Electric problems_2003 Trillium_Outback

[steve dunham]

The wire terminal in your photo appears to be a standard AL/CU lug . The lug is made from an aluminum alloy which is then plated . When the connection from the wire to the lug is or becomes loose the termination heats under load and destroys the plating causing the lug to loose it temper . The more the lug heats the more it corrodes or burns and then the heating increases until you see what is in your picture. I have seen and replaced this type of connection failure many times in my years as an electrician .It is a common failure which usually appears in applications where the wire connection is not properly torqued , the termination is subject to high vibration or moisture, aluminum to aluminum connections or high current inductive loads . Your panel was not miss wired , you just had a component failure. The set screw in the burnt lug will be almost impossible to remove and even if you can remove it the lug is shot . The connection needs to be made from a clean shiny piece of copper to a clean shiny lug and the lug screw properly tightened .
In industrial applications ,it is common practice to take thermal photos and re torque all wire terminals on a yearly basis to prevent the problem you encountered.
In some cases the wiring lug is riveted to the buss bar and the rivet comes loose causing the exact same problem . Wadsworth / Bulldog panels were noted for this problem

[Bob Miller]

Quote: "Your panel was not miss wired , you just had a component failure"

Yes, the connection failed, probably due to it being overloaded by the way it is wired.

I don't know what connector he has on the other end of his shore cable, but even if it is a 30 amp plug and cable, the set-up will allow it to be overloaded before blowing a breaker. His drawing shows the power cable connected to the buss bar without any master breaker protection. He mentioned that he ran an electric heater for 18 months. That, plus a few other appliances, adds up to excessive current at the failed connection, leading to its demise.

I don't know what CSA sez, but in the lower 48 provinces a master breaker is always installed ahead of the individual load breakers, usually rated at the maximum size outlet the input cord and connection is designed to connect with, something he does not have.

Basically, if someone turned off the larger breaker thinking it was the MAIN, they would still have power on the branch circuits, as even Martha might say, "It's not a good thing"

[icerunner]

Originally Posted by Daniel A.

I'm going to say you had a major short either something has crossed over the connection made contact before the breaker.
Was there anything stored in there that could have fallen against the wires.

Car battery cables will burn the same way if shorted.
Have you checked the battery cables ?

I've seen battery cables go molten white from shorts.
Follow the hot lead from the battery back to the box looking for any damage to the cable insulation.

Thank you! I will check it out.
I checked battery is working so I thought it is time to turn into off-grid camping.

[steve dunham]

Originally Posted by Bob Miller

Quote: "Your panel was not miss wired , you just had a component failure"

Yes, the connection failed, probably due to it being overloaded by the way it is wired.

I don't know what connector he has on the other end of his shore cable, but even if it is a 30 amp plug and cable, the set-up will allow it to be overloaded before blowing a breaker. His drawing shows the power cable connected to the buss bar without any master breaker protection. He mentioned that he ran an electric heater for 18 months. That, plus a few other appliances, adds up to excessive current at the failed connection, leading to its demise.

I don't know what CSA sez, but in the lower 48 provinces a master breaker is always installed ahead of the individual load breakers, usually rated at the maximum size outlet the input cord and connection is designed to connect with, something he does not have.

Basically, if someone turned off the larger breaker thinking it was the MAIN, they would still have power on the branch circuits, as even Martha might say, "It's not a good thing"

Bob; The Panel shown in the photo is a MLO (Main Lug Only) panel.
Standard circuit breaker panel boards are made with a main breaker and without a main breaker (MLO).I have legally installed several 2000 amp services without a main breaker (See the "Six Disconnect Rule" in the NEC) The main breaker in a panel is sized based on the ampacity of the service or feeder conductors or buss ampacity. It would not matter if the trailer service cord was properly protected at its supply What you are seeing is the damage caused by a arcing /arc fault , which standard thermal magnetic circuit breakers can not sense or detect . If you look at the new NEC requirements for residential structures you will see the new more strict requirements for arc fault protection. In some cases circuits in residences require both ground fault and arc fault protection to the tune of about $100 per circuit. One never assumes anything is no longer energized just because you shut the breaker / switch off . That is what they make voltage testers for!!!

ALL THAT BEING SAID, INSTALLING A MAIN BREAKER WOULD BE GOOD IDEA

[Bob Miller]

Not to belabor the point, but the way his panel is set up, the buss load can exceed the "Ampacity" of the circuit, which is defined by the shore cable and connector size/configuration.

I work on a number of different RV's and I can't recall a single RV, less than 20 years old anyway, that didn't have a main breaker sized to match the shore cord & connector. In fact, even my 40+ year old Hunter had two breakers, the first was the main breaker, the second for the 120 VAC loads, the spaced for an additional breaker was unused, but available.

If this is a standard practice in certain makes, it voids the statement that you can't plug into to large a power supply. In this case the buss is breakered for 35 amps, well over the 20 or 30 amp capacity of the power cord, not a good thing.

If any one ever asks me about a master breaker being needed, the answer will always be YES, one selected to reflect the maximum current capacity of the shore cable & connector. One can't expect every RV user in America to be power savvy.