Voltage Sensor with dry contact (no physical wire contact)

[Natfuelbilll]

Funny, I was looking for exactly the same type of non-contact device as Chris. My application is a little different though. I need to know when an emergency generator is running due to a utility power failure, as compared to when it is being run for preparedness testing. I have to monitor the line side of the breaker (generally the service disconnect) to make this distinction. I need to record the run hours for each of these conditions. I see NEC 2008, section 230.82(2) permits METERS and 230.82(4) permits instrument transformers. Most of my breakers are Square D. I have to do this for 140 generators, so it will be good to get the best deign figured out. Sure like that non-contact voltage detection idea....

I also want to thank you guys for your discussions on NEC implications and how to do this monitoring.

Bill

 

[gar]

131230-0812 EST

I can probably design a non-contact AC 60 Hz voltage sensor with about 1% accuracy. This would be about 4" long and start at about 3/4" diameter for small wire. The wire being sensed would pass thru the probe center. Primarily this would work with circuits referenced close to earth ground, but could be designed for differential measurement. But this would take a lot of space and it would not be inexpensive. I don't see much real need or demand.

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[Smart $]

F.... Sure like that non-contact voltage detection idea....

131230-0812 EST

I can probably design a non-contact AC 60 Hz voltage sensor with about 1% accuracy. This would be about 4" long and start at about 3/4" diameter for small wire. The wire being sensed would pass thru the probe center. Primarily this would work with circuits referenced close to earth ground, but could be designed for differential measurement. But this would take a lot of space and it would not be inexpensive. I don't see much real need or demand.

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There's a unit already on the market... but no dry contacts and battery operated. May not take much to modify...??? I found it when looking for a device to let me know when I got power back after utility failure and running on generator with manual transfer...

http://www.reliancecontrols.com/ProductDetail.aspx?THP108