I’m not much of a tool person, but have my collection of tools and occasionally pick up something that looks like it could be useful. After one of my last projects doing electrical work, I picked up a Klein Non-Contact Voltage Tester from Home Depot. The concept is pretty simple, turn it on, wave it near a wire, electrical outlet, light switch, etc. and it will beep if there is electricity flowing. I’ve used it a few times mainly just to see how cool it is.
This past weekend, I discovered that the motion sensor in an outside light wasn’t working, so I needed to fix it. The problem was that since it wasn’t working, I didn’t know which circuit breaker to turn off and just relying on the light switch was potentially dangerous. While the switch was in a box with 2 other switches, I could hope that they were all on the same circuit, but given my luck, someone probably went against code and wired it such that 2 circuit breakers controlled the box.
I remembered that I had the Klein tool and pulled it out. With the breaker on, waving the tool over the switch showed electricity flowing. While I went outside to the breaker box, my wife, used the tool and let me know when I hit the right breaker. I was pretty confident that I wasn’t going to get shocked, so I took the light off the wall, used the tool again and verified that I wasn’t going to get zapped.
This tool is absolutely a tool that should be in every handyman’s (or handywoman’s) toolbox. It’s relatively inexpensive and saves you the trouble of getting knocked on your rear when you touch the live wires.
Pros
- Relatively inexpensive.
- Uses standard batteries.
- Easy to use.
Cons
- After changing the batteries the button gets stuck a lot requiring some wiggling to get it to work.
Summary
I definitely recommend this product. I’m sure I can resolve the hiccup with the switch by rubbing a little bar soap on the places that the button rubs. I wish I had gotten this years ago as I’ve gotten zapped at least twice because I wasn’t careful enough; I do test every outlet, but made assumptions because outlets in the same room were out, but not the ones that zapped me. This tool would have immediately told me to stop; it’s easier to use than a standard 3 prong tester or a regular test meter.
There is no problem running two circuits to the same junction box provided there is enough space in the box and you do not combine neutrals from one circuit with neutrals from the other circuit.
That said, I use my non-contact voltage sensor all the time. A great tool.
I couldn’t find a code reference for this, but have always taken my father’s word on it as he has done construction inspection his entire career. While it may be permitted, it sure is dangerous unless the breakers are jumpered so that both turn off at the same time. I’d hate to turn off one breaker, put my hands in the box and find out the hard way that another breaker isn’t off!