Illustrated Catastrophes

Jun 1, 2006 12:00 PM, By Joe Tedesco, NEC Columnist

As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without criticizing anyone or any product, the following scenarios present us with serious safety questions.

All references are based on the 2005 NEC.

Taking Perfect Aim. Karl Darby, owner, Darby Electrical, Stockton, N.J., found this installation at his new next door neighbor's house. “Once the house was finished, and we headed over to meet the new neighbors, I spotted the electric service. As you can see, it appears the cable TV installer drilled a hole from the cellar, out through the siding, and right through the service lateral conduit, apparently without hitting an energized conductor. Amazing! The best part is they neatly caulked the penetration after installing their coax. Also note the grounding wire is disconnected.”This work shows a clear lack of proper training, which could have easily resulted in a fatality. This installer was most likely unaware of what could have happened to him if the drill penetrated the energized conductor. Lucky for him, it probably penetrated the grounded (neutral) conductor. The NEC doesn't list a specific rule for disconnecting the lateral with service entrance conductors in it.

Burning Down the House. David J. Delany, P.E., senior electrical engineer, FreemanWhite, Inc., Raleigh, N.C., ran across this arrangement in a friend's 20-year-old house. “I found it like this when I removed the panel cover to install a new breaker for him. I don't have a picture of the meter socket, but it was just as burnt up. It looks like a few things caused this problem. The panel is located in a utility room attached to the house. The room is accessed via an outside door, which is left open at times, allowing damp conditions at the panel. Combine this with aluminum conductors and loose connections and the result is overheated conductors. Luckily, the house didn't burn down before the equipment was replaced.”

Remember to torque those connections as required by the instructions on the panel, and watch out for those long trim screws. The screw on the right top originally penetrated the hot phase conductor and helped cause this damage because of the missing main bonding jumper.

Found a Code Violation? E-mail your photos to Joe Tedesco at joseph.tedesco@yahoo.com.