ECN Forum Forums General Topics of the Trade General Discussion Area Residual Voltage

I think it is a matter of personal choice of equipment, as for as the DMM, Solenoid debate goes. Both have benifits, and draw backs.

A lot of things I cant do with a wiggy, but dont reffer to a potential seen on a meter as "Phantom or Ghost", IMO belief in such things in that context can only lead to trouble. It may not be usable under even the smallest load, but it is there. Likewise, just because a solinoid is popped up in a certain range, there is a big difference in 120 vs. 150v or 90v that is not totally obvious on a Wiggy. Both instruments are subject to interpitation to some degree. But whatever the choice in tool is, you need to know the limitations of it. I have a Fluke 322 that I use for most things, it does the job, and I like the way it does it. Not to look cool.

On the original question, "One, is that the voltage is being induced on the wire. The other is that at least two circuits are sharing a neutral and the voltage is being back-fed. What do you think???"

Could be either, depending on the circuit and layout of it, and what it is measured against.

"I still get about 15 Volts coming through to the outlet in the ceiling when changing a light or ceiling fan. When the circuit breaker is turned off, the voltage drops to zero."

15volts is obviously not a usable voltage for the intended circuit, but does not mean it is not there. Think about the circuit path, where you are measuring you could be about 100' from the panel. Wind all that wire into some neat coils and you could end up with more, and it could be usable to boot.

I have to agree with the mods on this one, wiggy type testers for basic resi branch circuits & DMMs for in-depth troubleshooting......like on a PLC where a wiggy can actually turn stuff on ! (which is handy sometimes)

or a DC drive where the SCRs don't hold up to the "kick" from a wiggy

OK guys, I see I'm not convincing anyone here so please humor me. If a Wiggy type solenoid tester is your final arbitor of the safety of delving into a box or panel, PLEASE trust but verify. Firmly grasp the neutral or ground but give those "tested dead" hots the back of your hand first. Half the time, it's the surprise of the tingle that causes the most damage. And when the impedance of the tester is so much lower than the impedance of the user, these things shall happen. I'd rather be accused of beating a dead horse than hear of a dead electrician.
Joe

My, my, my....it seems that I've opened a can of worms here!

Just like Tim "the tool man" Taylor, I can never have too many tools -- or boy toys, as my wife calls them.

I can see a benefit to each of them, so I'll keep both on the truck. I don't recall the model number of my Fluke, but it is a clamp-on ammeter. I do use it quite often to check for proper line voltages as well as current draw for motors, etc. At the same time, I like to test open branch circuits to ensure that they are off before I connect a light fixture or other device. So, a wiggy would come in handy for these "on/off" tests (which is what I had been using my volt-tic for, but apparently it isn't too trustworthy).

As far as what looks "cool" is concerned, the average person is just as impressed with my volt-tic as they are my DMM. Others are more love-struck by my drills than any specific electrical tools. I think a Wiggy looks pretty cool too. Kind of retro, but cool.

Thanks again for the abundance of information.

Kevin

Kevin, just so you don't feel bad- I might have related this story awhile back.

My shop is next to a utility room. I go into the utility room and flip the wall switch and the one fluorescent fixture doesn't light. Simple problem, should be able to take care of it with my eyes closed.

I change the tubes then I check the breaker- no dice. I take the reflector off the fixture and disconnect the feed to see if there is voltage present.

Now, since I'm basically a lazy fellow and my Fluke was sitting a few steps away on the bench and my Wiggy was out in the truck guess what I used? Yup and it measured 120 volts.

Ahaa, bad ballast! I replace it. STILL doesn't work. So after spending time and money finally my brain kicks in. I check the voltage again this time with my Wiggy. Zilch.

I check the switch and find that it wasn't closing, pitted contacts that presented a high resistance. High enough in series with the Fluke's high impedance to still show 120 volts. Put a load on it and it goes to zero.

Just goes to show ya. The right tool will save you time and money.

-Hal