I’d like to get your thoughts on the best grounding practices for overhead line structures equipped with surge arresters. My understanding is that surge arresters should have the shortest possible path to ground via a dedicated ground wire. Additionally, other pole-mounted equipment (power...
Can someone point me to the industry references for the typical outage rates for overhead powerlines? I am performing the reliability assessment study for our distribution lines and would like to have a reference to benchmark against.
Is there any merit to conduct HI-POT on the autoreclosers during periodic maintenance? Some vendors maintenance manuals recommends it and some leave it for users to decide. Our challenge is most of our reclosers are mounted on the poles so conducting Hi-POT on these reclosers is bit of...
Thanks for the suggestions everyone. I guess what I was trying to ask if there is a merit to do the periodic ground resistance measurements for the structures like every 5 years or so. Visual inspection would able to identify any missing ground links due to theft etc. However, things like change...
Most of our steel poles have concrete footings. We have some old wood poles in our systems, which are directly buried. The measured footing resistance was above 100 ohm on affected structures.
We are not a utility, but we manage a large network of distribution and transmission lines that feed critical loads. Recently, we experienced some lightning-related outages on our 34.5kV circuits. Upon investigation, we found that the footing resistance of the structures was quite high, leading...
I recently got in debate with a coworker on the right way to connect the surge arrester across the terminal of the equipment it is suppose to protect. I have attached a sketch for both options which came under discussion. To me both options are electrically same with option 1 offers a shorter...
Anyone here with the experience of using arcing horns on distribution voltage (35kV) overhead Powerline insulators? We have one old line which has ceramic insulators with the creepage distance not suitable for the area, so we are evaluating the option to replace the insulators with the polymer...
Hello all..... we have 13.8kV distribution line which runs near the costal area and we recently experienced few flasover where the inusulator show arc marks on the top shed and the bottom shed only. Installed insulators are composite type with silicon rubber shed and 40mm/kV creepage distance...
I have seen guys doing the conductivity test by shorting the three phases together from one end and then using insulation tester MEGGER to apply 5kV DC between two phases and observe the reading.
Hello Everyone.. what are the typical re-commissioning electrical tests for overhead powerlines? I understand for long distance HV (230kV and higher) you would normally perform phase sequence/rotation check, sequence impedance tests, conductivity tests and footing resistance tests. My question...
Hi All..... We have two old 115kV line running parallel to each other with insufficient clearance between each other. During windy season, we get outages on these lines as conductors of one line come in contact with the structures of the other line. We are evaluating options to fix this issue...
Hello all...... We have a situation where we need to load ACSR conductor in 120-130 deg C range. I am trying to figure out how long (hours, weeks, months?) a conductor can be operated above the normal operating temperature before aluminum starts to anneal and conductor strength gets impacted. If...
