Clamp type DVOM - how to use

[OldnSlo]

So I am borrowing this type of DVOM, and silly me I thought you just clamp it on some Romex and you would get a reading of the voltage. I get goose eggs.

Using the test leads, I get voltage. I know the gauge works. Is the clamp on style supposed to read ONE wire (black or white) at a time?

 

[lametec]

The clamp is for reading amperage. Voltage still has to be measured with the test leads.

To use the clamp to read amps, clamp around ONE conductor. It works by measuring the magnetic field around the cable, and if you have both wires in the clamp, the magnetic fields from the two wires cancel each other out.

 

[OldnSlo]

Simple enough...my bad on how I thought I would use it.

So, the intended purpose was to ensure I have picked the correct run of romex in the attic for a given circuit (mid run). I can ***** the insulation with test leads, but did not want to do that.

Anyone have a slick method?

 

[KenB]

Don't damage the insulation. Get a non-contact meter, like this: http://www.amazon.com/dp/B000EJ332O/?tag=atomicindus08-20

Ken

 

[OldnSlo]

Thanks Ken, I've seen those before....and had forgotten them.

Sounds like case closed! Thanks all!

 

[MrMark]

Simple enough...my bad on how I thought I would use it.

So, the intended purpose was to ensure I have picked the correct run of romex in the attic for a given circuit (mid run). I can ***** the insulation with test leads, but did not want to do that.

Anyone have a slick method?

If your goal is to measure the current through the wire the best way to do it with the romex is to clamp the wire at the panel by going around the wire where it connects to the breaker. That will get the current for the whole circuit, so be aware of that.

 

[unslow1]

Don't damage the insulation. Get a non-contact meter, like this: http://www.amazon.com/dp/B000EJ332O/?tag=atomicindus08-20

Ken

You can pick those up cheap. Harbor Freight, Lowe's, Menard's, Sears or just about any hardware store. If you do much electrical you want at least one. Great for those lights where someone interrupted the ground not the positive with the switch.

 

[Alchymist]

If you are just circuit locating, borrow one of the tone generating "circuit breaker finder"s.
Plug in the generator at circuit end, and you should be able to detect the tone in the cable itself mid run.

 

[OldnSlo]

If you are just circuit locating, borrow one of the tone generating "circuit breaker finder"s.

Saw that at HF....seemed it was for Coax, cable, phone, 'puters....nowhere did it say 110v.

Regardless, life is back under control. Got 'er done!

Thanks!

 

[Alchymist]

Saw that at HF....seemed it was for Coax, cable, phone, 'puters....nowhere did it say 110v.

Regardless, life is back under control. Got 'er done!

Thanks!

Look for something like this:

http://www.tequipment.net/SperryCS61200.html

 

[Milton Shaw]

They are also handy for checking to see if someone hooked up dryer/stove wrong and have hooked the hot wire to the ground. Saw a dryer welded to a washer that had been done that way. Rubbed the paint off and welded itself to the washer and then burned out the ground on the washer, so both washer and dryer had 120 volts on all metal parts. Working on appliances, I carried one all the time and check most appliances before I touched them, found a lot of hot appliances from wiring in the house/appliance bad. Just takes one shock across the heart and you may be gone.