Anyone use a Smartplug?

[Britannia]

I installed a 250V/50A SP receptacle and plug after this happened to my Marinco last spring.

 

[diver dave]

Can't wait to see how we do with 500 Amp/400 Volt EV plugs and sockets.

 

[boathealer]

Folks, PLEASE inspect your shore power contacts regularly and use dielectric grease on them to prevent corrosion.

I'd be willing to bet MOST of the burned photos above would not have occurred were it not for corrosion present on the burned contact. Corrosion causes higher resistance. Higher resistance generates heat when high power loads are used. ......can be A LOT of heat.

I have used lots of the old standard Marinco type connectors on at least 10 different boats over 30 years and had no problems with any of them. I kept the contacts clean and checked them regularly.

A smartplug is certainly better, given the increased contact area yielding lower resistance. It can therefore tolerate SOME more corrosion before heating. But --- IT IS NOT THE SOLUTION to this problem!!! These, too can fail if not kept up. The solution is clean contacts - on any type of shore power cable.

 

[Britannia]

I agree with your recommendation to check and clean contacts. I would also suggest that the Smart Plug is much better weather sealed than the Marinco and so there is much less corrosion to contend with. Also, during the winter I will frequently run the boat somewhere close to the 50A capacity for extended periods of time. I think these high loads also exacerbate the problem.

Note that the failed plug/socket that I posted was less than a year old and showed very little signs of corrosion before failure.


Richard

 

[diver dave]

...

Note that the failed plug/socket that I posted was less than a year old and showed very little signs of corrosion before failure.


Richard

Ouch; what will be different next year?

 

[DDW]

A smartplug is certainly better, given the increased contact area yielding lower resistance. It can therefore tolerate SOME more corrosion before heating. But --- IT IS NOT THE SOLUTION to this problem!!! These, too can fail if not kept up. The solution is clean contacts - on any type of shore power cable.

I thought the Smartplug had the additional protection of shutting down if it got hot. It isn't just a better contact design. Cleaning the contact is a solution to corrosion, but thermal shutdown is the solution for burned contacts.

 

[Comodave]

They had to take the overheat shut down out since when it cooled down it would turn back on without notice. If you were working on the A/C while it was shut down, it could power back on and you wouldn’t know the circuit was energized. Too bad because the overheat shut off was a nice feature.

 

[Britannia]

Ouch; what will be different next year?

Well, I have replaced it with a Smart Plug so I'm hoping it will be just fine. We will see.

 

[boathealer]

Well, I have replaced it with a Smart Plug so I'm hoping it will be just fine. We will see.

If a clean, non-corroded terminal melted on the previous connector, then there may be some other weak-point in the system that manifested itself as heat at that particular point (highest resistance -- regardless of corrosion). In the past, for example, I have seen things like under-gauge wiring from the shore power inlet to a panel do this ---- at the connector.

Might be a good idea to load down the system and run an IR gun around all the pieces-parts to see if you can locate any hot spots.

Just a thought.....

 

[Britannia]

If a clean, non-corroded terminal melted on the previous connector, then there may be some other weak-point in the system that manifested itself as heat at that particular point (highest resistance -- regardless of corrosion). In the past, for example, I have seen things like under-gauge wiring from the shore power inlet to a panel do this ---- at the connector.

Might be a good idea to load down the system and run an IR gun around all the pieces-parts to see if you can locate any hot spots.

Just a thought.....

I agree. I have been checking the temperature on it regularly under load. So far so good. I do think that it could have been water ingress. We had a lot of rain last winter and I don't think it sealed very well. I will watch it very closely.

 

[psneeld]

30A twist lock plugs are just a bad design...they loosen and arc just too easily.


50A 125/250V plugs are not foolproof, but WAY better.


I see no advantage of a smartplug in the 50A arena...but definitely in the 30A.