Optical Sensors
Does anyone have any experience with optical sensors for detecting arc flashes? I've seen the brochure for SEL-751A. Are there other vendors?

An ABB paper on the subject:
http://www05.abb.com/global/scot/scot22 ... 756426.pdf.

All the big OEM's have a similar product, and they are effective mostly in MV systems. Watch for a new one soon that senses if people are in the vicinity of the gear.

AF sensors

We have a VAMP system in use on one of our loadcenters. It is a reasonable unit but does not perform to its full potential due to the inability to trip upstream into the 13.8 KV switch. This isn't because the vamp isn't capable - it's because the 13.8 KV switch is a couple thousand feet away and I haven't installed the dedicated infrastructure for tripping. I will be doing some Schwietzer 751A relays next year. I like them far better than the VAMPs . The only downside to this type of technology is that you are always stuck with your slowest time to clear. Old breakers open slowly - putting an optical AF relay on a 100 ms breaker is probably money poorly spent. Better to upgrade the breaker!

Canuck01,
Thanks for your info, especially about putting an ultra fast relay on an old breaker.

Look on the IGARD website.

Vamp, ABB, and UTU have a long experience of applying optical sensors. There must be tens of thousands of installations worldwide. You can choose if you want "light only" or "dual-sensing" operation principle.

"...around 150.000 arc flash sensors in use"
http://www.vamp.fi/Default.aspx

Optical sensors

I have tested the ABB REA 101 and the SEL 751A. Will be installing each of them at sites in the near future. I have the SEL 751A on my desk right now for testing.

Cannot do a full test on a desk, but I can test the reaction to flash; camera strobe does nicely. But no CTs on my desk so I cannot test the current portion of a simulated arc.

SEL 751A update

Still working on this relay on my desk. It has a lot of capabilities, with associated complexity. I need to not over-complicate things.

Documentation is good, aimed at utility electrical engineer, which I am not. A good way to be exposed to a "new to me" discipline.

Right now leaning toward using only the point sensors for existing switchgear. Smaller coverage but much easier installation anticipated.

Another consideration, this installation is for mobile offroad equipment with 6 Gs or more of vibration. Unsure the bare fiber will survive the continual flexing and temperature cycling.

Stand-alone solutions

AB P.E., you seem to have an exotic environment. Why don't you try Vamp's stand-alone devices? E.g. arc-flash protection equipment designed for wind power plants has to be able to withstand vibrations.

Vamp

I have looked briefly at the VAMP, it has a flexible, rugged fiber system. Our customers are specifying the SEL-751A. Plan is to use SEL point sensors only.

The SEL has waveform capture and event recording, VAMP does not. Typical product trade offs, complexity vs simplicity.

SEL support, is nearby, I am in N. America and so is SEL. That is often an advantage vs. a Europe based supplier.

Pricey, but designed and used on Military Nuclear Submarines and Aircraft carriers.

http://www.drs.com/products/control/ADACS.aspx