My Water Main is Hot

[readydave8]

There is no such a forum of 'brilliant 'minds here........

An opportunity for you to start one.

 

[kwired]

Must be a great clamp, I often read a few amps clamped on nothing.

I just don't have much faith in clamps at those low currents.

When I am trying to measure a reading this low with a clamp meter I like to put 10 loops in the conductor being measured and then clamp around all 10 loops - the reading will be 10x the actual current.

 

[iwire]

When I am trying to measure a reading this low with a clamp meter I like to put 10 loops in the conductor being measured and then clamp around all 10 loops - the reading will be 10x the actual current.

Yes, been there as well, you can also buy plug in versions that do the same thing.

But my 87 can handle 15 to 20 amps through it so if I am going for low readings I just use that.

 

[kwired]

Yes, been there as well, you can also buy plug in versions that do the same thing.

But my 87 can handle 15 to 20 amps through it so if I am going for low readings I just use that.

I have a plug in adapter for 5-15 in - 5-15 out and places to clamp your meter - both 1x and 10x. Is very handy when you want to measure something cord and plug connected and don't want to take something apart to access the leads to make measurements. Even has two holes where you can poke voltmeter probes into to check voltage. (probably same thing you are talking about)

 

[iwire]

I have a plug in adapter for 5-15 in - 5-15 out and places to clamp your meter - both 1x and 10x. Is very handy when you want to measure something cord and plug connected and don't want to take something apart to access the leads to make measurements.

Dad had an old (likely 1960s) Amprobe version of that, I have not owned one.

I do have a Fluke cord that has a 5-15 in and out but it has leads to plug into a multimeter that run the load through the meter for current measurement.

 

[Besoeker]

Dad had an old (likely 1960s) Amprobe version of that, I have not owned one.

I do have a Fluke cord that has a 5-15 in and out but it has leads to plug into a multimeter that run the load through the meter for current measurement.

I use something similar. It is a Fluke clip on CT that has a 1000:1 ratio. It is designed to plug into a multimeter. But mostly I use it with a 10 ohm burden resistor and look across that with a scope. It's how I recorded some of the waveforms that I've submitted to this forum.

 

[PetrosA]

I got a line splitter from the AEMC site for dirt cheap:

http://store01.prostores.com/servlet/aemc/the-452/Line-Splitter-Model-ALS-dsh-1/Detail

I also got one of these:

http://store01.prostores.com/servlet/aemc/the-468/Outlet-Tester-Model-OT-dsh-2/Detail

and one of these:

http://store01.prostores.com/servlet/aemc/the-140/5000-dsh-Count-Digital-Multimeter-Model/Detail

and because the order was over $50, I got one of these for free

http://store01.prostores.com/servlet/aemc/the-206/AC-Current-Probe--dsh-/Detail

I keep the DMM for home use (It's a great, fast DMM, but I have three others and two clamps on the truck) and the accessories go to work with me.

 

[gar]

120129-1111 EST

My Fluke Y8100 DC/AC Current Probe has a 200 A and a 20 A range. Output is 2V for 200 or 20. The range is switch selected.

Before making AC measurements I balance it within 10 MV output on DC with no current.

On AC with a Fluke 27 as the readout meter in the AC millivolt range I read 1.6 mV when away from any significant magnetic fields. This means the probe has a 16 mA noise level without low pass filtering. I might point out that the Fluke 27 reads 0.0 mV with a short across the terminals. This is not true of a Fluke 87. My Beckman 4410 has an AC shorted input noise level of about 0.01 mV (10 microvolts). It also reads about 1.6 mV with the Fluke current probe.

If I switch to DC with the Fluke probe, then I can see the effects of the earth's magnetic field. This includes going from positive to negative with orientation.

In AC on the Fluke 27 the magnetic field from the current in my water pipe is insufficient to produce a reading above the noise level with nothing thru the probe hole. My water pipe is too large to clamp around it with the Fluke probe. But within the electrical panel the magnetic fields are great enough to exceed the noise level by a considerable amount, without directly closing around a wire.

Presently I have about 60 mA in the grounding wire to my water pipe, and I have no ground rod at the house.


On splitters --- my new Amprobe ELS2A works with modern 3 prong plugs including the wide blade on the neutral (common, low) side. This is 1x and 10x and I believe a maximum of 20 A continuous. Pulsed higher would be OK. My old Amprobe splitter would accept a 3 prong plug if the wide blade was not wide, but would provide no ground path.




iwire:

What does 5-15 in mean.
.

 

[kwired]

iwire:

What does 5-15 in mean.
.

NEMA 5-15 - the standard 120 volt receptacle

 

[gar]

120129-1523 EST

Thanks kwired.

.