Note: comments posted are strictly the opinion of the poster and not necessarily those of Fiber Planners Inc. or any other posters.
Monday, March 22, 2004
Cable TV operator's probable NESC violation causes accident, interrupts power
The National Electrical Safety Code NESC is written by representatives from the power, telephone and cable TV industries to ensure that aerial and buried communications and power cables don't pose a threat to the public or other utility workers.
Cable TV operators violate safety code requirements all too frequently In our work at Fiber Planners, we see cable TV companies violating the NESC on probably 2 out of every 10 poles on any given power line we look at. It costs a lot (typically $3,000) to replace a crowded short pole with a taller pole, so cable TV companies frequently just slap a cable up either too close to the energized conductors or too low to the ground. Georgia Power reported over 10,000 in Georgia alone several years ago.
Today's Olympian has an article showing what happens when a cable TV line sags too low. A truck snagged the line, which then pulled down two poles and three power lines. The pictures show the problem clearly -- this was no oversized truck and is too short to clash with overhead lines -- had they been strung to the NESC clearance requirements. Fortunately, no one was hurt.
One of the pictures also shows why ADSS cable installations can be so damage-resistant The bottom picture also illustrates a point I made last week about ADSS cable installations of the sort Fiber Planners installs. When a pole is pulled over, the very strong metal conductors and the cross-arms of the pole tend to keep any ADSS fiber cables installed near them off the ground and protect them from damage when the pole goes down. The power may go off (because of short circuits), but traffic on the fiber cable remains uninterrupted. Had this pole had ADSS cable on it, it would have survived unscathed.
This is one reason why ADSS cable installed in the power region close to the neutral and the conductors is so much more reliable than the other communications cables installed lower on a pole (and also more reliable than buried fiber cable which is frequently cut by underground construction). posted by Al Bonnyman
Monday, March 22, 2004#