I am in the process of installing a shitload of T8's in my parents'
kitche. BUT, there was a severe electrical storm today, and I'm
paranoid about lightning. So I just walked around Lowes in the
electrical section looking at all the goofy plugs.
I looked at the wire strippers and other assorted tools and came
Gardner Bender Circuit Alert Non-Contact Voltage Detector
Apparently one waves it around an electrica cable to detect the
presence of AC power.
Sounds pretty nifty.
Do these actually work? Wouldnt there have to be a "flow" of power,
and therefore a load on the line for it todetect anything? Or can one
simply have nothing on the line and just an open LIVE circuit?
I use a different brand. Quite useful. You can determine if a wire is a
hot when the color might not indicate - like knob & tube.
They work by detecting the electric field.
The gimmics that identify the circuit breaker for an outlet put a
current signal on the circuit at the outlet and detect the signal in the
magnetic field at the breaker.
As James said, test it before before you trust it.
trusting my life to something I get from wal-mart... Has me a bit uneasy.
When I opened up the fixtures I was going to replace, a little voice told me
to get one of thse magic wands.
The breaker was turned off... but still.
I don't know why.
I'm not too wild about these for voltage checks, although they are the
cat's pyjamas for finding where a cable run is behind the drywall (saved
myself from nailing through in the wrong spot more than once now). If
you are at risk from getting zapped by leads in a conn box somewhere,
better by far IMHO to check with a multimeter. You can get one at
Canadian Tire or Home Depot or wherever at a pretty reasonable price,
and they're pretty good quality and precision, unless you're an
electronics enthusiast looking for four decimal places.
While personally I prefer analogue meters, they do have some potential
problems such as low input impedance (meaning they can "load" a circuit
down), and it's too easy to get erroneous readings or damage the meter
if you forget to select the correct range. Most digitals are either
auto-ranging or will give you a warning if your input exceeds the range
One thing I would stress is whether you go for analogue or digital,
check that it's rated at least Category II. This relates to what kind of
transients it can handle. Category I is the lowest; and is considered
suitable for electronics and telecommunications equipment. Category II
is for branch circuits - lighting, appliances, 120/240 volt distribution
inside a building. Category III is for distribution circuits, feeder
panels, etc.; basically anything up to the utility transformer. Category
IV is the highest level. Obviously the higher category rating you get,
the more expensive the meter will be, all else being equal.
"Take sides! Always take sides! You may sometimes be wrong - but the man
who refuses to take sides must *always* be wrong! Heaven save us from
On Jul 30, 11:21 pm, email@example.com (Edward) wrote:
Yes these things do work and work well. It saved me a few times. The
one I have is made by Fluke and would recommend it.
What they do is detect the Electrical field around a wire and beep
when there is one. Note that they do not work by detecting a magnetic
field that Mark (another poster) mentioned. When no current flows
there is no magnetic field. I.E. if you have a hot wire dangling
around in the air, it will have not magnetic field because there is no
current, but it will have a Electical Potential field, and it is this
that the Voltage tester picks up.
The nice thing is, unlike a multimeter which you need to make pysical
contact to a piece of metal, you can check if a lead is hot or not
without having to strip it or to get at a metal contact. This is nice
in that you are always insulated from electrical power. Checking with
a multimeter is also a good test. I do both, first with the VoltAlert,
then with the multimeter.
On Jul 30, 10:21 pm, firstname.lastname@example.org (Edward) wrote:
The Gardner I have churps when you 1st press the clip...to tell you if
the battery is OK.
It can't identify a blown 220V cartridge fuse.
It can't be detecting magnetism...there isn't necessarily a flow of
current for it to ID a hot wire.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.