Electrical C Honnections

[Dutch_12078]

Since it's nearly impossible for a 30 amp RV to draw anything close to 50 amps without tripping its own main or sub breakers, any risk is limited pretty much to just the cord assembly anyway. I'm pretty sure if RV dogbones had any built in protection, the vendor would note that as a selling point. As it is, the ones I have are all UL approved at least. And thanks for a fun and I hope educational discussion!

[57becky]

The biggest misunderstanding of the purpose of fuses or breakers is people think the device is intended to protect the load.  The device is there to protect the source of power from damage from a fault downstream of the device.  If you have a failure inside your rig, the 50 or 30 amp main is there to protect the park pedestal and the rest of their system from your failed system, not the other way around.  In your 12 volt system, the fuses protect the panel from a short or other failure on the one 12 volt circuit that has a problem.  Just like if you crash into a utility pole along a road and the wires come in contact with each other or the ground, the fuses upstream open up to protect the rest of the utility's system from the fault and the customers upstream of the fuses remain in power.

[oldjohnt]

Dutch

Good morning Dutch, looks like we got this pretty well wrapped up yayyyyyyyyyyyyyy We had fun and learned and enjoyed it but sorry we may have bored the others lol I enjoyed and appreciated our chat THANK YOU AGAIN

Indeed if a 30 amp RV draws more then 30 amps DOWNSTREAM OF ITS MAIN BREAKER (it doesn't see what's up stream) it will trip. As discussed the risk and danger of having ONLY 30 amp rated wire protected by a 50 amp breaker IS IN THE POWER CORD which is laying in dirt or water or gravel and can get stepped on or run over or pinched NOT inside the protected RV. If anyone added an extension cord onto their 50 amp RV I doubt they would use 30 amp wire HMMMMMMM.

I'm sure the short piece of wire and the plug and receptacle are all UL approved but I doubt the system and theory of a 30 amp rated power cord protected by a 50 amp overcurrent protection device could ever (the system not just individual components) be UL or NEC approved. The UL wouldn't like to see the use of 30 amp wire protected by a huge 50 amp breaker !!! even thought the dogbone wire and plug and outlet are UL approved HAVE TO ASK THEM DONTTAKE MY WORD FOR IT LOL

Anyway we agree the chances of a problem are unlikely and its a low risk but can agree the 50 to 30 dogbone (unless it has fuse wire inside or a fusible link which it may)  adapter creates a situation where ONLY 30 amp rated wire which should have 30 amp protection has instead the 50 amp in the RV pedestal, and THATS JUST NOT SAFE OR KOSHER even if its 99.9% safe and only a 1% chance to those willing to take it I SURE HAVE lol and I'm ONLY pointing out the reasons how and why and where it violates the whole spirt of the NECs Overcurrent Protection theory.  If 30 amp rated wire is used in the circuit it needs protected with a 30 amp breaker NOT a 50 like 50 amp rated wire uses. There's a reason why x rated amp wire is protected by that size of breaker NOT a breaker nearly twice as big !!!!!!!!!!!!!!!!!!!!!!!!!!

 

Becky, Good post, thanks and fun chatting with you (YEP the breaker is NOT to protect the load but the wiring yayyyyyyyy)

Indeed the purpose of the overcurrent protection device (fuse or breaker) is to protect the wiring coming out of and located downstream of the breaker between the breaker and the load so it cant pass more current then the insulation is rated for before it overheats and degrades and may open or be exposed to a person or an object ALSO AS A CONSEQUENCE it wont allow the load to draw more then the wire is rated for and also perhaps as a consequence what the load is rated for?????, but a load may have its own thermal overload protection.

The theory and design is again, compute the load,,,,,,,,,,,,,,,, size the wire with sufficient ampacity (I sized it for 125% of max continuous load),,,,,,,,,,,,,,,,THEN FINALLY SIZE THE OVERCURRENT PROTECTION DEVICE TO PROTECT THE WIRING (NOT the load although it can do that also).

SUMMARY I hope this helped as a learning experience for all of us and sure the risk is small and its done all the time and anyone has a right to use what they pleased  and I'm NOT here to argue with that ONLY pointing out if 30 amp wire is in a circuit it should be protected with a 30 amp fuse/breaker/fuse link or fuse wire and certainly NOTTTTTTTTTTTTTTTTTT a nearly twice the size 50 amp... I don't see how anyone could make an argument why 30 amp wire should be protected by a 50 amp breaker when that much over current which can melt the insulation THATS JUST NOT A GOOD AND SAFE POLICY but people can use it I they like...........

 

REGARDLESS a 30 amp rated power cord in the feeder circuit FROM the pedestal TO the RV WITH A 50 AMP CIRCUIT BREAKER                      JUST CANT BE SAFE OR NEC OR UL APPROVED  IN ANY DERN WAYYYYYYYYYYYYYYYYY but hey, sure, its often done and will continue I'm sure. The UL or the NEC would be happy if a person simply placed a 30 amp fuse ahead of to protect 30 amp wire ya know !!!!!!!!!!!!!!!!!!!!!!  Ever consider why at the RV power pedestal there's a 30 NOT a 50 amp circuit breaker for plugging in your 30 amp RV and its 30 amp rated cord HMMMMMMMM heres a hint BECAUSE 30 AMP WIRE NEEDS 30 AMP PROTECTION NOTTTTTTTTTT 50 think about it....

 

PS I have a 50 30 dogbone in my RV and I'm NOT arguing against its use only here to help and educate

God Bless all here and happy travels

John T Retired Electrical Power Distribution Design Engineer and rusty so nooooooooooo warranty my recall of the NEC  may be all wrong grrrrrrrrrrrrrrrrr

Headed to Church I will catch yall later

[Yarome]

1 hour ago, oldjohnt said:

I SURE HAVE 

As have I.

PS I have a 50 30 dogbone in my RV and I'm NOT arguing against its use

Ditto.

Headed to Church I will catch yall later

Always good to clear the chalkboard once a week... so you have somewhere to write THIS week! 

 

[oldjohnt]

Yarome, I am back and didn't get struck by lightning on the way out of church so I'm good to go for a while at least LOL Took the first wife to breakfast after church then went to Menards for home supplies NOW ITS NAP TIME

John T

[Randyretired]

The NEC and possibly UL appear blind to anything plugged into a plug.  For instance it is acceptable to connect 15 amp receptacles  to a 20 amp circuit.   The NEC requires the appropriate wire for 20 amps to the plugs but then allows 15 amp receptacles.   I have seen UL approved appliances with wire rated to handle the expected appliance load but smaller than most circuit breakers.  In fact I just looked at a UL approved extension cord that is rated for less than 15 amps.

[Randyretired]

I just looked at my 50 - 30 adapter.   It is UL approved and is wired with #10 wire.

[Dutch_12078]

Randy, and just finish it out, I'm positive that if your 50-30 adapter or 30 amp cord short out, the 50 amp breaker will pop. Assuming the breaker is working as designed of course...

[oldjohnt]

Randy, Thanks for chiming in and helping out, I enjoyed it.

(I apologize if this great discussion and learning experience is boring others PLEASE DONT READ IF SO LOL)

 You're sure right Randy, I, a life long sparky, have seen all sorts of small appliance cords using less the 14 gauge wire plugged into 15 amp receptacles and I'm sure the NEC has an exception allowing such and for proper use of light gauge extension cords . However I'm NOT aware of any NEC exception that permits the use of 30 amp rated wire ESPECIALLY A RUBBER COVERED LAYING IN WATER OR THE EARTH ON GRAVEL WHERE IT CAN EASILY GET RUN OVER OR STEPPED ON  with 50 amp overcurrent protection. NOTE the NEC "Tap Rules" and some  motor circuits do allow some limited exceptions but NOT this.  If a 30 amp RV power cord is used it requires a 30 amp NOT a 50 amp overcurrent protection device PERIOD. The RV pedestal which has a 30 amp outlet, guess what, uses a 30 NOT a 50 amp circuit breaker WELL DUH. The overcurrent protection device is to protect the feeders by limiting the current the wires and insulation can handle WITHOUT DAMAGING THE INSULATION. That's why a 20 amp breaker protects 20 amp wire and 30 amp breaker 30 amp wire and you DO NOT use a breaker higher then the wire is rated for ITS SIMPLY NOT PROPER OR CORRECT OR NEC OR UL APPROVED OR SAFE (except for some motor circuits and the tap rule exceptions) . Sure a 6 inch pierce of wire and an outlet and a plug can all be NEC or UL approved discrete devices, but I defy anyone to show where the NEC or UL says sure no problem use a 50 amp breaker with ONLY 30 amp rated wire in a circuit !!!!!!!!!!!!!!!!!!  ITS NOT THERE !!!!!!!!!!!!!!!!

NOTE sure the "Magnetic" portion of a thermal magnetic circuit breaker will trip on a dead short even if its a 50 amp breaker and 30 amp wire THATS NOT THE ISSUE OR SAFETY OR NEC. The reason why 30 amp wire needs 30 amp protection is so too much current which can ruin or damage the insulation cant be passed AND NEARLY TWICE AS MUCH 50 AMPS CAN CREATE ENOUGH HEAT TO DO JUST THAT. A dead short extreme high current trip is NOTTTTTTTTTTT only how a breaker is sized, its sized to protect the wire and insulation and sure a dead short can trip even a much higher breaker BUT THAT DONT MEAN YOU GO AROUND NOR DOES THE NEC PERMIT THE USE OF NEAR TWICE THE SIZE BREAKERS now does it ???

Listen guys you're taking this wrong, I'm NOT here to argue, only help and educate yall and illustrate why and how its unsafe and NOT NEC approved  to use 30 amp rated wire protected by a nearly twice as big 50 amp breaker IM SURE EVERYONE EVEN A NON ENGINEER OR NON TECHNICIAN CAN UNDERSTAND THAT. I bet in their home when they fed a 10 gauge wire 30 amp branch circuit like to a dryer or something THEY DIDNT USE A 50 AMP BREAKER hmmmmmmmmmmmmmmmm  imagine that lol

DISCLAIMER: Okay I tried my best to help and educate and don't feel bad if you don't get it because its impossible to teach in a few paragraphs what can take volumes of material and years of study practice and experience to understand and comprehend. I didn't get all this until I studied it and practiced it many years (with NEC by my side)  and attended numerous NEC seminars. Overcurrent Protection and the NEC treatment of it is NOT easy for non sparkies to understand, but surely anyone realizes there's a reason for the circuit breaker being sized to protect the wires rating and NOTTTTTTTTTTT sized nearly twice that !!!!!!!!!!!!!!    

SOOOOOOOOOOOOOOOO use whatever you like take, whatever risks you want, that's your choice NOT MINE OR ANYONE ELSES and all it takes to be safe is a simple 30 amp fuse (or even 30 amp fuse wire link which may already be there) to properly protect 30 amp wire.

PLEASE everyone use what yall like and take what risks you wish, its your RV or your or your kids or grandkids that are at risk NOT me. HOWEVER you have to admit I gave it my best shot and tried to help and educate but don't hold it against me if couldn't teach and convey in a paragraph  what can take years of education and practice and study and experience to fully comprehend. Overcurrent Protection isn't easy to understand, but hopefully yall have learned something and surely by now realize there's a reason why circuit breakers are designed for use with the same rated wire size NOT wire that can ONLY pass half what a breaker will permit without ruining the insulation PERIOD............

God bless all here, keep safe, use anything you like and feel comfortable with, I SURE TRIED MY BEST TO HELP so please give me credit for that lol but I cant teach a complicated subject and the entire NEC on an RV forum. Check out Mike Holts forum for that, he's a MUCH MUCH better teacher then I am for sure.

A special thank you and shout out to all who contributed, especially Dutch and Randy and Becky for their help and insight, best wishes and God Bless and keep you safe.

Post back any questions and I will continue to try my best to help, to educate, and most important maybe save a life. If that makes me a bad person, YOU CAN JUST CALL ME BAD !!!!!!!

John T   BSEE, JD Tooooo Longggggggg retired Electrical power Distribution design Engineer and rusty on the latest NEC so no warranty, this overcurrent protection theory may be all outdated but I doubt it lol but I'm never too old to learn so if the NEC or UL now permits the use of 30 amp wire protected by a 50 amp breaker PLEASE PLEASE EDUCATE US ALL I'm all ears.

USE ANYTHING YOU WISH, TAKE ANY RISK YOU LIKE, IS ALL FINE WITH ME...................   

[Randyretired]

Hi John,  My post was just to say the NEC and UL appear blind to what is plugged in to a receptacle.   I spent a little time as an electrical engineer a long time ago and I agree there is a slight danger of the RV cord or any cord shorting out.  It is as if it is beyond their concern.  I have read about a few home fires caused by cords shorting and the NEC sort of addressed this with arch fault requirements but that is another subject.  I occasionally use a 50- 30 adapter and just keep the risk in mind.

[oldjohnt]

Hi Randy, THANKS FOR YOUR THOUGHTS,  I hear you and for much part agree yayyyyyyyyyyyyyy lol One reason for the addition of Arc Fault Circuit Interrupters AFCI (which I agree with) is cheap flimsy wimpy extension cords ran under rugs and other flammables can so easy get pinched or dog or cat or toddler chewed and can have a minor "arcing" short that's NOT enough to trip a  20 amp breaker but can still start a fire. I also agree there's a slight danger in an RV cord shorting out butttttttttt hey remember its the ONLY part of the 50 amp protected circuit (with only 30 amp rated wire) that's laying in water or gravel easily ran over or stepped on by your barefoot grandkids  !!!!!!!!!!!!!!! Hey that's NOT like a kitchen blender on the countertop lol

Indeed you're sure right, the NEC as I recall it is more concerned with the branch circuit feeder wiring to outlets then that which is plugged in  (talkin short runs to small appliances, NOT a big RV main distribution panel) BUT YOU HAVE TO ADMIT those dogbones, unless 30 amp fuse link or fuse wire protected, CREATE A SITUATION WHERE THAT BIG LONG IN WATER OR GRAVEL and part of the 30 amp RV's electrical service can given a minor particular short draw up to 50 amps and that's enough   to melt the insulation and expose 120 VAC to water or the kids or the RV etc WHICH A 30 AMP BREAKER OR FUSE OR FUSIBLE WIRE LINK COULD PREVENT as the insulation wouldn't be compromised  YOU GOTTA GIVE ME THAT FELLOW ENGINEER RANDY LOL

Ya gotta realize, this (50 amp pedestal outlet to dogbone to RV with 50 amp breaker but ONLY 30 amp rated wire ) is the main supply feeder circuit FROM the pedestal TO the RV main distribution panel and that's NOT quite the same as plugging in a countertop blender !!!!!!!!!!!! When you feed a panelboard (including an RV panel) you for sure protect the feeders with the correct breaker NOT one nearly 50% bigger !!!!!!!!!!!!! 

I  really really enjoy chatting with you and the other sparkies and engineers and engineering technicians and appreciate your input on this way too long thread lol  That's why I love it here and help when I can, such a fine group of knowledgeable GENTLEMEN  all willing to help

I think we pretty much agree, but where not we can agree to disagree as professionals and gentlemen, all just trying our best to help

PS for those unaware, fusible wire link can often look just like a regular piece of wire but it serves as a fuse and overcurrent protection device as well !!!!!!!!!!!!!!! 

PS who started this mess anyway LOL Yarome warned me but nooooooooooooo I had to jump right in there, that's just how an old engineer, technical writer and an attorney is wired, we just cant help ourselves ............. 

NOTE I used my 50 30 dogbone ONCE in my life. The 30 amp cord was coiled nice n neat on concrete and there were no kids with us and it was on dry surface.

BOTTOM LINE if you're willing to accept the risk, use the dogbone and nothing else HOWEVER, if you're super safety conscious  and NOT willing to take the risk, simply add a 30 amp fuse PIECE OF CAKE so cheap n easy and it could save a life or prevent a fire YOUR CHOICE NOT MINE..........I remain confident, however (sure I may be wrong) its an NEC violation but KNOW its unsafe (even if low chance) based on my experience, education and a nearly a life long engineering career involving proper Overcurrent Protection.

Thanks Randy fellow Engineer, God Bless you and all here

John T

[Ray,IN]

Well, the OP's thread topic is completely off the rails now.

 

How would a 30A RV power cord overheat from being connected to a 50A breaker when the 30A RV panel breaker limits amp-draw to 30A? The cord will never see over 30A continuous-duty.

[oldjohnt]

7 hours ago, Ray,IN said:

How would a 30A RV power cord overheat from being connected to a 50A breaker when the 30A RV panel breaker limits amp-draw to 30A? The cord will never see over 30A continuous-duty.

GREAT QUESTION NEIGHBOR RAY I answered it above but here goes again:

The 30 amp main breaker in the RV panel ONLY sees and registers the current downstream and AFTER the breaker.

It DOES NOT see or register ANY current upstream IE in the RV power cord all the way back to the breaker in the RV parks power pedestal

Due to a short or fault in the RV power cord where it lays in water or on sharp gravel or where its exposed and can easily get ran over or stepped on by barefoot kids THE RV MIAN BREAKER DOES NOTTTTTTTTTTTTTTTTT PROTECT THAT

There can easily be a fault in that exposed RV power cord BUT THE RV PANEL CIRCUIT BREAKER DOES CAN NOT PROTECT AGAINST THAT.

Soooooooooooooo Ray while its indeed true True AS YOU STATED the RV 30 amp breaker limits amp draw to 30 A.   That's ONLY downstream and after the main breaker and it DOES NOT limit the 30 amp power cord to 30 amps which has a circuit breaker nearly twice as big of 50 amps. ALSO however, and with all due respect, its NOT true what you said "The cord will never see over 30A" because the "cord" IS NOT protected by the downstream and after 30 amp main panel breaker which ONLY protects current out of the panel AFTER the main breaker NOTTTTTTTTTTTTTTTTT the "cord"

 50 amps in wire that's ONLY rated for 30 can degrade or melt the insulation so there's live hot wires exposed which can get to water or the RV frame or your barefoot kids.

FINNALY sure the risk is small and its been done no problems ever but it remains with 30 amp wire in the circuit FROM the pedestal TO the RV  there should be 30 amp protection NOT 50 which if using a 50 to 30 dogbone can be so easily cured by a 30 amp fuse or if the dogbone has a 30 amp fuse wire or fuse link already built in. Remember this is the circuit   FROM   the pedestal   TO   the RV main panel, which has 50 amp protection and therefore requires 50 amp rated wire throughout, NOTTTTT 30 amp, and in converse   FROM  the Utility   TO    the main RV panel with 30 amp rated wire present (dogbone to 30 amp RV) requires 30 amp protection ITS NOT THAT HARD TO UNDERSTAND !

Fir those willing to accept the risk do nothing, for those who aren't risk takers and fear electricity and are over safety conscious as I (Electrical Power Distribution Design Engineer), I have to be on record as saying I RECOMMEND YOU ADD THE FUSE if the dogbone doesn't already have fuse wire or a fuse link.

Your risk your choice.......

Ray, after my trip we will get together for breakfast

John T

[pethier]

Soooooooooooo, does anyone have an example of this actually happening?

[oldjohnt]

30 minutes ago, pethier said:

Soooooooooooo, does anyone have an example of this actually happening?

GREAT QUESTION I sure don't but it would be hard to trace it down had it happened somewhere if it were ever even publicly documented??? Just because one hasn't read it in some newspaper or electrical industry publication don't prove its NEVER happened.  I DO KNOW many requirements and especially changes in the NEC (I had to attend update seminars ) came about because there was a fire or someone got killed thus the changes were made so it didn't happen again. SURE the risk is small and its probably more risky then driving the RV in the first place grrrrrrrrrrrrrr so as I said if one is willing to accept the risk that's their free choice I'm not here to stop them.

PS one  may ask in response, can anyone show an example or prove its NEVER happened ????   In my long electrical power career I saw and read too many horror stories where an unsafe electrical  installation started a fire or got someone killed Grrrrrrrrrrrrrrrrrrrrrrr Sorry I'm just gun shy and over cautious when it comes to electrical safety, I respect the *&^%$% out of it lol

Fun chatting with you and others, take care be safe and God Bless

 

John T

[Dutch_12078]

What John doesn't mention is that the damaged cord dangers he mentioned can be just as dangerous even when the 30 amp cord is plugged into a 15 amp outlet.

[Kirk W]

1 hour ago, oldjohnt said:

The 30 amp main breaker in the RV panel ONLY sees and registers the current downstream and AFTER the breaker. Due to a short or fault in the RV power cord where it lays in water or on sharp gravel or where its exposed and can easily get ran over or stepped on by barefoot kids 

1

And lightning does strike and has struck people out of a clear sky!  There is nothing that we do which has no risk at all, and using one of those adapters to connect a 30A cord to a 50A outlet has extremely low risk as long as a visual inspection of the cord and adapter are both in good condition. 

[oldjohnt]

Just now, Dutch_12078 said:

What John doesn't mention is that the damaged cord dangers he mentioned can be just as dangerous even when the 30 amp cord is plugged into a 15 amp outlet.

RIGHT ON DUTCH thanks for pointing that out !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! You're a good man. HOWEVER while I of course agree its dangerous, with all due respect to you I don't think its quite "just as dangerous"  

I'm sure you're already aware, if plugged into a 15 amp outlet protected by a 15 amp circuit breaker, if there's a fault in the 30 amp RV power cord that cant draw over 15 amps because the breaker would trip, unlike if it were protected by a huge 50 amp breaker, WILL NOTTTTTTTTTTTTTTTTTTTTTT MELT AND DEGRARDE THE INSULATION where open non insulated 120 volt wiring could be exposed to water or the RV or your barefoot grandkids !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

15 or even 20 amps in a 30 amp RV power cord would NOT melt the insulation and expose live hot wires like if a 50 amp breaker was used. THATS THE ENTIRE REASONING WHY WIRE RATED AT X AMPS MUST BE PROTECT BY THE SAME X AMPS BREAKER but you already know that ................

THEREFORE ITS MY OPINION WITH ALL DUE RESPECT 30 amp rated wire protected at 15 amps IS NOT "just as dangerous"  AS 30 AMP WIRE PLUGGED INTO A BREAKER THAT CAN PASS 50 AMPS (can melt insulation) NOT 15 (which would NOT melt the insulation) 

 

THANKS AGAIN DUTCH I sure enjoy our chats and your expertise. This has been fun even if boring to the others I APOLOGIZE

 

John T

[Dutch_12078]

John, as a lawyer, I'm sure you're aware of how important exact wording is and misleading out of context quoting can be. I wrote " can be just as dangerous" quite on purpose. It only takes 0.1 - 0.2 or so amps to be lethal... 

[oldjohnt]

2 minutes ago, Kirk Wood said:

And lightning does strike and has struck people out of a clear sky!  There is nothing that we do which has no risk at all, and using one of those adapters to connect a 30A cord to a 50A outlet has extremely low risk as long as a visual inspection of the cord and adapter are both in good condition. 

I SURE AGREE, its indeed a small risk, thanks Kirk. YES a good visual inspection can do wonders for those of us (such as you) who know what to look for.

Its all about what risks a person is willing to accept, but remember, what risks can be avoided is one thing (Iike adding a 30 amp fuse in the above situation)  VERSUS those  risks over which we have NO control (struck by lightning)

I don't like either lol

Best wishes to you Kirk, Id sure love to visit you some time when were down Texas way. You have a 30 amp outlet I can plug to LOL LOL

John T

 

[oldjohnt]

44 minutes ago, Dutch_12078 said:

It only takes 0.1 - 0.2 or so amps to be lethal... 

RIGHT ON AGAIN, Thanks Dutch. Best I recall one of the design reasons why a GFCI trips at 5/6 milliamps is because subject to many variables, as little as 30 to 50 milliamps (0.030 to 0.050 amps) can cause fibrillation and/or not allow you to let go IE locked on. 

I THEREFORE DEFINITELY AGREE WITH YOU 100%  when you state 0.1 - 0.2 amps can be lethal. Hopefully, if the 30 amp rated RV power cord laying there in water or on sharp rocks possibly getting run over is properly protected (30 not 50 amps) so the insulation cant melt, live wires are less apt to be exposed  YAYYYYYYYYYYYYYYY

WE AGREE, is that cuz great minds think alike orrrrrrrrrrrrr even a blind squirrel finds a nut now n then YOU DONT HAVE TO ANSWER THAT DUTCH lol

As always, nice chatting with you, thanks again for your thoughts which I respect and appreciate

PS Dutch, I sincerely apologize if I mis interpreted your post MY BAD. I'm kind of in a hurry today and under pressure as I'm trying to finish two law jobs, getting the house ready for appraisal and inspection tomorrow (may have sold my farm) and a guy is coming to pick up may antique John Deere tractor I sold wooooooooooooo hoooooooooooooo 

John T

[Ray,IN]

Finally-I got it! Thanks for clearing away the fog for me JohnT. Now I'm wondering why the camping industry even makes a 50 to 30 adapter, let alone getting the design approved; however I do know this industry makes mistakes, one time I bought a new male 30A plug end, wired it up, but VOM testing showed the replacement plug color-coded wires were incorrect.

[oldjohnt]

You're welcome good neighbor, after we both return we gotta do breakfast. Looks like my farm may be sold so I will be HOMELESS and RV bound until next spring if and when we buy a new home .............

John T

[Kirk W]

9 hours ago, Ray,IN said:

Now I'm wondering why the camping industry even makes a 50 to 30 adapter, let alone getting the design approved; however I do know this industry makes mistakes,

The reason they are made is that they work very well and can be safely used. Even John admits to having used one. And they get U/L approval because they pass reasonable safety testing. 

[Jack Mayer]

43 minutes ago, Kirk Wood said:

The reason they are made is that they work very well and can be safely used. Even John admits to having used one. And they get U/L approval because they pass reasonable safety testing. 

Exactly. I can come up with all kinds of arcane failure scenarios for anything electrical. Most is covered by NEMA or NEC but unsafe condition scenarios can certainly be thought up.