Need multimeter: Do inexpensive ones allow testing through insulated wire?

I've noticed here and there that the people servicing my A/C and
Heating system as well as the power company guys all seem to show up
with this wizbang multi-meter that has an attachment that can just
collar an insulated wire and read it.
I honestly don't remember if they were testing nominal voltage, or
current flow, or if one or the other is impossible.
Are such things available inexpensively? There are many times when
working with house (and car!) wiring that I really would bennefit from
reading the characteristics of a line without breaking into it.
Thanks!
Reply to
Thomas G. Marshall
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These 'clamp meters' are available in all price ranges. they only measure current using the clamp, the less expensive ones only measure A.C. current.
Reply to
Jasen Betts
Clamp-on AC ammeters (for household power) are available for under $50US. Clamp-on DC ammeters (for the car) are typically much more expensive. Active technology (chips) are required for the clamp-on DC ammeter, but only a passive current transformer required for the clamp-on AC ammeter.
John
Reply to
news
ac or dc voltage with contact points
Reply to
jonwheeler1
In article , "Thomas G. Marshall" wrote:
It sounds to me that you are likely to be in over your head. What are you trying to do? What do you mean b "read"? Do you want to read the imprint on the wire? :-) Other posters' guessed gthat you were describing a current measurement. Even if you got what you wanted, I would be concerned about your safety.
Bill
Reply to
Salmon Egg
I am not in over my head.
Reply to
Thomas G. Marshall
...[snip]...
Ah Thanks....the term is "clamp-on". I was told that such things were not available (by my local Ace Hardware store guy), hence the post here.
Is nominal voltage measurable in such a way?
Reply to
Thomas G. Marshall
Ah....gotcha.
Reply to
Thomas G. Marshall
Ignore prior question regarding voltage....asked and answered else- thread. THANKS!
Reply to
Thomas G. Marshall
...[snip]...
Sure; I was assuming that they were also "standard" multimeters.
Is there a brand people suggest for the low-end range? Here're an example of what I've done before (not in order).
1. General electrical installation within a house. 2. Inside a car, often rewiring something or other. 3. Repairing PC's, often trying to determine the degree a power supply is croaked. 4. Other DC wiring. 5. Testing impedance on A/C motors. (etc.)
So pretty much the home/hobbyist quality will work. I don't absurd impedance resolution, nor anything particularly special. I just want something competent.
Reply to
Thomas G. Marshall
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It's a $9.99 clamp on ampmeter/dvm
You CANNOT read (all) "the characteristics of a line" without breaking into it. You CAN measure the current in the line without breaking into it, and the meter in question works only on AC current that way. For other measurements that this meter can perform, you need to use the probes to contact uninsulated ends of the line. And this meter does not measure everything you might want to know. But if you want a cheap AC clamp meter, it is probably worth the cost.
Ed
Reply to
ehsjr
Oddly enough, many hardware stores carry them ... including Ace! (Hands up, anybody who's surprised.)
Many also include banana jacks that are used with standard test leads for measuring voltage; frequently just AC voltage, although some will do DC as well as basic resistance measurements.
The ones in hardware stores are usually Greenlee or Gardner Bender branded and feature large jaw openings and high ranges, appropriate for checking mains cables. They are also found with smaller openings and lower ranges for appropriately smaller jobs.
Better-than-hardware-store varieties can be found at places like
There are also add-on probes that terminate in banana plugs, intended to be used with regular multimeters.
Reply to
Rich Webb
For work with mains wiring in a house an AC non-contact voltage detection probe is essential:
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(FlukeProducts)You can get them on Ebay.
Any general purpose Multimeter will do the job you want. Fluke is best, but fairly expensive. Cheaper but brand name ones like Extech or Meterman/Amprobe are also good. Cheap no-name Ebay ones also work, but you get what you pay for quality-wise. You should not have to spend more than $50-$100.
Dave.
Reply to
David L. Jones
I commend you for asking the question on this group. And I do not want to lecture you...BUT if I knew anyone was to carry out any domestic electrical installation work and didn't know what a clamp-on (aka tong) ammeter was, i would be asking some serious questions as to their suitability for undertaking such work. May I suggest (at the very least) that you read a basic primer on electrical installation work before any more 'installations' to protect yourself and others associated with the installation. You do not mention where you are live but I presume from your ISP that it's stateside...and i am not familiar with the regulations over there. I know in Australia where I live now only licensed electricians can work on installations. Even home owners cannot work on their own domestic electrical installation. In the UK where i come from it is a bit easier and the law allows anyone 'appropriately ' qualified to work on an installation...but what is the definition of appropriate?...it's a little grey. The law may have changed since I left in 1994 anyway. Please do not consider this a 'dressing down' as it were..it's certainly not intended as such...just a plea for you to continue in your education via some appropriate training along the lines of, at the very least, a comprehensive, authoratitive training manual of some kind...there are lots to choos from. Please remember electricity can kill! Leaky taps cannot! Regards Daniel
Reply to
nidan.danny
Ï "David L. Jones" Ýãñáøå óôï ìÞíõìá news:tTxxl.3089$ snipped-for-privacy@newsfe10.iad...
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(FlukeProducts)I have something similar, a detector bought from Lidl, that can detect wood, steel and AC voltage, just by sliding it near the suspect area. It's very nice
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,
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) Lidl is a supermarket, that brings along goodies like that, beyond the usual grocery.
Reply to
Tzortzakakis Dimitrios
...[snip]...
I know what an ammeter is...I've used the ammeter/voltmeter/ohmmeter within multimeters off and on for years. I didn't know that the term was "clamp on".
You've made an assumptive leap in logic here...there was nothing in my statement that suggested that I did not do proper research before any electrical installations. Nor is there anything that suggests that I'm not doing such research now.
Check your assumptions please. If what you wanted to ask was "are you comfortable doing such installations?" then ask. Don't go launching off with language sounding like an admonishment and then claim it isn't meant to be a dressing down. Particularly when you ran to ill- supported conclusions.
Posts like that are what damage usenet and make it less likely that others will ask questions. There's always someone's pedantic statement to wade through.
Reply to
Thomas G. Marshall
OK! Lots of good tips here. Thanks all!
Reply to
Thomas G. Marshall
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(FlukeProducts)> I have something similar, a detector bought from Lidl, that can detect
Yes, these "Stud Finders" all have AC voltage detection now too. But not as useful or precise (the range is very large) as the proper tool for the job.
Dave.
Reply to
David L. Jones
To please a couple of the more pedantic characters in this thread, in the interest of full disclosure I thought I'd explain how it is I am hardly inexperienced.
I am installing a light fixture. When I took the old light fixture off I noticed in the ceiling that there was a black wire that came in and was tied to another black wire that continued the run. From my DC days I know the black wire to be ground, so I spliced into it and attached the light's green wire.
I think the fixture is faulty because when I connected it's white wire to the white wire in the ceiling I felt a little funny. But my circuit breaker is also faulty because it threw right away. Downstairs I couldn't get the breaker to stay in one position, it was that worn, so I put a self-tapping screw direction through the top of the switch to hold in the on position.
Light works! But buzzes & flickers horribly. Lots of noise in the breaker box too. I'm blaming the switch upstairs....it's the only thing left. I know that it isn't a 3 way switch because it only goes two positions, so I'm not quite sure what is going on here. I can't even guess what the red wire up there is for.
There's always some wire left behind in all my installations....you know how it is.
Reply to
Thomas G. Marshall
Green is safety ground & black is hot, not ground. The green is never to be used to connect anything other than the frame of the fixtures, outlets or switches.
White is neutral, black is hot, green is safety ground. Your conections are in violation of the electrical code, and could kill someone.
The two black wires connected in the box allowed the AC line to continue to the switch, and return on another wire, which is likely white, but should be marked red or any color other than green or white.
Its no wonder your breaker is tripping.
Reply to
Michael A. Terrell

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