Smart plug melt down

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
GoneFarrell said:
What I've seen too many times is that the plugs are at an angle in the sockets due to weight of wire or getting tugged as the boat moves in moorage.

The misalignment means poor contact, heat, then the smoke gets let out of the wire and connectors.
Click to expand...

A lock ring will prevent that from occurring.
 
Xsbank said:
By the way you Glendinning users, I'm sure you are aware how a toaster works, with coils to produce heat? Guess what you have on that spool if you don't unroll the entire cable when you plug it in? Same reason why you never use an extension cord that is still coiled. In your case, the breaker should be installed right at the cable-winding thing.
Click to expand...

I am certainly not an electrical engineer and would never claim to be savvy about the physics of it. My understanding of the toaster coil thermodynamics was that there was simply more glowing wire in the same linear distance. But if the cable isn't overheating, why would it being coiled cause a problem? Is it relying on air cooling somehow to keep from melting? I wasn't aware of that.

This boat is 20 years old. I know that for at least 12 of that, it had about a third of the cable out. In Florida, running the AC 24x7. Why isn't the cable even discolored? Why didn't this cause a problem? I'm not doubting, just trying to understand this better.
BD
 
syjos said:
A lock ring will prevent that from occurring.
Click to expand...

I agree, and that's what I use on Imagine, along with fair routing/support of the cable.

Nonetheless, this occurrence is too easy to find when I'm walking the docks. I'm thinking I should check some of these on my dock pedestals, as I'm at the end of the dock. I only have to prevent one dock fire. Our security guys won't do it. But we did have an electrician thru recently who checked out the dockside stuff for loads and leakage. Too easy to take this stuff for granted.
 
Xsbank's comment got me concerned enough to go review my manual from Glendinning. I figured if this was a concern then surely there would be warnings about it - they sell a lot of these and don't want lawsuits or boats burning up. Admittedly I didn't read that manual closely. I figured there was in and there was out - what else did I need to know?

There's nothing in the manual about extending the cord any amount, although there are numerous other warnings. In fact the only statement related to this is where they say "In actual usage of your Cablemaster, you will find that the power cable is seldom payed out completely. Because of this, it is advisable to occasionally pay out the cable completely and allow the cable to recoil into its natural coil.

It seems expected that it's not payed out. I'm not going to worry about it anymore.
BD
 
Having the cable partly coiled will cause it to run a bit warmer. That's why there are bundling derates for wire. I'd just monitor the temperature in warm weather and if the coiled cable isn't getting too warm, then it's not an issue.
 
GoneFarrell said:
What I've seen too many times is that the plugs are at an angle in the sockets due to weight of wire or getting tugged as the boat moves in moorage.

The misalignment means poor contact, heat, then the smoke gets let out of the wire and connectors.
Click to expand...

Upgraded to 50A 125/250 service and use one of these. Solid as a rock connection.

Not worried at all.
 

Attachments

  • 338298-25474.jpg
    338298-25474.jpg
    9.8 KB · Views: 102
Last edited:
rslifkin said:
I'd just monitor the temperature in warm weather.
Click to expand...

This is much more critical in cold weather with most liveaboards such as the OP running al lot of electrical heaters. Many appear to think you can run a 30amp cord at 30amps indefinitely.
 
boatpoker said:
This is much more critical in cold weather with most liveaboards such as the OP running al lot of electrical heaters. Many appear to think you can run a 30amp cord at 30amps indefinitely.
Click to expand...


Good point on power draws being higher in cold weather. I was thinking of the warm weather / heavy load (lots of A/C or something) case as being worst, as in warmer weather, the cord will be warmer for a given load (not relative to ambient, but in absolute terms).
 
Y'all may have missed one of his points in the video. He stated that the shrink wrap was pushing on the cable and that the weight of the cable was hanging on the plug. The weight could have done it alone, but add to that the pressure applied to the plug in a downward direction and water dripping from above (he mentioned the condensation) and it would easily allow water to drip in alone the top between the plug and the outlet. It isn't hard to figure out what happened and it is something he should have corrected. Honestly, no matter what, the inlet plug should never be difficult to reach and should be checked regularly. This was his real mistake... letting the shrink wrap and the "bridge" that was built from the boat to the shore, interfere with access to the plug and apply any pressure to the plugs.
 
Current flowing in a cable generates heat. This causes the temperature of the conductors to rise until the heat lost balances the heat generated. If the temperature gets too high the insulation on the cable softens and eventually melts.

When you pack lots of cables that are all carrying current (whether multiple seperate cables or multiple loops of the same cable) together heat dissipation suffers resulting in a higher temperature at a given current. This is most relevant to 50 amp connections.

Reels are particulally bad because they tightly pack together a large number of passes of the cable. Excess cable in a loose jumble on the ground is far less likely to overheat than excess cable wound tightly on a reel.

You get away with it most of the time because most of the loads people plug into leads are small and/or intermittent. From time to time though the right combination of circumstances come together and melts one. As we are talking about the propensity of boaters to overload, I still think that the coil-type should be extended fully.

Also, if you have an electrical code book, read the bit about multiple conductors and derating. That should give you an idea of the max current a given cable can carry.

I didn't watch the video so for my comments, it's irrelevant. Try and list all of services you are powering when you hook up shore power and remember that about 3000 watts is the continuous maximum:

Battery charger
Isolation transformer
Galvanic isolator
One or more heaters
Lights
Device chargers including wired USB ports
Alarm systems
Water heater
A/C
Freezers
Ice maker
Water pumps
Electric heads
Numerous kitchen appliances
Inverter
Electrical system monitors
There's more.

I would be willing to bet that a normally maintained shore power cable will perform as designed if its designed load is maintained. As soon as you exceed that parameter, you are putting yourself and others in peril.
 
Last edited:
Xsbank said:
Current flowing in a cable generates heat. This causes the temperature of the conductors to rise until the heat lost balances the heat generated. If the temperature gets too high the insulation on the cable softens and eventually melts.

When you pack lots of cables that are all carrying current (whether multiple seperate cables or multiple loops of the same cable) together heat dissipation suffers resulting in a higher temperature at a given current. This is most relevant to 50 amp connections.

Reels are particulally bad because they tightly pack together a large number of passes of the cable. Excess cable in a loose jumble on the ground is far less likely to overheat than excess cable wound tightly on a reel.

You get away with it most of the time because most of the loads people plug into leads are small and/or intermittent. From time to time though the right combination of circumstances come together and melts one. As we are talking about the propensity of boaters to overload, I still think that the coil-type should be extended fully.

Also, if you have an electrical code book, read the bit about multiple conductors and derating. That should give you an idea of the max current a given cable can carry.

I didn't watch the video so for my comments, it's irrelevant. Try and list all of services you are powering when you hook up shore power and remember that about 3000 watts is the continuous maximum:

Battery charger
Isolation transformer
Galvanic isolator
One or more heaters
Lights
Device chargers including wired USB ports
Alarm systems
Water heater
A/C
Freezers
Ice maker
Water pumps
Electric heads
Numerous kitchen appliances
Inverter
Electrical system monitors
There's more.

I would be willing to bet that a normally maintained shore power cable will perform as designed if its designed load is maintained. As soon as you exceed that parameter, you are putting yourself and others in peril.
Click to expand...

What he said .
 
catalinajack said:
But, I finally tired of manhandling that old, stiff cold - my wife couldn't at all - and purchased a factory-made Smart Plug cordset. It was one of the wisest boat equipment purchases I ever made. The cord jacket is some kind of silicone rubber, is lighter weight, and remaines flexible in even very cold weather. My wife is able to coil it whereas it was impossible with the other cordset.
Click to expand...

I didn't know the SmartPlug cord was more flexible and lighter. That makes it more interesting. I don't have space for a Glendenning so like anything that makes the cord longer lasting, easier to drag and especially easier to coil.
 
O C Diver said:
While you never know what the real story is, here is my take. What we know for certain is two 30 amp shore power cords were connected through a Y connector to 50 amp service. We also know the Smart Plug cooked off. Beyond that we don't know if the plug had water in it (or was staged). We don't know if the power on that circuit was off, running the reverse cycle air conditioning and or more stuff equal to or slightly more than 30 amps. We also don't know the quality of his installation of the Smart Plug. I could see a terminal not being tight enough, causing arching and the melt down. I also find it troubling that for all the detail and BS in the video, there was no close video examination of the cord terminals and no examination of the Smart Plug receptacle on the inside of the boat.

Probably none of this matters as the video is probably leverage to get replacement components from the manufacturer.

I know, I'm being cynical.

Ted
Click to expand...

I had a couple of issues with the Gen 1 Smart Plug and the manufacturer couldn't do enough to make sure I had the replacement parts I needed to update to Gen 2. They were super good that way, so doubtful they'd give this guy any push-back if they thought there was any chance to make it right,,
 
Smart Plug melt Down

I can tell you that the plug was a Smart Plug BUT I can also tell you that the cord was not a Smart Plug.

Smart Plug cord is orange and in the video those cords are yellow.

What someone had done was to cut off a Marinco plug and fitted a SmartPlug on the end.

Who knows the capability of the person who did that.

All bets are off for a reman cord set.

I don't see any way to respond directly to the video, no way to enter a rebuttal for a problem that wasn't because of it being a Smart Plug setup.

Hope the people who did the post read my post.
 
SmartPlugs are far superior in terms of contact area and my 2 have given years of trouble-free service.
Don't be discouraged by tales of issues caused by poor installation.
 
Nepidae said:
I can tell you that the plug was a Smart Plug BUT I can also tell you that the cord was not a Smart Plug.

Smart Plug cord is orange and in the video those cords are yellow.

What someone had done was to cut off a Marinco plug and fitted a SmartPlug on the end.

Who knows the capability of the person who did that.

All bets are off for a reman cord set.

I don't see any way to respond directly to the video, no way to enter a rebuttal for a problem that wasn't because of it being a Smart Plug setup.

Hope the people who did the post read my post.
Click to expand...
But smart plug vends the plug and outlet in this manner. In fact it was only way one could install the first generation. The cordset came later.

I did mine this way. Oh...10 years ago, perhaps. No issues.

I'm pretty keen on following technical procedures, as it is my job to write them, among other things. I thought the Smart plug instructions were straight forward and well-cautioned.

They made no mention of using white plastic tape on the plugs or on the outlets. He must've suspected a leak, or had one in the past.
 
Last edited:
GoneFarrell said:
What I've seen too many times is that the plugs are at an angle in the sockets due to weight of wire or getting tugged as the boat moves in moorage.

The misalignment means poor contact, heat, then the smoke gets let out of the wire and connectors.
Click to expand...

That is one of the advantages of a Smart Plug. It plugs straight in and has 2 side clips that lock in and when you put the metal cover plate down it also hooks onto the plug so they are very solid and don’t wiggle around. Compared to a L5-30 they are much more solid and way easier to get plugged in. No messing around trying to get the plug lined up and then trying to start the locking ring in the threads. My plugs are down low on the side so it was always a PITA to plug in the L5-30. However the Smart Plug is simple and easy to plug in. And it is solid.
 
Nikko said:
I had a couple of issues with the Gen 1 Smart Plug and the manufacturer couldn't do enough to make sure I had the replacement parts I needed to update to Gen 2. They were super good that way, so doubtful they'd give this guy any push-back if they thought there was any chance to make it right,,
Click to expand...


I hate to talk badly of people but I am certain that the quality of work was the issue.


These folks have been living aboard in Chicago since 2014, the you tubes only go back a few months and some of them made me wonder about some other wiring i saw he did. They have been blogging since 2014.

waterwethinking.blogspot.com/2014/


You should see how he attached to multiple pedestals and multiple 30 amp cords (not the boat power more) and splitters to heat the boat...




oh and pics of my 30 to 50amp upgrade, I'm a bit anal about electricity...
https://www.facebook.com/media/set/?set=a.10216804598211841&type=3
 
Last edited:
You must log in or register to reply here.

Similar threads

Nick F
Has anyone melted down their old bronze?
Replies
29
Views
3K
Nick F
Nick F
SteveK
I have a resetting breaker, trips and resets in a few minutes
Replies
15
Views
1K
catalinajack
catalinajack
D
Freeze Plug
Replies
2
Views
320
dosched
D
Captain_Michael
Trent- Severn Waterway
2
Replies
31
Views
3K
Still Boating
Still Boating
grahamdouglass
Raymarine smart controller
Replies
5
Views
764
tpbrady
tpbrady

Latest posts

Back
Top Bottom