I was at the Fire Island Pines yesterday.

While wandering around one of the trails that follows the utility poles between Cherry Grove and The Pines (two towns on this thin little sandbar between the Atlantic Ocean and Long Island) I noticed a T-shaped iron lever attached to the base of the pole. A rod ran up from the lever and then linked to whatever the rats' nest was up on top of that pole.

It looked like a switch to me - seemed like it would probably cut out a section of the power line so that lines-men could do repairs if needed. I wasn't about to move it anyway....besides, I think it was also padlocked.

I've never seen anything like that. You wouldn't have such a thing in New York City....for obvious reasons. Or would this be a sort of circuit breaker?

Also, I noticed on another pole, The Phone Co. had a big tin cabinet attached to it, with an electric meter. As I trudged by, I heard the thing rattle to life, run for half a minute and then go back to sleep.

I took a closer look (couldn't open the box, of course), but I noticed a black tube going to a little metal rack holding about five valve nozzles like the ones on a car or bike tire. More hoses then dissapeared into the sand. I guess this is a compressor for keeping the salt water from leaking into the telephone cables.

Pretty ingenious.

Sven,
Yes, you use the switch to sectionalize a circuit. It is used to make repairs (IOW, we can interrupt the circuit halfway, and energize the other half affecting a smaller amount of customers), altering load (this circuit is overloaded, put these customers on another circuit), or emergencies of several varieties.

Yup, you've got'em in NYC, ya just can't see'em.

I know these things from the Vienna tram system. Of course they're padlocked, but sometimes people do get to open them, usually de-energizing one or more entire tram line for about an hour or even more (them guys aren't that quick finding the break and switching back on). Last February there were some youngsters running around killing lines rather frequently, I don't know if they were caught.

I see these type of switches all over Maine. I keep asking my POCO buddies what would happen if I stopped and opened one of those babies.They just laugh and say get ready for some arcing . They tell me during the ice storm in 98 those things were great help and when they went to shut them after fixing an area, one didn't casually close the switch.

George,
I’ve seen these switches used and they seem very slow.Why are we to open and close large service entrances, discos ect quickly and in a confident manner when the poco's switch is so slow?Just wondering because ive watched a liney crank one like mad and it seemed to only move a about a foot in five seconds and close in a very sloppy fashion.I realize the arc is larger on the break then of the make and that we want a positive engagement so it does not explode.Are these switches de-energized before thrown?

What is the point of de-energizing a switch before throwing it?

I thought that was the whole idea of having a switch...to cut a circuit?

Or at this level is it more of a "fail safe"?

SvenNYC,
I dont no if they are de-energized or not before switching. It’s just the one i saw being used was very sloppy, slow and looked like it would not be capable of handling the load He was closing it and The contact arms were swaying in the wind also the bars almost stopped before sliding into the clips and i never saw an arc.This is a hospital and a few years later the poco came back to install a pulse meter. I didn't want to throw the service entrance mains because if it failed it would be our fault .Instead i tried like hell to get them to throw the pole switch or xformer kiosk and the told me no way they didn't want the liability either. I ended up having to put the generators on load test and shed as much standard power as possible .You see it was an old and odd 600v 3000a FPE switchboard with horizontal fuses that had not been exorcized in 20yrs and parts were two weeks away . Plus the hospital was closing in two years and the old meter was fine they just demanded that we shut down for 3 hrs and install the new meter.He refused throw his switch . When hospital administration found out what the argument was about they wrote a letter and the guy at the poco got reprimanded.Also the pole switch looked like it had two sources(three positions.Maybe they were scared to throw it?


[This message has been edited by frank (edited 09-22-2003).]

We have switches operated by a rod and handle in Britain.

There are quite a few on the 11kV distribution poles in this rural area.

A very classical type of poletop air-break switch is…



It’s important to understand that their load-interrupting capabilities are dependent on accessories furnished with the switch. Some are “isolating only”, meaning they can not be operated under load without damage to the equipment {or operator} and may not even intended to break line charging current. They are rated in the 15-138kV range. Older, lesser used, never maintained air switches are the spookiest.

P.S.: The phoneco box sounds like a air dryer. It’s used to purge cables to keep ‘em dry. Their sound reminds me of an older refrigerator, and they do have hermetic refrigeration compressors in them.

Many older telephone cables here were pressurized with nitrogen to help keep moisture out.

I once saw an article in Four Wheel Drive magazine on how to pressurize all your guages with a small compressor when building the ultimate river fording machine.

I've got a switch like that in front of my house, and there's a bottle of nitrogen chained to a phone pole with aforementioned box above it right down the street...S

Bjarney,
I'd agree with you there, mate!.
Darned things give me the willies!.