Announcement

Collapse
No announcement yet.

What caused corrosion in these wires? water damage or joule heating, etc.?

Collapse
This topic is closed.
X
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    What caused corrosion in these wires? water damage or joule heating, etc.?

    These 2-pole breakers (single unit) was installed outdoor and exposed to water, wind, moisture, etc.
    Yesterday after 19 years the house no longer has electricity, so we called expert electrician and he replaced it with new ones (breakers and wires).
    I'd like to take this opportunity to review my college electrical lessons 25 years ago.

    Click image for larger version

Name:	b breaker 1.jpg
Views:	643
Size:	90.0 KB
ID:	2533090

    Click image for larger version

Name:	b breaker 2.jpg
Views:	572
Size:	89.2 KB
ID:	2533091


    The breaker is model G.E. TQD22150. How does the inside components work? any schematic of the internal mechanism (uhm.. Mbrookes, remember me? )

    Most important is I'd like to know what happened to the wires.


    Click image for larger version

Name:	corroded wire 1.jpg
Views:	568
Size:	86.5 KB
ID:	2533092

    Here you can see black thing enclosing some copper. In your expert experience. Is this cause by water damage or joule heating? Is the black thing soot from burning or caused by corrosion. Can too much current cause it? The wire size is 38mm^2. What produced the green thing? Please share the sequence of events where this can occur (resulting in the wires not able to conduct any electricity finally after 19 years). Thank you.


    Click image for larger version

Name:	corroded wire 2.jpg
Views:	571
Size:	73.6 KB
ID:	2533093

    #2
    The green is copper oxide. The black I'm not so sure but I suspect either burnt or degraded insulation, or a foreign substance that got in there and reacted with the copper.

    Can you rule out that these conductors didn't simply get so hot (due perhaps to poor torquing of connections, and/or breaker not properly tripping on overcurrent) that the insulation melted, exposing the copper to extra moisture and causing corrosion?

    Where I come from breakers like that usually last much longer than 20 years.

    Comment


      #3
      I'd say the combination of water and then heat.
      Master Electrician
      Electrical Contractor
      Richmond, VA

      Comment


        #4
        Originally posted by jaggedben View Post
        The green is copper oxide. The black I'm not so sure but I suspect either burnt or degraded insulation, or a foreign substance that got in there and reacted with the copper.

        Can you rule out that these conductors didn't simply get so hot (due perhaps to poor torquing of connections, and/or breaker not properly tripping on overcurrent) that the insulation melted, exposing the copper to extra moisture and causing corrosion?

        Where I come from breakers like that usually last much longer than 20 years.
        If copper was exposed to water or moisture, how does the corrosion look like?

        Imagine the wire has 20 strands. If half of the strands got corroded and no longer carry current, then the remaining strands would bear the whole load, overloading them, right?

        The breaker was broken because the screws can't be removed so the electrician just used hammer to break it.

        Comment


          #5
          I'd say water was the main culprit. When copper began to corrode the connection became loose causing overheating.
          Any copper left outdoors exposed to water will eventually oxidize and turn green.

          Fun fact; If you burn it in a campfire it will cause green flames.
          John,

          Comment


            #6
            I agree. From the description and the photos it appears to me as wet arc tracking. As noted, copper oxides when exposed to moisture and the "black stuff" is the breakdown of hydrocarbons found in the insulation of the wire and breaker.

            Sent from my SM-G973U using Tapatalk

            Comment


              #7
              Originally posted by S'mise View Post
              I'd say water was the main culprit. When copper began to corrode the connection became loose causing overheating.
              Any copper left outdoors exposed to water will eventually oxidize and turn green.

              Fun fact; If you burn it in a campfire it will cause green flames.
              Great theory. I think water from the rain reached the hole of the enclosure on top and drips into the breaker terminals at top. The bottom terminals don't have the green oxidation and wet arcing.

              Just wondering. Powerlines wires use copper too and without any insulation. Why don't they corrode?

              Comment


                #8
                I'm no expert tersh, but i do find heat attracts moisture , even the best sealed equipment created condensation due to it....~RJ~

                Comment


                  #9
                  From pictures you have posted in the past, first would be poor workmanship which would include installing equipment in areas they were not designed for.

                  Tom
                  TBLO

                  Comment


                    #10
                    Originally posted by ptonsparky View Post
                    From pictures you have posted in the past, first would be poor workmanship which would include installing equipment in areas they were not designed for.

                    No. When I bought the house which is part of 5 townhouse inside compound. The main panels outside street were already like this (each breaker services one house). Two already suffered lack of electricity. The others would fail in due time.


                    Click image for larger version

Name:	outside panels.jpg
Views:	533
Size:	85.7 KB
ID:	2533187

                    The greatest damages in the wires are in the top of the breakers where rain from the meters and top enclosure flow down the wires.

                    Comment


                      #11
                      Also keep in mind you have dissimilar metals at a joint. Those metals may be fine for the joint if kept dry and tight.

                      Outdoor connections on POCO lines are made up with items designed for the application, the breaker terminals were not ever intended to have water involved.
                      I live for today, I'm just a day behind.

                      Comment


                        #12
                        Originally posted by kwired View Post
                        Also keep in mind you have dissimilar metals at a joint. Those metals may be fine for the joint if kept dry and tight.

                        Outdoor connections on POCO lines are made up with items designed for the application, the breaker terminals were not ever intended to have water involved.
                        I looked at the removed breakers carefully, the wires have fused with the terminals from arcing (wet arc tracking? Why is it called "tracking"?) In the left terminal, the electrician could no longer turn the allen screw, he couldn't remove the wires that was why he just hammered the whole thing in order to replace it. What is this white stuff in the terminals? Is it corrosion? why white?

                        Click image for larger version

Name:	breaker terminal 1.jpg
Views:	512
Size:	73.5 KB
ID:	2533193


                        Click image for larger version

Name:	breaker terminal 3.jpg
Views:	505
Size:	77.4 KB
ID:	2533194

                        Click image for larger version

Name:	breaker terminal 4.jpg
Views:	508
Size:	84.2 KB
ID:	2533195

                        Comment


                          #13
                          Breaker terminal in your case is probably an alloy that is mostly aluminum. White stuff is very likely aluminum oxide. Outer layer of that lug may have been some other material (maybe tin plating) but is now gone or at least full of holes.
                          I live for today, I'm just a day behind.

                          Comment


                            #14
                            Originally posted by kwired View Post
                            Breaker terminal in your case is probably an alloy that is mostly aluminum. White stuff is very likely aluminum oxide. Outer layer of that lug may have been some other material (maybe tin plating) but is now gone or at least full of holes.
                            There is no outer layer. What you saw were just debris or corroded surface. Below are the lower terminals. There were less water exposure and damage that was why the wires were still intact.

                            Click image for larger version

Name:	lower lugs.jpg
Views:	522
Size:	90.2 KB
ID:	2533206

                            Are the above corroded main service entrance wires the worse you have seen in your life.. or have you seen worse?

                            Again I bough the house second hand with 4 neighbors. They don't want to replace the enclosure outside because it would cost a lot so I'd suggest to them to at least cover the following from rain. Any ideas how best to cover them? Maybe put plastic over the entire cage? What do you think?

                            Click image for larger version

Name:	outside panels.jpg
Views:	514
Size:	85.7 KB
ID:	2533207

                            Comment


                              #15
                              Long over due for a complete replacement. The rest of the breakers will follow and I doubt any of them work as is.

                              In places like India and Thailand they will put a water proof tarp over exposed equipment or build a wooden hut to keep rain away.

                              Comment

                              Working...
                              X