Yeah, that's live!

[Richard Moore]

Direct short from the neutal lug to bus bar. I don't know how someone managed to do this, or what with (screwdriver?), but I'll bet it was quite exciting at the time.

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[randynavarro]

So does one call that out as problematic or just some crazy incident from the past?

[Ben H]

Direct short from the neutal lug to bus bar. I don't know how someone managed to do this, or what with (screwdriver?), but I'll bet it was quite exciting at the time.

I'll bet some underwear where purchased that day.[]

[hausdok]

Hee, hee,

Reminds me of when I lost the end of one side of my needle-nose pliars.

I was trying to pull some NM cable up into the panel a little more and didn't realize that I hadn't turned off the breaker. Anyway, I levered the head of the pliars on the housing and just about had it up into position when the jaws must have cut through the insulation because I was suddenly inundated with sparks and later thankful I'd been wearing glasses. It was only a 15-amp circuit but the last half inch of one side of the jaws on my needle-nosed pliars was completely gone and there was a nice deep arc groove in one side of the head.

No drawer change. My reflexes are akin to a galapogos tortoise's. It was all over before I even realized what had happened. Lesson learned - the insulation on that stuff is not nearly as tough as it looks.

ONE TEAM - ONE FIGHT!!!

Mike

[Richard Moore]

So does one call that out as problematic or just some crazy incident from the past?

There was a grab bag of other issues (panel and other stuff) so I was able to punt.

I reported it as "unlikely to be a current problem" but that they should have the electrician contracted to fix the other stuff confirm that.

[Chad Fabry]

unlikely to be a current problem

Always the punster.

[Marc]

The phenolic plastic or whatever hydrocarbon product that was used to construct the insulating components of the bus bar assembly is now carbonized and no longer has the insulating qualities that the manufacturer had intended.

Replace the busbar assembly if it is available, otherwise replace the entire panelboard.

The area where the arc occurred is not protected by the main breaker, assuming that this panel is a main panel. It is protected only by the utility fuse which protects the utility transformer, which might serve several residences at once. It's a big, super lag fuse. The consequence of the damaged area arcing over again at some point in the future could be enormous if not lethal.

Marc

[Robert Jones]

Nice sig Marc:)

[Jim Katen]

I agree with Marc. Time for a new panelboard.

- Jim Katen, Oregon

[Richard Moore]

The area where the arc occurred is not protected by the main breaker, assuming that this panel is a main panel. It is protected only by the utility fuse which protects the utility transformer....

I won't argue with the rest of your post. You and Jim are probably right about replacement. But...that bus bar lug is protected by the main breaker. Power comes in from the SECs to the main breaker lugs and doesn't go anywhere else until it passes through that "backfed" breaker.