melting plug

[dustinl]

in the past 14 months i have had to replace the 30A plug that plugs into the rv parks box at least 3 times because 1 of the prongs overheats and melts my plug. need ideas on what might be the cause

[Learjet]

Me Again wrote:

rhagfo wrote:

dustinl wrote:
in the past 14 months i have had to replace the 30A plug that plugs into the rv parks box at least 3 times because 1 of the prongs overheats and melts my plug. need ideas on what might be the cause

OP has not been back in like 8 days, if same park, bad pedestal outlet. Different parks likely too much draw.

How do you draw too much without tripping the parks breaker?

From what I have read over the years...outlets are rated at 80% continuous duty or 24 amps continuous for a 30 amp outlet.

Maybe someone has the NEMA link.

I agree with this in the boat article linked above:

:The max continuous level at which you want to load any shore power circuit is 80%. Keep in mind this is when they are new and with clean tight connections. As the connections age corrosion can set in and this can create high resistance, especially with the highly susceptible 1938 twist-lock standard.

I generally don’t recommend loading a NEMA L5-30 30A circuit to more than 70% of its face value rating, especially in the marine environment. This means approx 21A on a 30A circuit. If you want to push it to 80%, and feel safe about that, the number is 24A. As a marine electrician I do not feel safe about that with the 1938 NEMA L5-30 plug standard."

[cavie]

the Twist loc is just fine if one is smart enough to twist it to the right and not too lazy to screw on the locking ring.

[ScottG]

So the smart plug hasn't been certified by UL or UL marine and they make no mention of the one I respect the most, CES. It has just "met their (UL) performance requirements". It still has no NEMA designation and is not included in the NEC - unless I missed it.

I guess time will tell.

[Me_Again]

enblethen wrote:
I went to Smartplug website. I saw nothing indicating Coast Guard, NEMA, UL or NEC approval.

http://www.emekmarin.com/e/product/smartplug-systems

https://smartplug.com/resources/faq/

[enblethen]

I went to Smartplug website. I saw nothing indicating Coast Guard, NEMA, UL or NEC approval.

[Me_Again]

pianotuna wrote:
Why is this "new" plug better than the current standard for RV's? Does it have greater surface area on the female contacts?

Some reading on Smart Plus:

https://marinehowto.com/shore-power-cords-smartplug-vs-1938/

While on our communities harbor committee(325 slip marina) we had Smartplug do a presentation when they were first getting started.

Marina fires really do happen. I was involved in this one.



I grabbed a couple other harbor committee members and we first put in this small cigar boom to capture small debris, when the fire fighters were done we put a large containment boom around the complete scene.

[philh]

What about smart plug cord and connectors? I know it won't fix the campground pedestal issue, but might help downstream?

Here's a link to a source.

Also, I've used a liquid connector "lubricant" in low voltage stuff, might it help with 120?

[pianotuna]

Why is this "new" plug better than the current standard for RV's? Does it have greater surface area on the female contacts?

[Me_Again]

enblethen wrote:
It will be a very long time for the "Smart Plug" be approved by NEMA.

1938 NEMA 30 amp twist lock.

[ScottG]

Me Again wrote:

ScottG wrote:
It's sad but the industry's NEMA TT30R/P design is really under engineered IMHO. Many decades ago when it was created, there were no electric water heaters (in RV's) or micros, TV's, large battery chargers, etc. Just some lights and the occasional space heater. Then add in poor quality, off shore parts and it only gets worse.
We use a lot more of the capacity if these "trailer" circuits now and while they work OK when everything is perfect, they don't like running a constant load at anywhere close to their 30A rating.
It's too bad we can't switch over to the marine undustrys 30A receptacle for pedestals. It seems to hold up better.

The 30A twist lock used in marinas is worst than the RV 30. It is a 80 or 90 year old hospital design and routinely causes marina fires.

This is the new plug for marinas, however it would take years to convert everybody.

https://www.westmarine.com/buy/smartplug--combo-inlet-connector-30a-125v-white--17415258?&mrkgcl=481...

Thanks, good to know. I guess I had my hopes up too much.
Wonder if the new one will ever catch on in the RV world...

[whiteeye42]

i think he is just a troll since he has not been back to even respond to any of the question that were posed to him about the problem

[enblethen]

It will be a very long time for the "Smart Plug" be approved by NEMA.

[Me_Again]

ScottG wrote:
It's sad but the industry's NEMA TT30R/P design is really under engineered IMHO. Many decades ago when it was created, there were no electric water heaters (in RV's) or micros, TV's, large battery chargers, etc. Just some lights and the occasional space heater. Then add in poor quality, off shore parts and it only gets worse.
We use a lot more of the capacity if these "trailer" circuits now and while they work OK when everything is perfect, they don't like running a constant load at anywhere close to their 30A rating.
It's too bad we can't switch over to the marine undustrys 30A receptacle for pedestals. It seems to hold up better.

The 30A twist lock used in marinas is worst than the RV 30. It is a 80 or 90 year old hospital design and routinely causes marina fires.

This is the new plug for marinas, however it would take years to convert everybody.

https://www.westmarine.com/buy/smartplug--combo-inlet-connector-30a-125v-white--17415258?&mrkgcl=481...

[Me_Again]

rhagfo wrote:

dustinl wrote:
in the past 14 months i have had to replace the 30A plug that plugs into the rv parks box at least 3 times because 1 of the prongs overheats and melts my plug. need ideas on what might be the cause

OP has not been back in like 8 days, if same park, bad pedestal outlet. Different parks likely too much draw.

How do you draw too much without tripping the parks breaker?