Gardner Bender GVD-3505 Circuit Alert Non-Contact Voltage Tester with Pocket Clip

It does what I want it to.

THIS is what I call my "Electric Pencil". It is not a pencil of course. But when you want to check for live voltage in an electrical circuit (120/240 volts AC), THIS is the tester to get. Now there are many testers that do this function. And I have to believe that they are probably very good. But, what makes THIS tester stand out from the rest is the little wheel that you turn it on and off with. It is also a sensitivity control, and that makes all the difference. What you want to do is to identify a single wire if at all possible in an electrical circuit that has live voltage on it. With this tester, and careful adjustment of the sensitivity wheel, you can do that. You adjust the wheel as close to the minus sign (-) so you barely hear the beeping and LED flashing when just about touching a known live wire. When you move back just a very little bit, it should all stop. So when you do come close to a bundle of wires, and place the tip close to each individual wire (you do have to separate the wires obviously), only the live one(s) will sound and flash on the tester. This truly makes all the difference. I wouldn't be without one of these testers if I was working with wires that might be live. Safety first, or you won't need one, because you didn't make absolutely sure that THAT wire wasn't live. This tester can and will save your life if you use it correctly. At the price so low, how can you not get one?

Works for checking live wire without a meter

As a seasoned electrical engineer I have had many devices to detect and measure voltages. I still do a lot of hands-on electrical work.This Gardner Bender GVD-3505 is by far the simplest and highly sensitive detector. I have several other name brands but I bought a second GVD as a spare, because the others were disappointing. (And quite more expensive.)This unit is the best value/performance . The only downer is the LR44 button batteries.If they could only get AAA batteries into this unit then it would be near perfect!

I read reviews re early failure, and lower sensitivity, so I got FOUR of them.The first one I tested showed LED light and Beep noise for about 10 minutes, then the LED went dead. It still beeped properly. (It’s case is glued together, so no simple way to inspect it.)I returned that defective one.I Kept the other 3 and ran a more comprehensive test:(Corrected below: new testers are GVD-3505 (not -3503). My Old one was GVD-505A)I setup a TEST with an outdoor extension cord “AWG 14/2 w ground“ away from other wiring, stretched in air between a couple saw horses about 6 ft apart. Open circuit voltage at end of that cord was 126V AC 60Hz. (nothing plugged into cord end. It should be able to detect the voltage/60Hz, and not have to have current flowing through the wire. For example: It needs to be able to locate a burned out or loose wire nut where the voltage in that line “ends”.)I tested each of the new ones, and my years old GVD-505A on the initial power-on knob gain position, and then again at the maximum gain setting.My old GVD-505A tester: Beeped/lighted slowly at first gain sensitivity knob position when touched directly to the power cord.The four new GVD-3505 testers did not beep/light at that gain position at all.I had to turn the gain up two “groove/notches” in the control knobs before I could get them to respond while touching the electrical cord. The 4th one beeped/lighted a little bit faster at the 2nd notch position than the other 3.(And again, one of the 4 new ones at that point would not light up at all, though it beeped.)I then tested all 5 again: (4 new and my old one) at the maximum gain sensitivity setting: (using a non-metallic tape to measure side-distance at right angles to the power cord.).My OLD tester started beeping/lighting at 18 inches distance from the cord.Three of the new ones started beeping at 10 inches away from cord.ONE of the new ones was a bit more sensitive and started beeping/lighting at 14 inches distance.So it appears most of the new ones have a sensitivity of ~55% of that the old model had.— Except the one that failed right away, the other 3 are still working, and for simple non-metal conduit in 4” thick plaster board walls, it is sufficient to trace bad wire in a wall. Ceiling might be more difficult since there is no guarantee the wire is laying near, on, or between the deeper joists.Having noted that, I’ve still not found most of the other “AC Voltage Detectors” sold that even come close. They do not have variable sensitivity.In comparison, I got a Southwire 40150N tester, and it was unable to consistently detect voltage (when present) even when touching the bare wire. Sometimes it would work, but turn it off and on again, and sometimes it would not detect anything at all (at the same wire)— so It could be unsafe for me to trust it. It had no gain adjustment. Simply the on/off button. (I’ve had better results with a stud detector that has an AC wiring indicator light.)NOTE: There are better Wire tracers on Amazon, and they generate their own signal, and are much more sensitive. Some can be used on a live wire (but has to be connected to the wire). Some have to have AC power disconnected to the electrical wire, then it’s connected to that wire.With those, I was able to mark the path of shallower sewer line (via metal fish-tape), and also some underground rain gutter drain pipes. I haven’t used that one yet for tracing the path of a wire in a house just yet.