My own event

View previous topic View next topic Go down

My own event

Post  rcdallas on Sun Jul 22, 2012 3:56 am

I'm sharing this with ya'll and in return I ask that there is no over analyzing nit-picking to come of it.

Working trouble today with outside temp @113; been quiet all day till 1500. Start off with transformer out; CSP. One thing I learned when I first started is with a CSP put your ear on the pole to see if it hums; if it doesn't the internal fuse it out or your primary is ka-put.

Sure enough transformer is dead; back lot and a real pain the rear to get to.

Call the crew and put it in their hands as I had more trouble. After a little while I get a call from the crew foreman if I'm caught up to come back and give them a hand.

So I go back and what they had done was to leave the failed pot on that pole and install a new one on the next span over due to customer obstacles (i.e. people will build a deck over a padmount around here). While the other Journeyman was working the wood installing the transformer I was to go work the pole with the failed transformer and cut the leads--primary and secondary.

I get a shot gun stick sent up and start to remove the hot line clamp; get about an 1/8th of a turn and the energized primary came down towards the other journeyman.

The line side of that wire was still up on my pole; the de-energized side is what fell towards the other journeyman.

If it would have been the other way around--the inevitable. I don't think rubber gloves/sleeves would of helped out in that situation. Wire was 4 ACSR. Here tap saddles/stirrups are not used; clamp directly onto the conductor itself.

Being about 10' below the primary I couldn't see anything out of the ordinary to indicate any hazards with the clamp. It was very fortunate we all walked away from it.

Moving forward when in a situation like that to have all clear both sides as the unexpected can and will happen. Old hard drawn copper I expect to break but ACSR...guess that clamp was never tight to begin with.....


_________________
From 120 volts to Lightning Bolts - IBEW 220
avatar
rcdallas

Posts : 396
Join date : 2012-01-29
Age : 37
Location : DFW

Back to top Go down

Re: My own event

Post  lewy on Sun Jul 22, 2012 7:10 am

We put stirrups on all of our aluminum conductors no matter the size if we are making connections with a live line clamp. With aluminum it does not matter how tight the clamp was put on you will be damaging conductor under the clamp, you should be using stirrups on all your aluminum. As far as # 4 they want us to check it real close before we work it live.

lewy

Posts : 28
Join date : 2012-04-08
Location : Ontario Canada

Back to top Go down

Close call

Post  hotwiretamer on Sun Jul 22, 2012 11:28 am

I'm glad it was just a near miss, as I'm sure you are too!

We use stirrups on everything also. #4 acsr is scary with stirrups though because usually your stirrups range from #4 to 4/0 so the guy before you better make damn sure it is sitting in the grooves corectly. Sometimes it's tough to make sure it is tight because of the flexibility of #4.

Good post Randy, I will share with the line dept. here as a reminder!

Again, I'm glad everyone is a-ok.
avatar
hotwiretamer

Posts : 213
Join date : 2012-01-31
Age : 56
Location : Arizona

http://www.bellsellshavasu.com

Back to top Go down

Re: My own event

Post  topgroove on Sun Jul 22, 2012 12:28 pm

Funny thing about aluminum. the very minute it is exposed to oxygen a very thin, invisible layer of aluminum oxcide developes. That oxcide layer is what actually protects the aluminum from corrosion, unfortunatly it also acts as a resistor. I've watched plenty of lineman simply make that connection without bothering to clean the conductor. With a hot line clamp its even worse, usually the jaws are a tinned copper or alum alloy with a brass eye... different metals causing galvanic reaction. Lineman slap those things on without ever wire brushing the conductor and too many times the conductor is never perfectly seated in the groove. That connection will sit there year after year heating up, slowly eating away at the aluminum and making it brittle. Its a trap waiting to happen... Thats why stirrups were invented. If the connection fails let the stirrup burn. In this case the clamp was the only thing holding the corroded alum. together

What a perfect experience to file away in the memory bank. Next time, I'ld be tempted to tell that foreman your tied up on trouble and won't be available for hours. Let the guy strap his hooks on and isolate it his damn self. who knows... Maybe that crappy connection helped shorten the life of the transformer. Maybe the thing to do in cases like this is to De-energize the primary and cut it with hot stick cutters rather than un-screw the clamp with a shotgun.

Not second guessing a thing cause I would've done everything exactly like you did RC
Thanks for sharing this! This is the kinda stuff lineman should be kicking around. Who knows stuff like this could save someones ass next time.
avatar
topgroove

Posts : 428
Join date : 2012-01-29

Back to top Go down

Re: My own event

Post  Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum