How to measure phase amps? Can I use a clamp meter?

[Offroader]

I have access to this Fluke 367 clamp meter and was wondering if I could wrap it around my phase wires and if this will tell me about how many phase amps I am pulling?

Here is the meter. I just need a rough idea about how many amps are being sent over to the motor.

http://en-us.fluke.com/products/clamp-meters/fluke-376-clamp-meter.html#overview


Thanks,

 

[macribs]

AFAIK that is what a clamp meter does. So yes you should see the amps to the motor.

 

[Offroader]

Yeah it seems it should work, although somehow I barely remember reading something here a long time ago and there was some issues with doing this.

If this does work I can finally see what kind of phase amps the Max-E is drawing compared to the draw of the lyen 18fet.

Max-E limits the phase amps and I can feel a lot less power compared to the Lyen 18fet which supposedly with a block time set at 10 seconds, I am pulling unlimited phase amps. I am curious to see just how many more the lyen 18fet pulls. The Lyen 18fet also heats up the motor much faster and more compared to the max-e, when the max-e is pushing peak watts at 6000 vs lyen at 4000.

This tells me those phase amps I'm pulling with the Lyen 18fet must be a lot more compared to the Max-E.

 

[Punx0r]

I can think of two possible problems with using a clamp meter on the motor phase wires:

1) Waveform will not be sinusoidal. I believe most clamp meters only work accurately with DC or pure sine wave
2) Unless the motor is stalled the power in each phase wire will not be continuous/steady-state.

 

[Doctorbass]

If your clamp meter is true RMS it should not be a problem to measure non sinusoidal waveform.

The true RMS calculate all harmonic and all other ampliture that are not pure sinewave.

Doc

 

[Doctorbass]

The true RMS calculate all harmonic

Doc

In the range of 50/60Hz the cheap ones.

I need a number of frequency at full throttle, so to suggest the right one.

Fluke 337 :wink:

Doc