retired serviceman

[heberrose]

we had a transmission crew working on a 161kv line 7 I was to do the switching for them(our switching was going to the sub-station calling dispatch & watching to make sure the mods opened all the way. The first day i did this i thought the arc was not going to break. So the next day i took my helper with me to video it. I called dispatch told them i was ready. the switches came open & the arc followed & did not break. I told dispatch it did not break, no response, so I HOLLERED IT DID NOT BREAK you better close or your going to burn down the station. The dispatcher said i'm trying to close it. he finally got it closed & i asked him what are you going to do now. He said i'm going to talk to our engineer. In a few he calls back & says if you are ready we are going to try again. so he opesn it & the biggest arc i have ever seen started but then it broke with a bang like a 12 guage shotgun. I asked my helper why he did not run. He says well i looked at you & you just stood there so i thought it was ok. I told him if he ever sees a fire like that again RUN. Heberrose

[wtdoor67]

We've all done it I suppose.

However I once talked to a guy who had attended a short seminar on switching, especially in Subs.

He said the theory presented to them was to stand pat in case things went to hell. The engineer/presenter said that running during a close encounter with a ground fault that you presented a better target for ground gradient faults as your legs would be extensively spread, whereas standing and covering your head was probably better. Easier said than done though.

[MI-Lineman]

We've all done it I suppose.

However I once talked to a guy who had attended a short seminar on switching, especially in Subs.

He said the theory presented to them was to stand pat in case things went to hell. The engineer/presenter said that running during a close encounter with a ground fault that you presented a better target for ground gradient faults as your legs would be extensively spread, whereas standing and covering your head was probably better. Easier said than done though.

You mean "step potential?" I think ya MIGHT not get nailed by that but if ya had a phase to phase you'd be a crispy tater tot!:eek: I'd probably run like hell and deal with cleanin out my shorts after if I were that close to it!!:o

[wtdoor67]

No the way I understood this was if you ran you exposed yourself to step potential. As it radiates thru the ground it creates areas of different potential. If one foot is in an area of different potential as the other, then that creates an ideal path of current, up one leg and out the other.

People who are killed by lightening are killed by step potential I believe. I don't believe the lightening bold hits them directly as I think they would be burned to a crisp, due to the high voltages involved. Sometimes they are burned and survive but I don't think they are exposed to the full potential of the lightening bolt.

[MI-Lineman]

No the way I understood this was if you ran you exposed yourself to step potential. As it radiates thru the ground it creates areas of different potential. If one foot is in an area of different potential as the other, then that creates an ideal path of current, up one leg and out the other.

People who are killed by lightening are killed by step potential I believe. I don't believe the lightening bold hits them directly as I think they would be burned to a crisp, due to the high voltages involved. Sometimes they are burned and survive but I don't think they are exposed to the full potential of the lightening bolt.

That is right! That's what I was sayin! Your engineer or what ever you call him was sayin NOT to run because of the "step potential" hazard when the arc went to ground but that would be hard to do!:o I meant "you wouldn't get nailed if ya stayed put" but that would be hard!

As far as lightening I'm not to sure about that? I've never heard step potential used when explaining a strike ALTHOUGH I believe MOST cases are probably that! My Dad got hit twice!:eek: Once in a Boyscout camp and again on a tractor in a field! NO not direct hits I'm sure!;)

[cololinehand]

step potential, but if you are running both feet shouldn't be on the ground at the same time should they?

[MI-Lineman]

step potential, but if you are running both feet shouldn't be on the ground at the same time should they?

HUH?:eek: GOOD POINT!:rolleyes:

[glennk]

If your stuck you are suppose to take both feet and jump out of the area that way there is no difference in current the farther you jump out the better chance you have> ( So I was taught there were no live demonstrations:D)

[wtdoor67]

Never studied a slomo of a running man in a sub station. Just a blur.

I believe some of those Ninja's could leap clear with out touching the earth. Just make sure you leave the sub gate wide open. Course that's against the safety rules. Damned if I know what to do.

[Trbl639]

Awful hard to think like that, when the rabbit in ya says......Run!!!

Was told the keep the feet together and hop routine......only time I remembered it, was when we were escorting a house move...house mover took the wrong ramp and got hung up in some 115KV before we could stop him, and one of his men tried to jump on the truck....was 'guarding' the downed man, to keep him from getting up and going back to the truck, and keeping the driver in the truck..wasn't moving, but it was sure as hell hard to keep from it everytime the 115 breaker operated and the Dragon bellared and more tires on the rig blew up......BTW the guy made it!!!!

Danny, we were helping the base linecrew one day, met them at the sub, and paint shop had just finished painting an OCB and we ready for it to be made hot.......just as we got to the sub, one of the Base linecrew hands closed the breaker.......they had left a set of grounds on, right outside the sub, on a cap pole...........we didn't seem, but we did see him try to make a new gate in the fence....3 times!!!