The black wire on my plug is burnt up...

[groundhogy]

So after the winter, I pulled up and moved.

I was using the 50A socket with the 50-30 adapter.

One of my connections was burnt up and the plastic was melted.
The flat prong was black.

The part that plugs into the pedestal was ok. That part was also shielded from weather.

The 50-30 adapter part is about 12" long.
The 50 side was ok as mentioned above. The problem was on the 30 side, which was in the weather.

The black wire terminal was the one that was burnt up.

Anybody have insight on causes here?

[ol_Bombero-JC]

myredracer wrote:

cavie wrote:
Ease up guys. Let's get back to electric for newbies 101. Save the electric engineering 2.0 for another forum. :):)

Agreed! Been retired too long and this stuff gives me a headache now. 😞

"BUMP" for an old thread!
(which is linked to a newer one).

To solve the loose 30Amp plug at campground pedestals - use the 50AMP
(there usually is one) - with a 30 to 50 adapter...:W

Never found a loose 50amp, but "sloppy" 30s are common!...:(

Do your fellow campers a favor - politely inform the campground of the
"situation" at the pedestal on site #.....

AND -

you will be posting the "problem" on site #.... at campground
(name) on all the forums you visit.
May or may not expedite repairs - but can't hurt - it's also a "heads up" for the next visitor!...:C

~

[time2roll]

myredracer wrote:
But the 80% rule doesn't apply to plug-in loads. That would be like saying you can't plug a 1500 watt portable heater into a 15 amp receptacle because it draws more than 80% of 15 amps (12.5 amps). DW has a blow dryer that is rated 1875 watts (15.6 amps) and same thing there.

1500 / 125 = 12 amps
15 amp outlet x 80% = 12 amps
Coincidence? Heater possibly runs continuous.

1875 / 125 = 15 amps
Hair drier is not considered a continuous load.

Of course most voltage will be 115 to 120 at the connector so these items will draw a bit less.

[myredracer]

.

[myredracer]

.

[myredracer]

cavie wrote:
Ease up guys. Let's get back to electric for newbies 101. Save the electric engineering 2.0 for another forum. :):)

Agreed! Been retired too long and this stuff gives me a headache now. 😞

[cavie]

Ease up guys. Let's get back to electric for newbies 101. Save the electric engineering 2.0 for another forum. :):)

[cavie]

myredracer wrote:

CA Traveler wrote:
Keeping it simple just follow the NEC rule of 80% continuous load. I doubt any RV pedestal or RV panel is rated for 100% continuous load.

In this non simple article there is a lot more information. CLICK

I understand what you are trying to say. But the 80% rule doesn't apply to plug-in loads. That would be like saying you can't plug a 1500 watt portable heater into a 15 amp receptacle because it draws more than 80% of 15 amps (12.5 amps). DW has a blow dryer that is rated 1875 watts (15.6 amps) and same thing there. (Interestingly, like portable heaters also, only has a 16 gauge cord.) There's other examples where plug-in loads exceeds 80% of a breaker on a circuit being plugged into. You can also have multiple receptacles on a circuit and easily exceed the 80% rule.

If you can't or shouldn't exceed 24 amps on a 30 amp pedestal, why does the NEC require a 30 amp load allowance per pedestal? Why doesn't a pedestal say you shouldn't exceed 24 amps or an RV have a sticker on the power inlet saying the same? There is simply nothing in art. 551 that requires an RV to be considered as a continuous load.

RV pedestals have to meet UL standard 231 and molded case breakers, UL 489. I think you'll find that you have to look at a UL standard for a piece of equipment as whole, not individual components in it. I haven't looked for a copy of UL 231 and don't know what the details are in it.

A bit of a head scratcher question and no immediate answers pop up on google. IMHO, it boils down to RV and RV park rules in art. 551 and the fact that RVs are plug-in loads, not hardwired like in a building.

[myredracer]

CA Traveler wrote:
Keeping it simple just follow the NEC rule of 80% continuous load. I doubt any RV pedestal or RV panel is rated for 100% continuous load.

In this non simple article there is a lot more information. CLICK

I understand what you are trying to say. But the 80% rule doesn't apply to plug-in loads. That would be like saying you can't plug a 1500 watt portable heater into a 15 amp receptacle because it draws more than 80% of 15 amps (12.5 amps). DW has a blow dryer that is rated 1875 watts (15.6 amps) and same thing there. (Interestingly, like portable heaters also, only has a 16 gauge cord.) There's other examples where plug-in loads exceeds 80% of a breaker on a circuit being plugged into. You can also have multiple receptacles on a circuit and easily exceed the 80% rule.

If you can't or shouldn't exceed 24 amps on a 30 amp pedestal, why does the NEC require a 30 amp load allowance per pedestal? Why doesn't a pedestal say you shouldn't exceed 24 amps or an RV have a sticker on the power inlet saying the same? There is simply nothing in art. 551 that requires an RV to be considered as a continuous load.

RV pedestals have to meet UL standard 231 and molded case breakers, UL 489. I think you'll find that you have to look at a UL standard for a piece of equipment as an assembly, not individual components in it. I haven't looked for a copy of UL 231 and don't know what the details are in it.

Circuit breakers are designed to operate at 100% but code typically doesn't allow connected loads to exceed 80% of their rating for loads considered continuous. Here's one article that says "CBs and other OCPDs can be sized at 100% of their rating for any NONCONTINUOUS load applications." Clifford Power (Note that "100% rated" breakers are not the same as standard breakers.)

A bit of a head scratcher question and no immediate answers pop up on google. IMHO, it boils down to RV and RV park rules in art. 551 and the fact that RVs are plug-in loads, not hardwired like in a building.

[myredracer]

CA Traveler wrote:
Keeping it simple just follow the NEC rule of 80% continuous load. I doubt any RV pedestal or RV panel is rated for 100% continuous load.

In this non simple article there is a lot more information. CLICK

I understand what you are trying to say. But the 80% rule doesn't apply to plug-in loads. That would be like saying you can't plug a 1500 watt portable heater into a 15 amp receptacle because it draws more than 80% of 15 amps (12.5 amps). DW has a blow dryer that is rated 1875 watts (15.6 amps) and same thing there. (Interestingly, like portable heaters also, only has a 16 gauge cord.) There's other examples where plug-in loads exceeds 80% of a breaker on a circuit being plugged into. You can also have multiple receptacles on a circuit and easily exceed the 80% rule.

If you can't or shouldn't exceed 24 amps on a 30 amp pedestal, why does the NEC require a 30 amp load allowance per pedestal? Why doesn't a pedestal say you shouldn't exceed 24 amps or an RV have a sticker on the power inlet saying the same? There is simply nothing in art. 551 that requires an RV to be considered as a continuous load.

RV pedestals have to meet UL standard 231 and molded case breakers, UL 489. I think you'll find that you have to look at a UL standard for a piece of equipment as whole, not individual components in it. I haven't looked for a copy of UL 231 and don't know what the details are in it.

A bit of a head scratcher question and no immediate answers pop up on google. IMHO, it boils down to RV and RV park rules in art. 551 and the fact that RVs are plug-in loads, not hardwired like in a building.

[Lynnmor]

DFord wrote:
My experience over the many years I've been RVing has taught me drawing over 25 amps on a sustained basis (like when the a/c is trying to keep up during the heat of the day or space heaters on a cool night) will always ruin a cord plug. The connection points just aren't good enough to carry that load continuously. As proof, I submit the many 30 amp sockets you'll find in every park I've ever stayed at. They don't get burned up that way because they're carrying more than 30 amps because the breaker prevents that from happening.

I think you will find that most plugs are smoked by outlets that have been abused by those that yank the plug while there is a load on it. I always plug in and out a number of times in the hope of scraping off some of the burned surface.

An unseen poor wire to blade connection inside the plug might be the problem that the OP experienced. Just another thing to consider when using cheap RV electrical parts.

[CA_Traveler]

Keeping it simple just follow the NEC rule of 80% continuous load. I doubt any RV pedestal or RV panel is rated for 100% continuous load.

In this non simple article there is a lot more information. CLICK

[DFord]

My experience over the many years I've been RVing has taught me drawing over 25 amps on a sustained basis (like when the a/c is trying to keep up during the heat of the day or space heaters on a cool night) will always ruin a cord plug. The connection points just aren't good enough to carry that load continuously. As proof, I submit the many 30 amp sockets you'll find in every park I've ever stayed at. They don't get burned up that way because they're carrying more than 30 amps because the breaker prevents that from happening. With the normal residual draw of an RV (due to battery chargers and refrigerators), only one high power device (like a hair dryer, microwave, electric water heater, air conditioner or space heater on high) should be used. When using one of these devices, turn the others off and you'll get by just fine. Violate these recommendations and figure on resetting the breaker and melting your plugs while ruining the park's pedestal socket.

[myredracer]

CA Traveler wrote:

myredracer wrote:

CA Traveler wrote:
Plus the maximum recommended sustained load is 80%. ie 24A for 30A power.

Where does that come from? Except for the condition of the receptacle in a pedestal and your shore power plug, you should be able to draw 30 amps continuously.

It's an NEC recommendation.

With risk of over-complicating things and making it too long:

I've never heard that being called a code "recommendation". Either there has to be an 80% derating applied depending on load classification or not. Max. voltage drop is the only code recommendation I'm aware of. An 80% derating factor does apply to fixed hard-wired loads in buildings but RVs and RV parks are specifically covered by article 551 in the NEC and there is no mention of continuous or non-continuous loads and derating there.

Art. 551.73 requires an allowance of 3600 VA per individual 30 amp site (which is then subject to demand factoring for multiple sites on a feeder or service). There is no requirement to increase a branch circuit, feeder or main service by 25% (ie., derate to 80%) within art. 551. Consider also that RVs are plug-in loads and there is no way loads can be monitored or limited so RVs will keep on drawing current up to the point a pedestal breaker will trip. You don't hear about a 30 amp breaker (or 50 amp) in a pedestal, RV panel or RV park panel tripping very often and can usually be due to overloading.

RV-ers often max. out in the summer with AC units and other loads, esp. with 50 amp RVs using 50/30 adapters. And then there's autoformers being used in some cases which can result in a maxed out pedestal breaker. Voltage drop in RV parks/CGs is a common issue in the summer due to inadequacies of the NEC but that's whole other discussion.

Breaker operation/performance is def. affected by heat. (Breaker temp. cannot exceed 90C in a 40C ambient.) The temp. it will reach includes the type of enclosure they're in. Pedestals have a single breaker operating and lot of internal volume compared to panels in a building which can have up to 42 branch breakers plus main in a cramped space. Breakers, RV pedestals, "regular" panels and panels in RVs all have their own applicable UL standards and the breaker manufacturers have relevant info. If I had the time, I'd dig deeper into all this. But it would waay over-complicate this thread anyway. 😞

Having said all that, if a pedestal appears to be in poor shape or obviously is, drawing up to 30 amps for extended periods could be asking for a meltdown. Drawing even 24 amps could potentially be too much. If an RV-er is knowledgeable to know about this stuff, it comes down to maybe checking the plug/pedestal connection temp. and a judgment call.

[myredracer]

.