What are these?

[KentAT]

The neighbor of the plant I work at tells me she saw a steady flashing yellow light in the area of where our plant's 12.6KV aerial service attaches to the POCO at the highway. Since it was foggy, it flashed like a bright beacon and lit the area up.

I looked up at the lines today, and I saw that each phase has a device attached on it. They are little roundish things, one per phase, about 10-15 feet down our lines away from the tap. They don't appear to be connected to anything.

My coworker also said he also saw it flashing that day.

Any ideas?

I will post a pic tomorrow.

Kent

 

[Hv&Lv]

Navigator fault indicators. They are wonderful for locating trouble quickly.



Check for signs of trouble on the load side of these. They blink for a reason.
May want to let the PoCo know. The batteries could be getting low.

http://www.powerdeliveryproducts.com/pdffiles/navlmcat.pdf

 

[Open Neutral]

As I read it, they reset when the current goes higher.

If a higher peak is established within 72 hours the FCI will reset trip response to the new peak load. After 72 hours, the Navigator LM re-samples load current and sets a new trip point according to measured peak load current.

So when DO they alert?

 

[dicklaxt]

As I read it, they reset when the current goes higher.

If a higher peak is established within 72 hours the FCI will reset trip response to the new peak load. After 72 hours, the Navigator LM re-samples load current and sets a new trip point according to measured peak load current.

So when DO they alert?

Good question,I did a little digging and the answer ay be here

dick

http://www.powerdeliveryproducts.com/pdffiles/operatingguidecomplete.pdf

 

[KentAT]

thanks.
these are the pics

 

[bob]

Those appear to be fault current indicators. If there is a fault, it will exceed a predetermined amperage and cause the device to indicate a fault.

 

[Open Neutral]

And thus useful at a T, to grok which leg brought down the applecart. Although I suppose if they were spaced along a long feed, they would quickly help segment the problem.

There's a similar product called a Power Donut that reports current back vial a cell data link.

Wonder what the relative prices are?

 

[Hv&Lv]

And thus useful at a T, to grok which leg brought down the applecart. Although I suppose if they were spaced along a long feed, they would quickly help segment the problem.

There's a similar product called a Power Donut that reports current back vial a cell data link.

Wonder what the relative prices are?

They are used all the time spaced along feeders. There are tempoprary indicators such as these:http://www.hfgp.com/fb-catalog/files/assets/basic-html/page124.html for finding faults that aren't easy to find such as a bad distribution arrestor, or a bad pot. They can be installed with a shotgun stick or a long stick. These are basically amp indicators, they trip at a set amperage. If you have a line that is pulling 150 amps, a 100 amp fault indicator will trip just because of the load.

The ones in the picture are adaptive trip. They monitor load and trip on a steep increase in current rather than a slow increase. They are generally placed at taps where protection coordination is difficult or impossible.

 

[Open Neutral]

Interesting. I can see it would not be difficult to detect the enormous current spike of shorted line, vice a 150% overload.

I infer a shorted arrester does not just spit fire and explode as I'd a thunk?

 

[fmtjfw]

Interesting. I can see it would not be difficult to detect the enormous current spike of shorted line, vice a 150% overload.

I infer a shorted arrester does not just spit fire and explode as I'd a thunk?

Shorted arresters sometimes do explode.

They may have a blank as part of the ground lead assembly. The lightning or surge would "dissipate" to ground through the arrester, then if it shorted out rather than going back to its normal non-conducting state, the current would warm up the blank and blow the ground lead off, to prevent grounding out the line.

If you see an arrester with was much insulation between the mounting and the ground lead as between the mounting and the hot lead, that is the reason.

 

[Hv&Lv]

Interesting. I can see it would not be difficult to detect the enormous current spike of shorted line, vice a 150% overload.

I infer a shorted arrester does not just spit fire and explode as I'd a thunk?

Sometimes the surge isn't enough to ignite the charge, or the charge gets wet and doesn't work. I have seen many that have failed that are impossible to distinguish from new ones until they are tested.