check this Pic

[iwire]

Pierre,

Rewire said the neutral was poorly taped and arced against the cover.

If indeed it was the neutral making that much of a mark I would be very concerned that the neutral on the supply side is open or has some high impedance connections.

A neutral will generally not leave a mark when shorted to grounded metal.

 

[don_resqcapt19]

They brought a four wire system from the building service panel in the junction box they spliced the neutral and ran it out to the dock they then took the neutral uo to the disconnect with the line side. The neutral was poorly taped and arced on the cover

Why did the neutral arc? In the absence of an open or very poor connection on the neutral, I would not expect an arc. The only voltage available to drive an arc to a grounded enclosure would be the voltage drop on the neutral. Yes, there would be a parallel path, but I would not expect to find visible arc damage.

 

[ibew441dc]

Originally Posted by ibew441dc View Post
Pierre,
Rewire said the neutral was poorly taped and arced against the cover......

If indeed it was the neutral making that much of a mark I would be very concerned that the neutral on the supply side is open or has some high impedance connections.

A neutral will generally not leave a mark when shorted to grounded metal.

......Although unintentional, This conductor was making a poor connection, with probably some significant impedance, causing a good enough voltage drop to start heating up.......resulting in Objectionable Current flow.

There are a few plausible scenarios that could easily result in arcing of this magnitude from the (what looks like to me Aluminum Utility Grounded Conductor, that is spliced).

1)As you stated an open neutral would be very likely.....
2)As we both implied the neutral has too much impedance....
3)Another definite culprit would be induced lightning and/or high voltage transient, that would definitely do it .

 

[RUWired]

This is the J box were they spliced the neutral to feed the dock and then to disconnect the black spot is from the a poorly taped lug

Thats a good example of a 314.28(A)2 violation.

 

[wawireguy]

I'm looking at this thing and I don't see the EGC brought in with the feeders to the disco on the doc. Looks like it comes in from a KO on the bottom. My guess would be that the neutral is bonded to the can and acted as the EGC in a fault condition and that the cover on the shore was a better path than the neutral. I might be way off on this though?