wind up with scorched plastic at one or more of the connector pins within a year or so. As well as water in the feed end connector of the 50/30 splitter. In rereading the posts, I saw reference to CorrosionX – maybe I should give that a go.

I know plenty of supposedly salty boat owners that tell me “oh yeah, they do that, just use them until they crumble from the heat – I do that all of the time – no sweat”. Well, I do sweat.

The Smartplug looks like a much better design. The manufacturer info looks good and logical – but that’s how sales pieces are supposed to look. The Smartplug pricing is crazy, but on a life-cycle basis (if the Smartplug performs as advertised) I’ll come out way ahead at the rate I’m going.

I’m assuming that a scorched Marinco twist plug indicates it’s time to replace (and not just attempt to clean up the plug internals) the plug. Correct?

Any sage advice on the subject would be welcome.

 

[danderer]

I went to Smartplugs a couple years ago after having overheating problems with 2 traditional plugs. I installed 2 Smartplug sockets, purchased 1 new cable, and one end-fitting to retrofit to an existing cable (save money, right)?

Two years later I had an overheat in the Smartplug I retrofitted to the existing cable. Called Smartplug and they indicated 1) I probably hadn't properly seated the cable in their fitting correctly and 2) they had redesigned the retrofit plug to make this occurrence less likely. They also sent me a new 50' cable.

I've had no problems at all with their sockets or cables, but would not again try to reuse an existing cord with their system.

 

[Capt.Bill11]

You can use/change to whatever plug you want. But if the socket on the shore power post is bad it's not going to make much difference.

 

[Northern Spy]

You can use/change to whatever plug you want. But if the socket on the shore power post is bad it's not going to make much difference.

Why is that? Please explain.

 

[siestakey]

We have at least 5 at our Marina that have changed the boat owner bought the parts for the shore side and the marina installed I will keep everyone updated as to any problems

now it does not do them any good when at another marina

 

[FF]

One hassle is plugs and sockets come in a variety of quality .

Marinco is cheapo , Hubbel seems to last far longer.

 

[bayview]

none of those plugs will fail in a clean dry environment. Dirty or loose dock or boat connections are common as is dropping the cord in the water or allowing water to leak into the plugs. Don't allow the socket to take the strain of the cable.

I had marinco 240 50A cords attached to the boat in FL for 15 years and only replaced one plug though I did open, inspect, clean and grease all the plugs every few years.

 

[Capt.Bill11]

Why is that? Please explain.

If the shore receptical has corroded female receivers in it and/or the wire connections are bad you can still end up with a bad connection at your dock plug even if it's new. All a Smart Cord may do is give you a better connection at the boat. It can't really do anything more than a standard cord end can do about the dockside connection. And in my experience that is the end that is most likely to burn up.

 

[Northern Spy]

OK. I see what you are saying. My observation has been the problem is usually at the boat.

 

[bayview]

at either end people often allow strain on the connection. This is a cause of poor connections, loose sockets and burning of parts.

 

[psneeld]

pretty rare for the 50 Amp. 125/250 connectors....usually much beefier, aren't hanging by the tangs and obviously carry a much larger load easily.


That's why I went with them even if I don't use all the capacity most of the time.


Haven't seen nearly as many burnt 50A ones...a few ....but nearly none.

 

[SCOTTEDAVIS]

Yes. . a 30 amp, 50' cable with molded plug ends and a bulkhead receptacle is around $300. Look at Amazon.com

Down a bit here at 249

Shore Power Cords - Marine Electrical Connectors - Smart Plug Only 30 Amp Inlet & 50' Dual Config. Shore Cord



50' cord with factory ends is 140

Shore Power Cords - Marine Electrical Connectors - Smart Plug Only Smart Plug 50' Shore Cord 30 Amp

 

[SCOTTEDAVIS]

You can use/change to whatever plug you want. But if the socket on the shore power post is bad it's not going to make much difference.

A fire at the dock pedestal is better then a fire at my boat inlet.

I installed Smart Plugs on both of my 30Amp inlets (one for the house and one for the A/C's.

I had heat issues on the A/C inlet and connector, none after the change over, I sleep better. YMMV



I know it has been brought up but there are facts in this article regardless of your beliefs.

http://www.pbase.com/mainecruising/installing_a_smart_plug

 

[Capt.Bill11]

A fire at the dock pedestal is better then a fire at my boat inlet.

I installed Smart Plugs on both of my 30Amp inlets (one for the house and one for the A/C's.

I had heat issues on the A/C inlet and connector, none after the change over, I sleep better. YMMV



I know it has been brought up but there are facts in this article regardless of your beliefs.

Shore Power Cords - SmartPlug vs. 1938 Photo Gallery by Compass Marine How To at pbase.com

None of those facts change the fact that a Smart cord does little to correct any problems at the dock end.

And most of those burnt boat side connection issues could have been prevented by proper maintenance and replacement as needed.

But if you have to replace your boat side receptical and cord, getting a Smart Cord is probably the way to go. Especially if you practice minimal maintenance on your electrical systems.

 

[sbu22]

Bayview - couldn't agree more, but one of the problems is that water seems to always gets into the cable connection to the Y - suspended, strain relieved, locking rings cinched down - as far as I know I'm doing that correctly. But, when the time comes to disconnect - there's always water in the connection. This has been over a couple of sets of splitters and new plugs on the cable. I'm referring to marinco components with the plastic threaded locking rings.

Please expand on "grease" the plugs. I've used silicone grease on the plug tangs and the female plug apertures with the idea that the grease would be disrupted during connection sufficiently to allow electrical contact, with the non-contact surfaces protected from corrosion. Seems to work for a while, then back to scorching. Are we talking about the same thing?

 

[SCOTTEDAVIS]

None of those facts change the fact that a Smart cord does little to correct any problems at the dock end.

And most of those burnt boat side connection issues could have been prevented by proper maintenance and replacement as needed.

But if you have to replace your boat side receptical and cord, getting a Smart Cord is probably the way to go. Especially if you practice minimal maintenance on your electrical systems.

Smartplug is for your boats protection and is a better plug, more contact area for better current handling and due to it's better sealing and 4 point locking it has far less movement and corrosion and with that little heat production. This may mean less replacement in the future and may save money in the long run. The product is very well made and is much more robust then the old style in common use. I regularly saw 30^-40^ higher temp on my A/C side plug at the inlet before the installation of the smart plug and no increase above ambient after the change, good enough for me.

I did need to replace the inlet plug and cord anyway so the cost was less then a straight change out.

You are correct the dock side is going to remain what it is as I don't think marinas are going to change them anytime soon but like I said heat generated at the dock ped. and if a fire develops that is more the marinas problem then mine.

Really if a boater can't see the improvement in the design then how can one be expected to buy the correct anchor?

 

[sbu22]

Agree, Scottdavis. At least in my home slip, if the connection got bad enough to ignite, all there is surrounding is concrete and steel. Tempest in a teacup. And that's pretty much the case with the transient slips we use.

My primary concern is the boat side.

 

[Capt.Bill11]

Really if a boater can't see the improvement in the design then how can one be expected to buy the correct anchor?

 

[ghost]

The smart plug is a better product, but they have pulled the crud of accusing people of not retrofitting them to existing cables properly before. One of them was an electrician, they did not realize. Shame. The molded cord sets appear to be much better than the retrofit plugs.

I have not replaced mine in three years now. Used to replace marincos every year. Those are horrible.

It was not just the smart plug though. I also found ways to not run more than about 15 amps 20 max continuous. That more than anything else ensures my boat does not catch fire. It was a long journey to get there and a much longer story, but those are the key takeaways.

 

[psneeld]

I have for the last 7 years of living aboard run nearly the max (26 amps) through at least one 30 amp power cord for days/weeks on end and never notices any difference between that and the lighter use cord.


I suspect that it is not the amperage...just the probability that 30A cord ends are a really bad design, susceptible to easily loosening and corrosion. Combine those with high amperage and yes...burn marks....

For these reasons I have switched to the more robust 50A 125/250 ends...the bigger plugs don't just hand from the tangs and the increased capacity doesn't hurt.

Now for the real story. I have seen several cord end meltdowns...including one of my own at the power pole. I have seen maybe hundreds of blackened ends removed but many still in service.


Out of all of those, all gave pretty significant notice. Either blackened plugs or crackling sounds and hot ends. All were noticed with no fires....95% or better of the blackened plugs were long obvious before the meltdowns.


Of the several burning boats I have responded to, all were caused by internal wiring..not shore power cords.


I would be interested to see the stats on boat fires started by bad shore power plugs.


I think too many are a little paranoid about them...although replacing them regularly is expensive...I see most cords lasting at least 3 years, more closer to 5 and some much longer than that. My samplings is small...just mine, my friends and the boats around me at the marina. While I have read about electrical safety all the time in mags and online articles...I also never picked up on any epidemics on cords melting and starting fires considering how many are in use every day.

 

[SCOTTEDAVIS]

Now for the real story. I have seen several cord end meltdowns...including one of my own at the power pole. I have seen maybe hundreds of blackened ends removed but many still in service.

This is a very good reason to go with a product that is superior.

I want to not be one of the "hundreds" that have heat related failures and the accompanying fire risk.

Yes I am a bit paranoid regarding fire on a boat as opposed to the paranoia of the correct anchor. I have one way out of my stateroom and it requires me to transit pass the elect. panel and deck inlet location, fire would trap my wife and me below deck.

PS you posted a good argument for the installation of Smartplugs® at the next replacement cycle thank you for your service.


The reason for the heat is the very small contact area not lack of maintenance.

30A twist lock = 6.63 sq. mm total contact area
Smartplug® =190.4 sq mm total contact area

credit to http://www.pbase.com/mainecruising/installing_a_smart_plug&page=1


Anyone here using an anchor design from 1937?

 

[psneeld]

This is a very good reason to go with a product that is superior.

I want to not be one of the "hundreds" that have heat related failures and the accompanying fire risk.

PS posted a good argument for the installation of Smartplugs® at the next replacement cycle thank you for your service.

I did go with something superior... a 50A 125/250 plug.

Like you said about anchors...not everyone believes the new gen is all that much better....especially if you go big enough.

OK I will probably give you the smart plug is a better design. When I switched...it wasn't worth the extra money for the 1 in a bazillion chance I would have been worried about...


Coupled with the failure of some smart plugs and their lack of history...I can only suggest to newbies that fires from shore power plugs are almost non-existent ..otherwise the mag writing fearmongers would have smothered the mags with articles, insurance companies woud be screaming, the USCG probably would be saying something about it...and the hundreds of thousands of boaters out there would be flocking in droves to switch...none of the aforementioned is happening.

 

[SCOTTEDAVIS]

I did go with something superior... a 50A 125/250 plug.

Like you said about anchors...not everyone believes the new gen is all that much better....especially if you go big enough.

OK I will probably give you the smart plug is a better design. When I switched...it wasn't worth the extra money for the 1 in a bazillion chance I would have been worried about...


Coupled with the failure of some smart plugs and their lack of history...I can only suggest to newbies that fires from shore power plugs are almost non-existent ..otherwise the mag writing fearmongers would have smothered the mags with articles, insurance companies woud be screaming, the USCG probably would be saying something about it...and the hundreds of thousands of boaters out there would be flocking in droves to switch...none of the aforementioned is happening.

Two points

1. The fires caused by hot inlets are real and much higher then 1 in a bazillion, if you cant see the precursors of a fire after you stated you have seen several "melt down" and "hundreds" with early heat signs, well you're just silly.

2. The 50amp you changed to is no better as it has the same design and low contact area it is however larger so there is more meat to the contact area, as you are only running 30amp or less you have a larger safety margin. If you are drawing 240 volts through then the current load through the plug is lower reducing the heat load, but I suspect you are drawing 120 volts through the plug.

Look around PS it's a whole new world, sometimes progress is a real thing even if it's not in your wheel house.

 

[psneeld]

You are so wrong on both those points...especially calling me silly may make it three.


The 50A is a totally different design...just how it stays secure I believe is all it takes to be more effective than the 30A.


and where are your stats to prove me wrong staistically?


As I said..if the threat is so real...where is the public and governmental outcry?


I acknowledged that the smart plug is probably a better design...heck there are probably better EVERYTHING that was on my boat when I bought it and even after I replaced it all with 21st century stuff.


But a $5 Timex tells as good a time as a Rolex...it may not last a lifetime...but you get my point I am sure.


You will have the last laugh is my boat burns...I am betting my life it wont...at least not from the shore power cord.


Plus...all you ARE drawing through one of the 50A 125/250 plugs is 125V or so...2 times 110 to 125 volts per leg no matter what. I totally understand my setup...not sure you do.

 

[Capt.Bill11]

2. The 50amp you changed to is no better as it has the same design and low contact area it is however larger so there is more meat to the contact area, as you are only running 30amp or less you have a larger safety margin. If you are drawing 240 volts through then the current load through the plug is lower reducing the heat load, but I suspect you are drawing 120 volts through the plug.

FYI, a 240 50a cord is made up of two 120v legs. So no matter how you are using it, you are pulling 120v through the plug.