Tried a cheap toner probe on a 20 year old panel and got nothing but static

Tried a cheap toner probe on a 20 year old panel and got nothing but static. Last week I was tracing a circuit in an old strip mall over in Bakersfield and figured I'd save some time with a $40 toner probe kit off Amazon instead of my usual Fluke. Hooked it up to a live breaker and all I got was this weak buzzing sound that faded in and out... couldn't hear anything clear past 10 feet. Tried grounding it different ways, checked the batteries twice, even swapped the alligator clips. After about 45 minutes of fighting it I gave up and pulled out my old tracer that I've had for years and it worked perfect first try. Learned that cheap test gear just isn't worth it when you're on the clock and dealing with older wiring that's got noise from fluorescents and ballasts. Anybody else had luck with those budget toner kits or is it just me?

3 comments

3 Comments

the_amy10d ago

Wait, were you running it on a live breaker? Most of those cheap toner probes are designed for dead circuits only. You're lucky you didn't pop the probe or worse, get a surprise. Older panels with all that fluorescent noise are tough enough without sending a signal through a live line.

eric_knight710d ago

Oh man, "live breaker" exactly. I did the same stupid thing with one of those $30 Klein toners a few years back. Hooked it up to what I thought was a dead circuit in an old office building, but someone had tied a neutral from a different panel into that junction box. Probe started smoking within like 15 seconds, and I got a little tingle through the alligator clip. Threw that thing right in the trash and bought a Fluke. Those cheap probes just can't handle any live voltage at all, especially with all the ballast noise from old fluorescent fixtures.

lindal139d ago

I read somewhere that those cheap toner probes basically just send a weak signal and rely on the cable being clean and quiet. On older wiring in a strip mall with all that ballast noise, that weak signal just gets drowned out immediately. I heard a guy on another forum say you need something with variable gain or adjustable output to cut through interference in commercial buildings. Those $40 kits are fine for tracing a single cat5 cable in a quiet house but they just don't have the guts for real world noise. Learned that one the hard way myself.