Non-contact voltage detectors

Hey fellas,

A while back there was a discussion about meters and such that included some talk about non-contact voltage detectors. I can't find it, so I'm posting a new thread.

With the growing concern over arc flash, we're looking at buying some for the techs as a supplement to their Fluke DVMs and Greenlee clamp-ons. Something like the Fluke VoltAlert™ 1AC Voltage Detector. Do any of you use these things? What make/model? Any feedback you have would be very much apreciated. Thanks in advance.

I sometimes use them for quick troubleshooting, but NEVER for safety reasons (making sure a power source is disconnected).

If I'm going to get my fingers anywhere near a potentially live wire or piece of metal, I'll use an actual meter, and check it first on a known live circuit.

Personal opinion

I do not care for them but many many people use them now. The only thing I can see they would be good for is to verify power is possibly present, never to determine if ckt is off. In my experience I have not found them reliable to properly verify power off conditions.

I personally do not trust them and believes it allows people to develop another bad habit. This is another "shortcut" being promoted in an area that should not use shortcuts.

These fall into the same category as using pliers when box end wrenches should be used. I could recite more examples but everyone will decide on their own.

Check this out, they do recommend to "re-Verify" on a known voltage source.
http://www.graceport.com/ChekVolt/Ds-ChekVolt.shtml

I used these a lot when I was trouble shooting heat tape traces. After using it for a while I thought it was very trustworthy.

I also used the Volt Alert from Fluke extensively, it is a useful tool to perform a quick recheck of a presumably "dead" or de-energized panel or to quick check for foriegn voltage. I would select a model that "rings". Keep in mind that these units only detect AC above 90 volts. They should be used as a supplement, not a replacement for your standard DMM.

William Martin said:

I also used the Volt Alert from Fluke extensively, it is a useful tool to perform a quick recheck of a presumably "dead" or de-energized panel or to quick check for foriegn voltage. I would select a model that "rings". Keep in mind that these units only detect AC above 90 volts. They should be used as a supplement, not a replacement for your standard DMM.

Click to expand...

We use the Fluke Volt Alert. Our rule is that if it indicates power is present then assume it is. If it does not indicate power present then dig out your multi meter and make sure before you trust it.

rsdoran said:

I do not care for them but many many people use them now. The only thing I can see they would be good for is to verify power is possibly present, never to determine if ckt is off. In my experience I have not found them reliable to properly verify power off conditions.

I personally do not trust them and believes it allows people to develop another bad habit. This is another "shortcut" being promoted in an area that should not use shortcuts.

These fall into the same category as using pliers when box end wrenches should be used. I could recite more examples but everyone will decide on their own.

Click to expand...

Dead on Ron...

We use the Fluke Volt Alert. Our rule is that if it indicates power is present then assume it is. If it does not indicate power present then dig out your multi meter and make sure before you trust it.

Click to expand...

Then why even use them if you still have to use a regular DVOM to verify? Isn't that adding an extra step and unnecessary time?

The only time I have found them useful was for finding the end of a wire that was buried in a raceway with about a hundred other wires. We applied power to the wire we were trying to trace and made sure all the other power was off, then went to the end of the raceway and used the voltage detector to quickly locate the one wire we wanted.

The thing that interests me most in this thread is that people seem to think that a DMM is the right tool for this job. I am not convinced about the reliability of the non contact detectors however the Health and Safety people normally insist that a DMM is not acceptable when proving a circuit dead. A purpose made potential indicator should be used for this. The issue here is that there are a large number of possible failure modes for a DMM which could result in a 0V reading when a voltage is actually present. Whichever instrument is used you should always prove the tester before and after the test before working on the circuit. This is second nature to anyone working on HV systems but is commonly skipped on LV systems.
Andybr

I have used them, but when it really matters, I test with something I trust.

I trust my Wiggy (solenoid voltmeter/tester for you newbies).

I trust my screwdriver, across tterminals to make sure something is dead (old screwdrivers don't always work for this, make sure you use one that is new AND expen$ive!).

I sometimes trust tapping two wires together (not recommended for 480), but have had the wires draw a nice arc, sometimes get stuck together, and NOT trip a breaker.

I generally trust my neon screwdriver volt tester, but have gotton some false readings from it. I often get false hots, but on occaision get a false dead.

I always trust common sense. You are only as safe as you want to be!

I can not tell you why but over the years I developed the habit of testing my meter everytime I use it i,e, get a live reading first. In my situation, which is troubleshooting/servicing, just knowing its live or not is not enough, I want/need to know the values that are present in most situations. In an attempt to be sure my Fluke 87 is accurate I try to have it factory calibrated every year or so.

People are creatures of habit and I have seen electricians (and others) that got into the habit of using "tics" to determine a ckt was "dead" then short something because it was not.

I saw an HVAC tech working on Honeywell burner controls on a gravure press burn up about $3,000 worth of controls because he used a "tic" and the control voltage was 24vac. He may not be a good example, in another incident he applied 120vac to the ckt and burned up the controller.

All I can say is I have seen some bad habits develop from their use.

I got something similar to the Fluke VoltAlert™ 1AC that also indicates magnetic fields.

http://www.radionics.ie/cgi-bin/bv/rswww/searchBrowseAction.do?D=voltage%20noncontact&Nr=AND%28avl%3aie%2csearchDiscon_ie%3aN%29&Ntk=I18NAll&Nty=1&Ntt=voltage%20noncontact&Dx=mode%20matchpartial&Ntx=mode%20matchpartial&N=0&name=SiteStandard&forwardingPage=line&R=0254099&callingPage=/jsp/search/search.jsp&BV_SessionID=@@@@0332193032.1172259120@@@@&BV_EngineID=ccckaddkfdjfihicefeceeldgkidhgi.0&cacheID=ienetscape

The magnetic function is the most useful as it can quickly tell me if a valve is energised (otherwise I would need to check both the supply voltage and check the coil for resistance)

The non-contact voltage function is perfect for finding blown/loose bulbs on Christmas lights but I'd use a DMM for "real" work

OK Ron, I'll bite. What's a "tic"?

keithkyll said:

OK Ron, I'll bite. What's a "tic"?

Click to expand...

http://www.contractor-books.com/AM/AM-High-V_Testers.htm

Not trying to sound like a smart A$$ but what does a lineman use to check for power when he is up a pole? A DMM?