User Tag List

Page 13 of 13 FirstFirst ... 3 11 12 13
Results 121 to 130 of 130

Thread: Circuit Breaker teardown and defective Siemens latching mechanism

  1. #121
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    39,679
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by tersh View Post
    kwired. In your expert opinion. How many times do you think you can bend up and bend down the same portion of the wire for say AWG 3 and AWG 2 or in between before they suffer microscopic breaks in the cooper metal?
    How many times are you or whoever you are talking about bending it? Copper is very malleable compared to steel, I don't even want to guess.

    Find yourself a scrap of say 14 AWG copper and a similar sized piece of steel wire. Bend the steel back and forth several times, then touch the part that you were bending - may be hot enough to burn you, keep bending it, won't take just too long until it breaks. Now do same with the copper - bet you can do it 5 to even 10 times longer than it took to break the steel and it still is intact. Do you or your installers ever flex it that much during installations? I sure don't so it is not an issue for me.
    I live for today, I'm just a day behind.

  2. #122
    Join Date
    Nov 2018
    Location
    new york
    Posts
    454
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=mbrooke;1977963]
    Quote Originally Posted by tersh View Post

    Yes. It is lesser, but, when compared to the IEC 35mm2 is rated 125amps with 70*C insulation when in conduit not in contact with thermal insulation.

    If we assume 90*C insulated wire, then 35mm2 is rated 164 amps in conduit not in contact with thermal insulation.


    Clipped direct ratings are yet higher for both.






    No idea why- In truth part of me thinks that your wire isn't actually 38mm2 but 42.41mm2 listed as 38mm2. Its a guess on my part- just seems odd to do it that way especially when you need specific dies when 35mm2 and 42.41mm2 is sitting on every shelf across globe.
    Let's tie up the loose ends (pun unintended) before I part with all critical information gained (before we disturb hbiss more). Well. I bought 1 meter of 38mm^2 (between AWG 2 and 1) because the electrician violated the bending rule of the feeder between main panel and subpanel (just short distance needing only 1 meter wires). I was taught that the bending radius should be outside diameter multiply by 8 and it shouldn't be bent more than once. He bent it 4 times. So I'll ask the contractor to give me more knowledgeable electrician. Consider me as engineer just verifying the electrical contractor quality of works.

    The following is the exact measurement of the conductor diameter of the Phelps Dodge 38mm^2 wire.





    It measures 8mm. In the Phelph Dodge table. The conductor diameter is listed as 7.8mm see https://phelpsdodge.com.ph/wp-conten...HHNTHWN-21.pdf


    I counted 20 individual cooper strands:




    Now let's talk about your AWG 1. In this web site:
    http://www.panduit.com/heiler/Select...B%207-7-11.pdf

    The AWG 1 conductor has range of 7.3 to 8.4mm. How come the range is big? What is your most popular wiring brand and what is the actual conductor size in diameter?

    How many strands inside each AWG 1?

    How do you think they compute the 38mm^2 or 42.41mm^2 in AWG 1? First. Let's take the diameter of 8mm. The Area is computed to be 53mm^2. See https://www.omnicalculator.com/math/circumference
    For your AWG 1 conductor size of 8mm. How did they come up with 42.41mm^2? Is it based on the strands? How many standard for AWG 1?

    I've been contemplating your statement "part of me thinks that your wire isn't actually 38mm2 but 42.41mm2 listed as 38mm2." Why do you think they would do that? Won't it be better to just use the American AWG 1 as 42.41mm^2 instead of using 38mm^2?

  3. #123
    Join Date
    Jan 2011
    Location
    United States
    Posts
    8,546
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by tersh View Post
    I didn't just think up the questions. All my questions were due to actual applications issues:




    The electrician is migrating the panel from plug in to din rail and he bends the wires up and down. So I wonder how many times it can happen before micro cracks in the cooper can occur. I was not asking about the radius which we know but trying to bend with minimum radius up or down (or in opposite directions). If he does it 10 times, the wire can fracture. It's 30mm^2 or exactly between AWG 3 and AWG 2. But I wonder if less than 5 times, how would the wires behave.
    Question- I'm sure I missed it- but why are you replacing that panel?
    I'm in over my head...

  4. #124
    Join Date
    Jan 2011
    Location
    United States
    Posts
    8,546
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by tersh View Post
    [I see. This explains why a 5mA GFCI can protect an entire house without leakages because all the devices were isolated. Should there be EGC or GEC. Then it can nuisance trip on dielectric insulation decay and current leakages to the EGC or GEC.
    Yup- they are for the most part isolated.

    Keep in mind the wires are still capacitively coupled to earth as well.

    I know EGC is important so in the event of ground fault, it should trip the regular breaker immediately without waiting for a person and a ground via GFCI, which is only used for backup in the US.
    Yup- correct.

    But if the appliances have GEC. It should trip the GFCI as well so GEC should be at least a minimum. Hence will assign local electrical engineers for possible GEC installation and breaking concrete in the parking area next time.

    In theory this would work.
    I'm in over my head...

  5. #125
    Join Date
    Nov 2018
    Location
    new york
    Posts
    454
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by mbrooke View Post
    Question- I'm sure I missed it- but why are you replacing that panel?
    The panel was locally made. The bus bar stubs are not exactly 90 degrees but bent. All our panels were locally made and like that. When i bought the Siemens load center..they were exactly angled at 90 degrees..so impressive. When i learnt the breakers were just 1-pole and only of two pole trips..then rather than buying new double pole plug in breakers. May as well replace them with din rail. Most of our new home panels are din rail based now. But the electrical contractor and electricians im acquainted only have experienced with bolt on and plug in panels. So i need to look for contractor familiar with din rail.

    Btw dont miss msg 22. Maybe your AWG 1 only has 12 strands? It equates to greater area perhaps totally 42.41mm^2 where our 38mm^2 were comprised of smaller 2mm^2 stand size? We can compute by summing the areas of individual stands.

  6. #126
    Join Date
    Jan 2011
    Location
    United States
    Posts
    8,546
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    Quote Originally Posted by tersh View Post
    The panel was locally made. The bus bar stubs are not exactly 90 degrees but bent. All our panels were locally made and like that. When i bought the Siemens load center..they were exactly angled at 90 degrees..so impressive. When i learnt the breakers were just 1-pole and only of two pole trips..then rather than buying new double pole plug in breakers. May as well replace them with din rail. Most of our new home panels are din rail based now. But the electrical contractor and electricians im acquainted only have experienced with bolt on and plug in panels. So i need to look for contractor familiar with din rail.

    Btw dont miss msg 22. Maybe your AWG 1 only has 12 strands? It equates to greater area perhaps totally 42.41mm^2 where our 38mm^2 were comprised of smaller 2mm^2 stand size? We can compute by summing the areas of individual stands.
    Makes sense.


    Here are the number of strands for one very common brand that we use:


    https://www.southwire.com/ProductCat...rodcatsheet276
    I'm in over my head...

  7. #127
    Join Date
    Dec 2007
    Location
    NE Nebraska
    Posts
    39,679
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by tersh View Post
    The panel was locally made. The bus bar stubs are not exactly 90 degrees but bent. All our panels were locally made and like that. When i bought the Siemens load center..they were exactly angled at 90 degrees..so impressive. When i learnt the breakers were just 1-pole and only of two pole trips..then rather than buying new double pole plug in breakers. May as well replace them with din rail. Most of our new home panels are din rail based now. But the electrical contractor and electricians im acquainted only have experienced with bolt on and plug in panels. So i need to look for contractor familiar with din rail.

    Btw dont miss msg 22. Maybe your AWG 1 only has 12 strands? It equates to greater area perhaps totally 42.41mm^2 where our 38mm^2 were comprised of smaller 2mm^2 stand size? We can compute by summing the areas of individual stands.
    Number of strands has to do with how well those strands can be arranged into a circular pattern. Standard numbers are 1, 7, 19, 37,61. If you only had 12 strands all the same size, you can't make a circle with them without excessive gaps in the circle.
    I live for today, I'm just a day behind.

  8. #128
    Join Date
    Nov 2018
    Location
    new york
    Posts
    454
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=mbrooke;1977759]
    Quote Originally Posted by tersh View Post

    Very good



    A handle tie alone is not common trip. Meaning if one side trips, it will not kick off the other. But close enough- technically code does not require common trip for a straight 240 volt circuit.






    I know what this is about- because I discovered it by mistake when playing with a few GE breakers I took apart.


    If you take an older 2 pole common trip GE breaker, and then remove the handle tie, then turn one of the poles to off, were you to short circuit/over load the other pole thats still on it would jam trying to trip.

    Reason I found being that when one pole is switched off, the bulky common trip mechanism starts to lean forward. When the other pole unlatches, its catch hits the leaning forward mechanism and snags on it. This is a design flaw in older GE breakers under 40amps- but I do not entirely blame GE as double pole breakers are not intended to have their handle ties removed and used as 2 single pole breakers. But despite being a code violation to modify stuff like that, I've seen it done on a few occasions in the US when an electrician ran out of singles on his truck. Fortunately the modern GE, Homeline and Square D breakers I also played with did not jam in this mode.


    So to answer the question I doubt those breakers are counterfeit, it is normal for GE breakers to jam like that when the handle tie is removed.


    Regarding breaker compatibility- stick with the same manufacturer as who made the panel. What will work in your local panels I have no idea. But if GE has been getting the job done I'd stick with GE.
    I realized you were describing the 3 pole GE breakers (with arc flash damage) I just "teardown". I lost both springs when they flew into my table full of things. I'll look for them tomorrow before I try what you did. But I need to know something. When they jammed. Can they get back to normal by putting back the common handle and switching them to off or on. Or are they permanently defective? How do you get them back to normal?

  9. #129
    Join Date
    Nov 2018
    Location
    new york
    Posts
    454
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=mbrooke;1977759]
    Quote Originally Posted by tersh View Post

    Very good



    A handle tie alone is not common trip. Meaning if one side trips, it will not kick off the other. But close enough- technically code does not require common trip for a straight 240 volt circuit.






    I know what this is about- because I discovered it by mistake when playing with a few GE breakers I took apart.


    If you take an older 2 pole common trip GE breaker, and then remove the handle tie, then turn one of the poles to off, were you to short circuit/over load the other pole thats still on it would jam trying to trip.

    Reason I found being that when one pole is switched off, the bulky common trip mechanism starts to lean forward. When the other pole unlatches, its catch hits the leaning forward mechanism and snags on it. This is a design flaw in older GE breakers under 40amps- but I do not entirely blame GE as double pole breakers are not intended to have their handle ties removed and used as 2 single pole breakers. But despite being a code violation to modify stuff like that, I've seen it done on a few occasions in the US when an electrician ran out of singles on his truck. Fortunately the modern GE, Homeline and Square D breakers I also played with did not jam in this mode.


    So to answer the question I doubt those breakers are counterfeit, it is normal for GE breakers to jam like that when the handle tie is removed.


    Regarding breaker compatibility- stick with the same manufacturer as who made the panel. What will work in your local panels I have no idea. But if GE has been getting the job done I'd stick with GE.
    mbrooke. I'm trying to duplicate your jamming experiences. This is important to me because we may tolerate no EGC, no GEC, even arc flashing threshold residential panels, but not counterfeit breakers. Lol.

    In the GE breaker, the area shown inside the blue is independent of the On and Off lever. I mean, even when I turned it on and off. The components inside the blue area didn't move.



    Here I took video turning the breaker off and the common trip not moving:




    The common trip didn't move forward. It seemed independent of the on and off switching. How did you get it to move? I want to repeat what you experienced. Did you see the common trip piece move when the unit cover was opened or closed? When one opens a GE breaker, there are 3 areas where it must be pressed by the cover or it will go unaligned. It's the most difficult breaker I have worked with (for many hours) scratching by fingers because I had to press many areas at once just to try turning it on, off or trip it or reset it. Without the cover, the common trip can indeed move because of the misalignment. But when it is already covered, it is fixed (the blue area above). Please share how to duplicate it. Also when it's jam. How do you unjam it? By simply turning it on and off again with full covers on?

    I need to know because there are reports of hundreds of thousands of counterfeit breakers in the world. If what the guy in the province experienced was a counterfeit breakers. I may need to replace all my GE in the office building, and it will cost a lot. So I need to delve into this issue. Thanks.

  10. #130
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    24,513
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    I wouldn't expect the common-trip link to move when manually flipping the breaker; that's what the handle tie is for. The tripping mechanism doesn't depend on handle movement to trip, either internally or through the common-trip link.

    In other words, the link tells the other pole(s) that a breaker has tripped, not that the handle has moved.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •