3 phase out of phase

[James D. Clark]

This is about 1 mile from me.

[hankj]

What in the name of all that's Holy IS that?

Hank

[James D. Clark]

It's along one of the streets I take and I also take my walks by it. It's part of the power distribution lines along the street. Residental, schools, churches, golf coarse, fire station and a couple of businesses. It looks like some kind of a switch that has the 3 phase lines going off of it out of position for phase. Why? Don't know. It's the first one I've seen. Maybe one of our electrician pros can tell us.

[ohmthis]

In all the years in the electrical field I have never seen that before. Question.....Is that middle phase taken to ground? Where does that lead go to? I wonder if it is a high leg delta sytem that they are trying to bleed off with a huge resitor. I can't tell very well from the picture what is going on. Sorry!

[Sandy]

Looks more like a rotary disconnect rather than a knife. Notice the knuckles in the tubing. Top wire should be the small trashy nuetral for a multi-grounded nuetral system. Possible they 'rolled' the grounded nuetral to the top just for that pole and the disconnect, it normally rides below the rest. More than likely what the sign is trying to indicate is that whatever lead you were following is out of position on that pole.

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[Old Man Stick]

It might not be a true 3 Phase run there. I know my street here there are 3 differnt legs running through but there not persay 3 phase. The only think that I know for sure is it really pisses me off to see the street light in my driveway all lit up and my house without power!

My house is on one leg, my street light is one another and the house acrost the street is on the 3rd leg.

Other then just a pure guess there I dont have much of a idea on that one.

Loosk scarry thoe !! LOL

[James D. Clark]

The sub-station is one of those "looks like a small house but its's an enclosure" but it hides the transformers. It is two blocks from me on the corner of the golf coarse. The sign is about 1/2 mile from there. I'll see if I can trace the lines. There is some major high lines intersecting there. When a breaker trips it sounds like a bomb going off.

[ctrpunch]

That's an insulator for the operating handle on the three phase group operated disconnect switch on the pole. It's there so you dont get zapped.

[Terry Lingle]

What probably has happened here is that this feed was phase rotated cba ratherv than abc so all users on this line have connected there motors accordingly but now it is not practical to correct the problem , The sign is to allert the utility workers to the situation and prevent problems when they worl on the system .
Terry

[James D. Clark]

The sign is on the pole where the wires go from a tiangle type wire arrangement to the cross bar with a ganged switch then back to the tiangle transmission line. There must be some kind of rule of hand for three phase transmission lines and this pole has the wires reversed.

I took some more pictures today. The one shows the switch. The other shows the triangle arrangement of the wires with a drop to a buried cable feed. The triangle setup was all the way along the line except for a few poles like the one with the switch. Except for a few transformers all the drops were to buried cables with the 3 phase to feed neighborhoods and businesses.

[Amana]

The device in question is called a Gang-operated air break switch. It is simply a three-phase manually operated switch that is operated by a lineman from a handle at ground level. The rod running vertically down the pole runs between the operating mechanism at the top of the pole to a handle on the bottom. That is the reason for the insulator in the operating rod, to protect the lineman (and the general public) if something breaks at the top and energizes the rod.

The sign with the Out of Phase note probably is an indication that the circuit conductors on each side of the switch do not line up (Phases A -A, B-B, etc.). Sometimes systems end up this way just because of the way the system grew, maybe even miles from this location. Sometimes it could just be poor (or no) planning. Note that the switch is in the open position. The sign tells a lineman that he cannot close this switch with both sides hot since the conductors are out of phase. This switch can only be closed when one side is dead. This switch is likely used only for a backup tie to transfer load from one circuit to another.

The conductor attached at the very top of the pole is the circuit neutral and is also used as the messenger to support the phase conductors on non-metallic diamond shaped spacers. This is called spacer cable type construction . This is not as common as wood crossarm type construction.

Might as well say hello since this is my first post. I have been a lurker here for about two months. I am a consulting electrical engineer. I mostly do high voltage distribution engineering for rural electric coops and municipal electric utilities.

I am a very amateur hobby welder. Just do the typical homeowner d-i-y stuff. Have a Miller Thunderbolt AC/DC stick welder and a HH175 (Christmas present from the wife and sons last Christmas). I am a very lucky guy.

Great board. I have learned a lot already and expect to learn a lot more.
Amana

[hankj]

Amana,

Welcom aboard!

We need a guy with your expertise. Lots of posts here about electical systems; plenty of talk about wye, deta, open delta, derived third phase - heck, you'll be right at home, and we'll appreciate your input.

Hank

[Sandy]

I mostly do high voltage distribution engineering for rural electric coops and municipal electric utilities.

You probably get to deal with some of the older REA (RUS now) type construction then ???

Anyway, welcome have fun.

[James D. Clark]

The device in question is called a Gang-operated air break switch. It is simply a three-phase manually operated switch that is operated by a lineman from a handle at ground level. The rod running vertically down the pole runs between the operating mechanism at the top of the pole to a handle on the bottom. That is the reason for the insulator in the operating rod, to protect the lineman (and the general public) if something breaks at the top and energizes the rod.

The sign with the Out of Phase note probably is an indication that the circuit conductors on each side of the switch do not line up (Phases A -A, B-B, etc.). Sometimes systems end up this way just because of the way the system grew, maybe even miles from this location. Sometimes it could just be poor (or no) planning. Note that the switch is in the open position. The sign tells a lineman that he cannot close this switch with both sides hot since the conductors are out of phase. This switch can only be closed when one side is dead. This switch is likely used only for a backup tie to transfer load from one circuit to another.

The conductor attached at the very top of the pole is the circuit neutral and is also used as the messenger to support the phase conductors on non-metallic diamond shaped spacers. This is called spacer cable type construction . This is not as common as wood crossarm type construction.

Might as well say hello since this is my first post. I have been a lurker here for about two months. I am a consulting electrical engineer. I mostly do high voltage distribution engineering for rural electric coops and municipal electric utilities.

I am a very amateur hobby welder. Just do the typical homeowner d-i-y stuff. Have a Miller Thunderbolt AC/DC stick welder and a HH175 (Christmas present from the wife and sons last Christmas). I am a very lucky guy.

Great board. I have learned a lot already and expect to learn a lot more.
Amana

Amana; Welcome aboard. Glad to have you explain the reason for the sign. Most people don't think about how they get their electricity. They only miss it when it's gone. You don't admit to have anything to do with this system? You don't by chance live in the colonies?

[Amana]

I live in Oklahoma City now and mostly work for the coops and muni electrics in OK, KS, and TX, with the occasional job all over the country. My employer also does a lot of work for the federal government and DoD.

Before this job, I worked in Kansas City and also worked for several coops in Iowa and Illinois. I never worked for Cedar Rapids but I have spent a lot of time in the general area.
Before that I worked in South Bend, Indiana. Several of the muni electric systems in Indiana and Michigan used spacer cable construction. I have designed a dozen or so such projects in years past. The munis like it because you can run it right through the trees with very little clearing and it requires a narrower right of way than open wire construction. Also it is easy to get a double circuit on a pole. It is almost exclusively used in urban situations, never rural.