Electrician's fish tape activator?
Electrician's fish tape activator?
(OP)
When using a conventional electrician's fish tape in a wall, I find that I frequently need to determine where the tape is located. I found non-contact hot circuit detectors are very useful, so I thought it might be feasible to make the fish tape "hot" by applying 120 V AC to it. But, in order to eliminate the possibility of serious shock, it would be driven by a high impedance--something like 120 Kilohms. That would limit the current in human contact to 1 mA, which apparently is quite safe.
Does such a commercial product exist? If not, is anyone interested in developing and marketing it? (Obviously, it needs to go through the UL approval process.) There should be a good market for such a device.
Does such a commercial product exist? If not, is anyone interested in developing and marketing it? (Obviously, it needs to go through the UL approval process.) There should be a good market for such a device.
Robert R. Wagner
ExpanTest, Inc.
http://home.gwi.net/expantest/






RE: Electrician's fish tape activator?
Try FiberTek Tracer tape: http://www.fibertekinc.com/pull_details.cfm?ID=5
RE: Electrician's fish tape activator?
I guess if you hook one end of 20 feet of wire to a hot then go check the unconnected end for being live this would show if those detectors are Magnetic or Electric field sensors.
RE: Electrician's fish tape activator?
The FiberTek product suggests using an RF signal: "Simply direct a radio signal on to the TRACERTAPE and follow conventional locating procedures." I'm not sure how many electricians have the means to do this right at hand. That's why I thought of the simpler application of a 60 Hz signal from a high-impedance source.
BTW: I noticed that GFI's are designed to trip at 5 mA, so applying 120 V through a 40 Kilohm resistor (3 mA), should be safe. In the commercial product, one could include a GFI, for an additional measure of safety.
Itsmoked:
No, the live circuit detector is electric field (though magfield detectors are available, too). See, for example, http://w
Thanks to both for your advice.
Doesn't anyone want to take up this idea and develop a product?
Robert R. Wagner
ExpanTest, Inc.
http://home.gwi.net/expantest/
RE: Electrician's fish tape activator?
I don't know if I like the energized tape idea. You can still kill someone many ways with 5mA..
Someones heart can go into some pathologic rythm from a tingle across the chest.
Not to mention the ol BZZZZZZYOW! While standing on a ladder or some other precarious position.
The low voltage signal tone would work just fine They use them to find pipes buried eight feet underground!