Arc Flash protection

[Arevaengineer]

I needed some expert comments that is why im sharing this information.
There is a product in the market called intelligent light information system. It is installed in the switchgear in busbar compartments and individually in each CB compartment to protect from internal arc.The smallest of arcs are detected before a catastrophe and tripping signal is given to the cicuit breaker in 6 ms.
Has anyone come across such a product? Will it work as a backup to the Protection relays or the protection relays will become backup protection after its installation.
Cheers

 

[wbd]

Not exactly sure what an intelligent light information system is but it sounds similar to an arc flash detection relay from ABB that I have used.
The relay is an ABB REA 101 and uses fiber run thru the breaker cubicles to detect a flash. It is used in conjunction with a current setting, so for the relay to trip it would have to see a flash and a current > normal. The relay will actuate in 2 ms.

 

[dithomas]

I have not applied the ABB device but had it demonstrated for me last month. It functions as wbd described.

In my other life as an ABB service engineer I started up some 15kV switchgear with the older version of this device. I understand this device has been used in Europe for some time.

 

[slavag]

Hi .
In additional check VAMP relay site, a very intresting new solutions for arc flashe protection, but base is, as Wbd described.
both of devoces operated in time about 7ms.
Good Luck.
Slava

 

[busbar]

Schweitzer Engineering also has optical arc-flash detection products.

http://www.selinc.com/media/arcflash/arc_flash_testing.php

 

[Maak]

I believe VAMP has been on the arc-flash protection market more than 10 years, the first years with a different name.

For special purposes both VAMP and ABB sell arc eliminators that can extinguish the arc within 2-5ms. With conventional optical sensing based protection the arcing time is the sum of the relay operation time (e.g. 2-15ms) + CB operation time (e.g. 50-90 ms).

In addition to speed, optical sensor based protection provides selectivity, especially when point sensors are used.

 

[ScottyUK]

Here's VAMP's web page:

http://www.vamp.fi/english/products/arcprotection.html

I can't find anything in their literature which suggests that they can clear an arcing fault in 2-5ms, but arc detection and trip initiation is quoted as 7-10ms. I don't know of any breakers capable of clearing a fault in 2-5ms, or even close to it.

Have you got any reference material on how they (supposedly) achieve such rapid fault clearance?


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If we learn from our mistakes I'm getting a great education!

 

[davidbeach]

I don't know what Vamp might be proposing, but the fastest way of eliminating an arcing fault is by shorting it out with a bolted fault. High speed ground switch to short all the phases to ground, no more arc.

 

[jghrist]

I don't know what Vamp might be proposing, but the fastest way of eliminating an arcing fault is by shorting it out with a bolted fault. High speed ground switch to short all the phases to ground, no more arc.

Is a high speed grounding switch faster than a 3 cycle breaker?

 

[ScottyUK]

A fault thrower? I can't imagine it being much faster than a breaker, although on a low level fault an arc detection relay and fault thrower might be faster than waiting for a protection relay and breaker. Direct tripping of the breaker is probably just as quick if the detection relay and the breaker are local to each other - I always thought fault throwers were used when an inter-trip was impossible or impractical?


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If we learn from our mistakes I'm getting a great education!

 

[davidbeach]

I've never seen it in actual use. The first time I ran into a demonstration of optical arc detection, that company was using a fault switch, claiming that optical sense plus fault switch time was less than relay time, let alone breaker time. Without a bus lockout to trip, too much switchgear doesn't have a bus lockout (or bus diff for that matter), there is always the issue of what to trip; there may not even be a main breaker. Lots of industrial stuff goes in for the lowest possible installed cost. I also seem to recall ground switches being used/offered on a line of 15kV class GIS that I looked at briefly for one project.

 

[lefty51]

We actually had a rep. come in, from ABB today, for an arc flash summary he did for us. He did mention the above device. Apparently its a fibre optic cable, which is run throughout the area to be monitored. There is no clear plastic covering on it, so it has to be run in an area that protects the fibre optic. This ties into a relay which is controlled by the fibreoptic. Thats about all I know at this stage of the game.

 

[stevenal]

The Vamp system described at the last WPRC was indeed a device that short circuited the fault. Instead of a grounding switch, I believe it was a high speed solid state device.

And the optical sensor could be worn by a worker.

 

[waross]

Sounds great for the workers in the area of the original fault. Somewhere on the system something must now clear a bolted fault. I don't want to be close to that device. It is no consolation to the next of kin if the enquiry determines conclusively why a device failed to operate as expected.

Bill
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"Why not the best?"
Jimmy Carter