I was going through the code violation section and the comments on abandoned wiring and thought I would relate the story of a refit job I worked on.
Several years ago a company I worked for moved to a 'new' plant. It was an old automotive plant that had been abandoned since the previous company moved to Mexico.
Before the Electricians for the company arrived a crew had been sent to move in and place the heavy equipment. The first thing they did was turn on every breaker they could find. This would have been fine except for the fact that when the previous company moved they disconnected the wires from their equipment and proceded to wrap the wires, complete with exposed leads, around whatever pipes or structural members were around.
Several breakers blew completely out of the panels, prompting the movers to call the electricians. Who'd have thunk it?
At this time the company did not want to pay overtime so the electricians were told to wait till Monday and the movers were told to turn off everything. That weekend one of the pipers decided to get a head start on the new compressed air lines. After turning on all the breakers he grabbed a pre-existing air line that had 277 volt wires wrapped around it twenty yards away.
His hospital bill would have covered the overtime.
Subsequently the Electricians began a four month process of tracing down over 1500 circuits whose wire numbers, due to grime from plastics processing, were no longer legible. The circuits had also been ran in all red wire. 120 included. We took down several hundred feet of busbar with missing doors or exposed ends, and replaced lighting in the lower floor of the mezanine. This was due to the bathroom sewage pipes on the top floor leaking into the flourescent lighting below. We began by drilling holes in the plastic lens cover to drain the water that had pulled there.
Eventually we removed twenty-seven tons of unused busbar, wiring, conduit, and piping. We replaced the existing wiring with new clearly marked wiring and labeled every recepticle, and device with the breaker location.
In the end, after selling the scrap, we actually made money on the effort and made the factory a much safer place for us and any future users.