how do you use a clamp style ammeter

[tpolley]

i just bought a clamp style ammeter and i can't figure it out. the destructions say to clamp it over the hot wire but that seems alittle impossible as most all the electrical wires i deal with are molded together like the one in the picture. i can only get a reading of a few micro amps. what am i doing wrong?

 

[Stuart in MN]

It does have to go over the single wire you want to measure current in, it won't work putting it over a multiconductor cable. If you're trying to measure the power to a plug in device, you can make a short jumper cable with a plug on one end, a socket on the other, and individual wires in the middle. Then plug it into the wall, plug the device into it, and clamp your meter around the hot wire.

 

[W-Cummins]

Go to the big box store or to an electrical supplier and pickup a plug adapter made to test plug in devices. They are a molded adapter that allows you to clamp through them and isolates the hot wire as required for your meter. I think they are under $20.00

William....

 

[RPH]

You can also "wrap" the single conductor around the clamp for small amp loads. Just to remember to divide the reading by the number of wraps.

 

[Jim Stabe]

I had the same question. Is the intent to have the wire pass through the hole formed by the arms or to capture the wire between the ends of the pincers?

Jim

 

[mrb]

the wire has to go through the hole, with the pincers closed

 

[tpolley]

thanks for the info. i took an old extension cord and cut back the insulation to expose the individual wires and taped them up separately..

 

[Mattlt]

thanks for the info. i took an old extension cord and cut back the insulation to expose the individual wires and taped them up separately..

Drawing over 13 amps, I hope that is at least a 20-amp circuit?

 

[Mike83]

Drawing over 13 amps, I hope that is at least a 20-amp circuit?

At least 12ga wire you mean. Doesn't matter if breaker is 15 or 20, as long as it is the weakest link ie trips before you wires or outlets start on fire.

I have an old 30 amp breaker for my garage circuit. I need to fix that. Don't tell my insurance company

 

[tpolley]

Drawing over 13 amps, I hope that is at least a 20-amp circuit?

i assume it's a 20 amp circuit. the plug has the little sideways/vertical prong on the hot side. in the picture i'm measuring a little space heater like you'd buy from walmart
i've been measuring everything it sight just for the fun of it. 15 amps isn't very damn much. i'm supprised.

 

[Mattlt]

At least 12ga wire you mean. Doesn't matter if breaker is 15 or 20, as long as it is the weakest link ie trips before you wires or outlets start on fire.



Actually, I was referring to the 80% rule, but yes, you are correct - nothing wrong with a 15 amp breaker on #12 wire.

 

[2LTim]

i assume it's a 20 amp circuit. the plug has the little sideways/vertical prong on the hot side. in the picture i'm measuring a little space heater like you'd buy from walmart
i've been measuring everything it sight just for the fun of it. 15 amps isn't very damn much. i'm supprised.

Small poit of fact, the "Little sideways/vertical Prong" is the neutral side of the plug/recept. Or at least it better be!
Tim

 

[ddawg16]

It looks like you all have it figured out.....

But just for reference.....Left Hand Rule....

Take your left hand...grab the wire with your thumb pointing in the direction of current flow (going towards the load). The direction of your fingers is the direction the magnetic waves are going around the wire....'this' is what the clamp on probe is picking up.

When you clamp it around two wires (one wire going to the load, the other returning)...you should measure 0. Because one wire has current going to the load, the other comming back....the fields cancel out....

Add that to your "So What" file.....

 

[Dq383500]

Go to the big box store or to an electrical supplier and pickup a plug adapter made to test plug in devices. They are a molded adapter that allows you to clamp through them and isolates the hot wire as required for your meter. I think they are under $20.00

William....

So that is what that is! Every once in a while I pass over it in my junk drawer, (like for 5 years) Wow learned something new today, Now I can go to bed smarter ! Thanx

 

[MisterCMK]

Be careful using a clamp meter on circuits above 240v to ground if the meter is not rated for it.