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Old 11-04-2020, 07:23 AM   #41
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Originally Posted by oscar View Post
Color aside, I have stripped back wires as much as 5-6" and found oxidation.....
The conductor is green under intact insulation? Without exposure to air/atmospheric moisture that's just not possible. Now, if the wire was submerged, that's different.
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Old 11-10-2020, 05:45 PM   #42
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The conductor is green under intact insulation? Without exposure to air/atmospheric moisture that's just not possible. Now, if the wire was submerged, that's different.
Steve D. - The picture attached is of the hot wire connection that I found in my generator connection box when I discovered the breaker hot to the touch after having popped. The two wires on the left are the two hot wires from the brushes. The wire on the right is the hot wire to the breaker. What you see is after I removed the vinyl tape from the bundled three wires. It is not clear from the pictures but there was corrosion in both wires from the generator brushes. There was a lot of tape around the connection. The exposed wire you see was after I removed the tape and the insulation crumbled away. So, I am not understanding how that corrosion got there with no (apparent) exposure to air and certainly no exposure to water. I guess somehow there was a path to air exposure.

Now isn't that a frightening method of making that connection? You can see that a number of strands are broken. They were quite brittle no doubt from heat generated from resistance in the circuit. I had hoped to cut back the brush wires to find good wire to make make a butt connection and then rewire everything to a bus bar but the wires were brittle at least another six inches where it disappeared into the genset head. I now have to replace the brushes. Anyway, I thought I would share this picture with you.
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Old 11-10-2020, 05:52 PM   #43
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That is a well supported connection, not...
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Old 11-10-2020, 09:06 PM   #44
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Originally Posted by catalinajack View Post
Steve D. - The picture attached is of the hot wire connection that I found in my generator connection box when I discovered the breaker hot to the touch after having popped. The two wires on the left are the two hot wires from the brushes. The wire on the right is the hot wire to the breaker. What you see is after I removed the vinyl tape from the bundled three wires. It is not clear from the pictures but there was corrosion in both wires from the generator brushes. There was a lot of tape around the connection. The exposed wire you see was after I removed the tape and the insulation crumbled away. So, I am not understanding how that corrosion got there with no (apparent) exposure to air and certainly no exposure to water. I guess somehow there was a path to air exposure.

Now isn't that a frightening method of making that connection? You can see that a number of strands are broken. They were quite brittle no doubt from heat generated from resistance in the circuit. I had hoped to cut back the brush wires to find good wire to make make a butt connection and then rewire everything to a bus bar but the wires were brittle at least another six inches where it disappeared into the genset head. I now have to replace the brushes. Anyway, I thought I would share this picture with you.
Electrical tape over a conductor is far different than proper, molded insulation, which is essentially air-tight.

I assume this has been worked in previously, if it was taped rather than insulated?
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Old 11-11-2020, 04:49 AM   #45
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Steve D. - The original connection had all three three leads fastened thru that ring terminal and all three on the same plane. My plan was to extend the two generator brush leads - the two on the left - to a bus bar including the generator feed line. The lead to the right is the hot wire back to the panel through a Square D circuit breaker. That breaker box was the one too hot to touch. Anyway, the three leads were all well-wrapped with tape into a single bundle including the ring terminal with the short bolt. I removed the tape, with difficulty. The exposed wire you see is the result of the insulation having just crumbled away in my hand probably due to excessive heat. If you look closely you can see a crack in the insulation where the insulation ends.

This is not how I would have made that connection but, intuitively, I do not understand why this method failed, why these wires became cooked. My guess is that the Square D circuit breaker failed in some way and that created too much resistance in the circuit. Steve, if you had felt how hot that box was you would understand why I consider myself lucky that a catastrophic fire did not occur.

I am not even certain that a circuit breaker in the feed to the breaker panel is required given that there is main breaker in the panel that takes the generator feed, especially since the other generator we have on board - still working - is not wired through an independent breaker, at least as far as I can see.

As for the corrosion, it's a mystery to me how it could have occurred given how well-wrapped that three-wire bundle was.
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Originally Posted by Steve DAntonio View Post
Electrical tape over a conductor is far different than proper, molded insulation, which is essentially air-tight.

I assume this has been worked in previously, if it was taped rather than insulated?
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Old 11-11-2020, 05:43 AM   #46
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The failure (overheated wire insulation) in #42 was probably caused by the lack of a proper spring washer in the stack of terminal ends.

In use the ends will get warmer and cooler as the loads change. This heating and cooling changes the thickness of the wire stack , eventually the stack will loosen and overheat .

A copper star washer will help keep the stack of terminals tight to each other ,a great rain day project to clean the terminal ends and stick in a star washer, as a box of 100 is inexpensive .
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Old 11-11-2020, 06:10 AM   #47
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The failure (overheated wire insulation) in #42 was probably caused by the lack of a proper spring washer in the stack of terminal ends.

In use the ends will get warmer and cooler as the loads change. This heating and cooling changes the thickness of the wire stack , eventually the stack will loosen and overheat .

A copper star washer will help keep the stack of terminals tight to each other ,a great rain day project to clean the terminal ends and stick in a star washer, as a box of 100 is inexpensive .
FF, I didn't know that. But, in this case, the connection was rock-solid tight or so it seemed when I took it apart. I am still at a loss. In any case, when I replace the brushes, the new wires will go to a bus bar. There is plenty of room in the covered connections box on the generator to mount a bus bar.
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