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md2
06-13-2006, 08:45 PM
here is the deal we were transferring a 3 phase 4kv pole with a 3 phase buck...we had just come down for lunch when a 34kv arm up the road gave up and the 34 phases fell on the 4kv circuit that we were working...all our primary taps had been finalized. but just what could have happened if we had mac's(15kv orange insulated jumpers) still in the air and had been right up in there. I know this kinda falls under the act of god thing but it has me really freaked right now, to know that despite the fact that we had done everything right something could have gone horribly wrong.

Koga
06-14-2006, 06:25 PM
you had all your PPE on and everything properly coverd. One shot on the breaker or upstream device of both circits ? If ya did I think you would have been ok.Most of the damage should have been down the road where it fell and the breaker should have tripped out.I could see the phases where you were whipping around momentarily, but I still think if you hit the bottom of the bucket,you would have been ok. But always check those poles on either side of ya before ya go moving phases. Hard call without being there or all the facts.

Koga

md2
06-14-2006, 08:17 PM
the 4kv has only one shot, but we had no restriction on the 34 so it reclosed 3x before it locked out... the crossing was about 10 spans down the road

topgroove
06-14-2006, 09:51 PM
i'm sure this expierence will stick in your head for the rest of your career. was their burnt up equipment in the houses on that section of primary.??

thrasher
06-15-2006, 11:16 AM
There are so many variables here it's hard to tell if everyone would have been okay. If you were in a bucket and touching ONLY one phase and nothing grounded you probably would have been fine (the old bird on the wire scenario). However if you were using something less than class four gloves (which you probably were) and you were making contact with a phase that got energized at 19.9kv/34.5kv and were making contact with some other potential then you could have been hurt. Glad you are okay.

tramp67
06-22-2006, 07:58 PM
My understanding is the 34KV circuit crossed over your 4KV circuit about ten spans away. When the arm broke and the 34KV landed on your circuit, it basically ended up as a phase to phase fault between the 34KV circuit, as your conductors were like someone throwing a log chain (that's never happened, has it?) across the 34KV circuit. If there were any LA's on your line, they should have taken care of any momentary surge before all three conductors landed on yours together.
This is a pretty good lesson on why you should aways work between grounds, and "if it isn't grounded, it isn't dead", isn't it? Glad nobody was hurt, I bet this is something that will always stick in your mind, and keep you aware of the possibility of a freak accident energizing a line. All it takes is one thing to go wrong and a good day turns into a bad day. You can't control everything, therefore you need to work safe and use time proven practices to keep you and your work area safe.
My guess is you would have been fine had you been in the air when this happened, remember to never let your guard down, that's when accidents happen!

DuFuss
07-15-2006, 06:24 PM
I'm agreeing with thrasher here. You'd have gotten a buzz if you were gloving a primary.