"Any deviation from code is a serious potential problem for your system."
By R. Bruce Wright, CPCU
As we all know, the National Electrical Safety Code (NESC) is the consensus standard adopted virtually countrywide for electric distribution and transmission systems. Not to be confused with the National Electric Code (the NEC), which is the code that deals with building wiring and related issues, the NESC standards cover nearly everything in distribution and transmission systems, from technical installation of specific components to the vertical and horizontal clearance requirements for various voltage lines.
The systems we consult with in our program typically have an intimate knowledge of the NESC requirements (as they should) and virtually every line worker has a working knowledge of the basic clearance requirements for the line loads they work with on a regular basis in their “home” system. Those clearances are the focus of this article.
When a Synebar consultant visits any NHA Power Program member, it is standard operating procedure for us to ask about line patrol activities that focus, in part, on a visual check of the line clearances to verify that they are up to code. This is a basic procedure we look for and recommend as an on-going method to check that the lines meet the NESC clearance requirements, even in the face of changing circumstances. For example, if someone erects a structure near or under an existing line, clearance requirements can be violated. If a township, county, parish, or state should repave an existing roadway, adding a new layer or two of blacktop, clearance minimums can be violated. If weather causes guys to weaken or poles to settle, the resulting “extra” sag can cause clearance requirements to be violated. All of these events and many more that you can recall from your experience actually occur all too regularly and serve as typical examples of why a line patrol program is essential to maintaining clearances at or beyond the NESC requirements.
When we ask about line patrol programs, many times we hear that all field personnel are required to observe line conditions as they travel through the system every day, and that they complete some type of formal report whenever a problem is spotted. This approach is good as far as it goes. Usually this approach succeeds pretty well at identifying any open and obvious defects that crews drive past as they go about their work. It typically results in a written report, a work order, and a paper trail documenting the actions taken.
However, this approach has a couple of significant shortcomings or gaps. For one, it does not provide for any easy way for a Line Superintendent to manage the process. If you were responsible for ensuring that all the lines in a system were looked at over some set period of time, how could you do that with this approach? In fact, you couldn’t, since you have no way to know any particular line was looked at unless there was a problem with it that was reported. Otherwise, it wouldn’t be mentioned. Another issue is that lines near the office get seen by lots of crews every day, while distant lines in sparsely settled areas visited infrequently may go a long time between observations. Cross country lines may never be seen at all by anyone in a vehicle. Finally, this approach offers no paper trail, no documentation, for patrols of lines where everything is fine and no defects are found, which can make is impossible to prove that in fact it was looked at recently in the event of something going wrong.
So why is this such a big deal to us? To answer that, let’s look at yet another example. Imagine that you have a member who is replacing a TV antenna. (With the advent of all digital TV at the start of next year, this type of activity is likely to spike again, just like it did in the days of the CB craze.) Let’s further say he uses a 25’ tall pole for the antenna, and in the process of erecting it he touches a distribution line and is burned. The investigation finds that the line his pole touched was 17’ above the ground, 3’ below the applicable NESC requirement of 20’ above. Now we have a problem. Imagine a jury, seeing this victim with severe, even horrific injuries, listening to the defense attorney arguing that the victim shouldn’t have erected the antenna under the lines, and that in any event the pole would have hit the line even if it was up to code, since the TV mast was 25’ tall and code is only 20’ feet. What do you think a jury would do? I suspect you see the problem. Any deviation from the NESC leaves the door open to finding fault against the system. Any deviation from code is a serious potential problem for your system.
Now, obviously there are more situations that a line patrol program should be identifying beyond maintaining basic clearance standards, but maintaining clearances is certainly one of the major issues. If you don’t look in an orderly, methodical fashion and document your findings, you will find it difficult to manage the process, to know for sure that all lines are inspected, and not have any “negative documentation” or any paper trail covering lines inspected where nothing faulty was found. In other words, you are leaving the door open for the jury to walk through.