Announcement

Collapse
No announcement yet.

Serious Electrical Short - Why didn't the circuit breaker trip?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    I had this same experience this spring. After heading south in March for warmer weather I had towed my Reflection 5th wheel in driving rain for several hours. When I reached our first RV park I connected to their 30 amp post. To warm up we started the fireplace and also an auxiliary electric heater. In a few minutes our GFCI outlet tripped. I turned of the electric appliances but could not get the GFCI to reset. I investigated our panel and did some voltage testing and was finding only about 60 volts in the AC circuits. Still not finding any problem I went outside to the 30 Amp post and found one leg tripped. I reset it and then was able to reset the GFCI. It was then that smoke started to fill the cabin. After shutting everything down and the smoke subsided I powered everything on again. The only circuit that I could find damaged was to the microwave in the slide??? We had not used the microwave during this episode. When I had time to investigate I found the two Molex connectors tied together laying on the chloroplast, one of them fried and the other one damaged. The heat melted a hole in an uninsulated plastic furnace duct to the rear vent in the coach(another problem I plan to modify). Thanks to the posts I am in the process of repairing the problem and feel very fortunate that a fire was not started.
    Dick and Jodi
    2020 Silverado Duramax
    2017 Reflection 27RL

    Comment


    • #17
      From several reports, an operating appliance (fireplace, microwave,etc) is not required to cause this failure mode. What appears to be happening is that a high resistance bridge is being created within the Molex connector due to water related corrosion. This is essentially a "resistive heating element" that draws enough power to melt the connector but not enough current to open the circuit breaker. Regardless of what type of replacement connector you choose, I think that dropping the coroplast to secure these connections as high and dry as possible, is worth the effort.

      Rob
      Cate & Rob
      (with Border Collies Molly & Angel + Kitties Hazel & Elsie)
      2015 Reflection 303RLS
      2022 F350 Diesel CC SB SRW Lariat
      Bayham, Ontario, Canada

      Comment


      • #18
        Originally posted by Cate&Rob View Post
        ... I think that dropping the coroplast to secure these connections as high and dry as possible, is worth the effort.

        Rob
        Rob, my 2021 Reflection has the molex connection secured in a holding device up high to the frame. In the picture below, you can see three Molex connectors secured to a plate that screws to the outside of the frame. (So I didn't have to drop the coroplast to get to these connectors). Clearly, mounting them up high is not enough, although it's better than leaving them down low on the coroplast! The foam sealing these molex connectors on the outside is brittle and fragile. When the slide goes in and out, that foam gets broken/falls off, allowing water to get into the connection. For newer trailers that have these connectors mounted to the frame, it's important to keep the foam seal on the outside in place, or use a better sealing material. Look at my pictures in post 15 of this thread to see how the foam has come off the pass-through area on the dinette side. That foam fell off one year after the manufacturing of my trailer.

        Click image for larger version

Name:	Short 1.jpg
Views:	255
Size:	146.7 KB
ID:	84649
        Home Base: Fairfax, Virginia
        2021 Grand Design Reflection 315RLTS Travel Trailer
        2002 Ford F350 7.3 Diesel 4X4 SRW

        Comment


        • #19
          Looks like loose conductors were arcing or stacked connectors caused overheating. Don't see any corrosion. Replace them all after trimming back the conductors at least two inches if you have the slack. Leave unbundled and test and check each for overheating at connectors hooked to shore power then battery if applicable. If OK insulate between connectors with a slice of header heat wrap, bundle carefully, retest for hot spots. If OK wrap bundle with waterproof elastic butyl pipe wrap or similar and retest. If OK reinstall and make damn sure to insulate or grommet any metal to conductor pass-through to prevent any possibility of chaffing.
          '20 Baby Grand 230RL
          '93 Ford F350, 4WD, Crew, long box, 7.5L, SRW
          Demco High Jacker 6076P-16k
          Demco custom rails 8552005-71

          Comment


          • #20
            Originally posted by Jimmer View Post

            Rob, my 2021 Reflection has the molex connection secured in a holding device up high to the frame. In the picture below, you can see three Molex connectors secured to a plate that screws to the outside of the frame. (So I didn't have to drop the coroplast to get to these connectors). Clearly, mounting them up high is not enough, although it's better than leaving them down low on the coroplast! The foam sealing these molex connectors on the outside is brittle and fragile. When the slide goes in and out, that foam gets broken/falls off, allowing water to get into the connection. For newer trailers that have these connectors mounted to the frame, it's important to keep the foam seal on the outside in place, or use a better sealing material. Look at my pictures in post 15 of this thread to see how the foam has come off the pass-through area on the dinette side. That foam fell off one year after the manufacturing of my trailer.

            Click image for larger version

Name:	Short 1.jpg
Views:	255
Size:	146.7 KB
ID:	84649
            That is a poor installation job in my eyes. I would not want those connectors any place that they could get moisture and this picture is a great example of a place where they certainly get moisture.

            If you can I would move your new connections inside above the coroplast and attach them to a cross member or something that is up off of the coroplast. Then seal around the wires that will go thru the plate. Spray foam is not a moisture sealant when used in the picture above.

            Brian
            Brian & Michelle
            2018 Reflection 29RS
            2022 Chevy 3500HD

            Comment


            • #21
              Jimmer -- I am dumbfounded that those non-weatherproof Molex connectors are attached to the interior sidewall of your trailer, sealed from the environment by the foam insulation (which can easily be pealed off). I'm sure you're thrilled (sorry, sarcasm) to have yet another project to avoid a repeat of the recent failure.

              You've got a week of work just catching up with all the threads you're going to write about all the recent upgrades!
              Forum moderators are not GD employees--we are volunteers and owners presumably just like yourself. Unless specifically mentioned otherwise, we have nothing to gain should you choose to purchase a product or engage a service we discuss on this forum.

              2017 Ford F-350 DRW, '19 315RLTSPlus

              Comment


              • #22
                The problem with trying to seal something against water intrusion in a wet location is that one small opening and you end up sealing the water in rather than keeping it out. I would still want to get these connections away from the frame rail and up high against the floor above. On the remote chance that they somehow get sprayed with water . . . this moisture can drain or evaporate. I think your first pictures show that these Molex connections, in their factory original location, retained water (maybe salt water?) and corroded to where a connection was made between line and either neutral or ground.

                My analogy is a tail light. Supposedly sealed around its perimeter with silicone. But . . . a small opening at the top allowed the space between the light and the wall to fill with water, held there by the intact silicone on the sides and bottom. Result . . . corroded light electrical connections and delamination in the wall. A corresponding opening in the bottom silicone would have probably prevented this. Drainage is important! You can probably guess why this “analogy” occurs to me .

                Rob
                Cate & Rob
                (with Border Collies Molly & Angel + Kitties Hazel & Elsie)
                2015 Reflection 303RLS
                2022 F350 Diesel CC SB SRW Lariat
                Bayham, Ontario, Canada

                Comment


                • #23
                  Failure wasn't corrosion related (based on pics) it was arcing (broken conductor) and/or stacking of connectors = o/h that's why fuse did not burn this was not a STG (short).

                  If you are worried about moisture dielectric grease is your friend- kind of a given for semi-/exposed stuff.

                  If you want to retain the OE connectors, advice has been posted. Highly recommend flame-proof insul between cons if stacking ( a BIG no-no).

                  I'd replace that whole mess w/ a clam deck seal for pass through and 3p 12awg w/p cable connector x3 (e.g.), splay and externally mount individually with p-clamps/ILF for better cooling and service or W/P M/F Bulkhead/panel mounts are another option if there's room and can't use a clam.

                  Make sure your connector is rated +30% over FAR.
                  Use adhesive filled heat shrink on all splices (with W/P adhesive filled heat shrink butt-connectors) and pig tails incl rear of connectors for support and W/Pi'nfg. Loom for chafe protection as nec.

                  Click image for larger version

Name:	2022-05-10.png
Views:	214
Size:	272.6 KB
ID:	84742
                  '20 Baby Grand 230RL
                  '93 Ford F350, 4WD, Crew, long box, 7.5L, SRW
                  Demco High Jacker 6076P-16k
                  Demco custom rails 8552005-71

                  Comment

                  Working...
                  X