Check Your Shore Power Plug & Power Center Connections Regularly!

[oldjohnt]

Lynne, you're welcome and all this talk makes me want to run right out and inspect (for carbon) and tighten each and every one of my RV's electrical connections before we head out in a couple weeks. FWIW Usually what I call a loose connection STAYED LOOSE despite any accumulation of carbon and they didn't seem to somehow tighten themselves up. Its interesting to hear all your connections appeared to be "tight" and that the Green Ground wire hadn't completely burned through hmmmmmmmmmmmmmm that sheds more light on the situation, maybe NONE of any of our "guesses" are right lol That's NOT to say a loose connection (along with all other possible causes) still didn't contribute to your problem.

 

I NEED TO PRACTICE WHAT I PREACH so will go tighten and inspect all my wiring LOL

 

John T

[Kirk W]

 

the beige temperature-activated plug only was sold as a 2-outlet plug and would not fit there-

I recognize that device now. I have on like it that I use in our RV when winterized to keep a small amount of heat in the wet bay. While it don't look impressive, it seems to work fairly well but I do keep it to very small loads. With the way that you located yours, it should be quite safe even if it does fail ore melt down.

 

explains the circuit breakers flipping at certain points of this extended fry-out (when the faulty connection was overheating enough to pull more current than the circuit was rated for), right?

Looking back to your original problem, any time that you have a circuit breaker that continues to open for no apparent reason, you do need to investigate to see why. As Lou has explained, circuit breakers are affected by ambient heat because of the way that they are designed. The theory is that the small heat strip that is designed in will be the only significant heat source to impact the trip point, but if the ambient heat inside of the box containing the breaker is enough it will begin to lower the amount of current needed to make it trip. If I am seeing your pictures correctly, your RV has one of the WFCO load centers, which combine the 120V breakers, 12V fuses, and the converter all into one single box? If I am correct in this, it may be worth noting that I have experienced ambient heat problems impacting the trip point of circuit breakers in 3 RVs in recent years and all 3 were in WFCO load centers (the latest is my current travel trailer). If I am on track, this may be a factor in what happened to you. If loose connections are present generating enough heat to cause the sort of damage shown in your pictures that could easily also effect the trip point of a circuit breaker located close by. If a circuit breaker that has been carrying a load suddenly ceases to be able to do so, something has to have clanged and you need to investigate to see what caused the change.

 

We have a WFCO load center that will not carry the roof air conditioner if the plastic front door is in place but does just fine if I leave it open or remove it. I doubt that your problem was related to mine, but the ambient heat issue could easily be a common factor. It has been my experience that those load centers tend to be located in tight spaces and often have poor access, with makes the problem of analyzing what is happening much more difficult.

[oldjohnt]

To add just a bit to Kirks good information, some and perhaps your RV Panels Circuit Breakers??? are what are knows as THERMAL MAGNETIC BREAKERS. They contains dual purpose trip mechanisms (if I correctly recall???). They can trip out due to the THERMAL characteristics like he explained, PLUS Magnetically. Here's the difference if I recall correctly and the design hasn't changed.

 

1) The thermal portion causes a trip after a long extended period of heating if they are say drawing near their rated current. IE if you pull a constant say 19 amps for an extended time period, they can heat up enough so they eventually trip, even though yes, that's less then their 20 amp rating.

 

2) If you get a sudden even very short burst of high current like a short can cause, the magnetic function causes them to trip almost instantly EVEN IF THETIME IS VERY BRIEF.

 

NOWWWWWWWWWW that's based on recollection maybe 40 years old, so it may or may not be right.

 

I have to agree I've seen those panels often under a bed or a non vented location and for sure especially with the old technology noisy buzzing high heat Converter/Chargers IT CAN GET FAIRLY WARM WHERE THE BREAKERS ARE LOCATED.

 

Once more a combination of heat and arcing and loose connections and/or mis wiring and shorts may have allllllllllllllllll contributed to your problem.

 

Love sparky chat

 

John T

[lb311]

My original box was an all-metal Parallax power center. I thought about switching to a WFCO or PD for the replacement but the plastic used in their designs (door, etc) and, considering what I'd just been thru, I felt more comfortable sticking with another all-metal Parallax box (on the other hand, a melted plastic door would sure give one an obvious clue that something is very wrong inside their power box

 

They had discontinued my model, so I bought a 55-amp in the same dimensions, pulled out the "dumb" 1-stage converter and moved my Progressive Dynamics 3-stage converter upgrade & 12-v fuse panel over to the new Parallax box.

 

My circuit breakers had only flipped that one night, so I have a feeling it was probably heat-caused, but certainly could have been a temporary excessive current draw too. Either way, I'm glad I replaced them all when I replaced the power center-- cheap insurance.

 

Bill B-- thanks for the tips on the No-oxide and screw-tightening techniques. Will certainly give those a try!

 

Lynne

[oldjohnt]

Thanks Bill B,

 

I once had to perform a complex Short Circuit Current Capacity at a huge Naval Industrial Facility and the most current available even close to a 12,470 Y 7200 sub station was 8,000 Amps as I recall so 10K AIC breakers sufficed.

 

John T

[Kirk W]

My original box was an all-metal Parallax power center. I thought about switching to a WFCO or PD for the replacement but the plastic used in their designs (door, etc) and, considering what I'd just been thru, I felt more comfortable sticking with another all-metal Parallax box (on the other hand, a melted plastic door would sure give one an obvious clue that something is very wrong inside their power box

My opinion, you made the right decision as the Parallax is a much better one than WFCO I'd have to admit that it is based partly on visual factors but I find the main advantage of a WFCO product to be price. And I have also noticed that they are found most commonly in lower priced RVs.

 

They had discontinued my model, so I bought a 55-amp in the same dimensions, pulled out the "dumb" 1-stage converter and moved my Progressive Dynamics 3-stage converter upgrade & 12-v fuse panel over to the new Parallax box.

Now I am impressed. For an amateur you take on some serious work. Ever thought of taking a few courses in service work and trying a new career? There are some pretty successful RV techs on the road making a living while spending their time in the best of locations. Of course, no job can be the advantages of retirement, except perhaps on payday.

[lb311]

No, aspirations of an RV Tech Career-- I'm having too much fun volunteering at wildlife refuges (I know you can relate)! The PD converter move was honestly a lot easier than it looked-- it's just a single converter/charger unit that slides into the bottom of the power center, and the 12v panel just attaches to the metal box with 2 screws. Of course, the tedious part is reconnecting all the wires to the 12v panel, but they all went to the same spots they had been before, so no great rocket science required.

 

Lynne

[Ronbo]

I had a neutral co,e loose in a plug between the outside connector and my ems. It overloaded the ground lug on my twist plug and bunted the up. I had to replace the 50 amp plug and recepticle. I now check more often

[Kirk W]

No, aspirations of an RV Tech Career-- I'm having too much fun volunteering at wildlife refuges (I know you can relate)! The PD converter move was honestly a lot easier than it looked-- it's just a single converter/charger unit that slides into the bottom of the power center, and the 12v panel just attaches to the metal box with 2 screws.

Two things that you should realize. You are not the typical RV owner when it comes to us helping with small repairs, and being female makes you even more unusual. Most of us do at least at times tend to assume people are what we expect them to be, especially when we don't know much about them. Let me suggest that if you have not yet done so, take time to read Mark's article The 12V Side of Life as I do think you would get a lot from it, even though this was not a 12V problem. I have not yet found a really comparable article on the RV 120V system.

 

And I do get what you mean with the satisfaction of RV volunteer travels. Its one of those things that you kind of need to experience to really understand. Merry Christmas!