Thank you all for your input. As the regulator I have had concerns about using inside wiremen for medium voltage work and have shut them down for the last 2 years until they could show me the following: 1. Medium voltage Procedures 2. Medium voltage training program 3. Necessary tools & PPE They came back and said they are ready to show me their program, training, PPE, and tools but when I looked at what they had, I found that they were not using grounding clusters because they said that 10 CFR 1910.269(n) did not require it if it was “impractical”. I still have them shut down and have been trying to show them that it is practical if they make minor modifications to the elbows during the next site shutdown. Installing ground clusters can be the difference between life and death and should not be eliminated because they are “impractical”. Our local utility linemen have been very helpful and knowledgeable in helping me present a practical solution. I was just using this form to see if there were other ideas out there.
Bull, MV switchgear always need to be grounded, and thier grounding clusters need to be tested and rated for the available fault current on the system they are grounding. You dont just go out and "Get trained up" on MV gear. Many companies require all work done on MV (And some LV stuff like switchgear and transformers) to be done only by a "Certified" company and "Certified" technition or testing engineer. Certified is through NETA or NICET.
Are far as the elbows, any real power system testing company will have the grounding elbows for this type of installation. Another good solution is to install the ball studs for grounding ( AB Chance or salisbury have these). There may be a better solution if I knew mor about the equipment.
In the meantime you can find a Certified" testing company in your area at www.netaworld.org
MV/HV Testing Specialist, "BKRMAN"
Re: How to bleed the capacitance charge off of 13.
#177761 05/11/0803:39 PM05/11/0803:39 PM
I have been around HV enough to be wary of it. It does not act like your typical 480v stuff.
It will reach out and touch you. It will recharge the line you just shut down to nearly the same voltage it was at before you drained it.
Make sure you have the best gear available and take it slow. Personnally, I'd hire GE or a local engineering firm with HV experience to send out a service tech.
I was goin to just read these post and be quiet,but you have some guys on here that have no idea of what they are talking about!!! High voltage WILL NOT reach out and grab you!!! Overhead-It can only "recharge" if there is a immediate source from which it can be "induced",hence grounding. Underground-can be induced or if left ungrounded for a long amount of time (days not hours) can build a capacitance charge.
You have the right idea for correct producure to deal with MV/HV system Many pad mount most case it will have stand off point attachment however with some older one they don't have stand off so we have to make a grounding boot for it so we can able do it in safe manner..
NOTE :: to the rest of readers here please keep it civil if get out of hand with this I will or other Moderators will lock this thread.
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
So I take it you have never heard of MAD (Minimum Approach Distances) and Flash-over distances.
One other thing, tell that to the people that have climbed HV poles and towers without having even got close to the wires and have either been killed or very seriously burned as a result of their actions.
MAD ,Minimum Approach Distance 2-15 kv is 2'1" 15-26 kv is 2'4" 36-46kv is 2'7" I can go on all the way up to 500 kv.
What you don't know is MAD is how close you can get BEFORE you have take protective meassures, rubber gloves and rubber sleeves or "hot sticks". I'm not going to start an argument here,BUT UNLESS you have ACTUALLY ever worked on high voltage under ground or overhead lines you are NOT qualified to tell me how it works!I worked distribution voltages up to 21 kv ,rubber gloved,hot stick, in a bucket truck and climbing poles.I have "BARE HANDED"(work on energized) 230 kv out of specially insulated trucks. I spent four years in school and countless hours on the job learning, I currently run a crew of 4 lineman building and repairing power lines,before that I was a JOURNEYMAN ELECTRICIAN,so I speak with some experience!Oh yeah,, I have an electrical engineering degree too.
Mr.Trumby,you must me confused ,I still firmly stand by my claim that "it" WILL NOT, jump out and grab you.A "crazed" drugged out person CAN climb a power pole and get with in an INCH of the energized conductor and NEVER get electrocuted UNLESS he TOUCH'S it.You HAVE to create a path to ground.If you haven't TOUCHED it you haven't created a path.( You could have a bad insulator,which could lead to tracking,which in that case the pole could be hot,whole different discussion)
Your claim of people getting burned from climbing HV( I've climbed plenty to do repairs) towers is partially correct,as you get closer to the energized conductor(wire)you enter a electro magnetic field,if you get partially into that field you will start to feel a charge called "INDUCTION".That comes from the HV "inducing" current onto you,if you have hold of a grounded tower leg,and enter that "FIELD" you have created a "difference" in potential,if that difference gets great enough it will start to burn you ,just like cooking in a microwave.
Like I said I'm NOT here to start any arguments,,,just get the facts right,,,,,,