Fluke 1738 Power Quality Loggers

[W@ttson]

I wanted to see if anyone has used the Fluke 1738 before. I want to connect one to the output of a drive to measure mostly the power (kw) to the motor. In the setup of the meter you are supposed to select a topology distribution system. Attached are the diagrams that you can select from. Since I am connecting this to the output of a drive to measure the power delivered to the motor, I don't have a neutral, but I want to measure the voltage and current. My distribution system feeding the drive is a 4W wye system. However, to the motor there is only the 3 phases going to it. So I think the correct selection is the 3PH Delta Energy Study since it doesn't show a neutral and has voltage and current measurements.

Or should I still select 3 PH wye and just not connect anything to the non-existent neutral?

What do you all think?

 

[Cing37]

I would call your dealer for advice. I was in a similar situation a few months ago and we just disregarded the Neutral. Readings came out just fine. I would be interested to see what the rental/dealer for the meter has to say.

 

[ATSman]

I would choose the Delta connection since there would be no load current flowing in the neutral conductor anyway.
Try both connections and prove it to yourself.

 

[W@ttson]

I tried to contact the dealer but getting support from them is a bit of a drag.

I ended up doing the delta and results came out fine. I think the same would have resulted if using the wye and not connecting the neutral. I think what ends up being most affected by it are the harmonic measurements?

I didn't have time to test it both ways, if I come across the opportunity again in the future I will try.

 

[Cing37]

I tried to contact the dealer but getting support from them is a bit of a drag.

I ended up doing the delta and results came out fine. I think the same would have resulted if using the wye and not connecting the neutral. I think what ends up being most affected by it are the harmonic measurements?

I didn't have time to test it both ways, if I come across the opportunity again in the future I will try.

I had bogus harmonic readings when I took the delta readings. If I thought about it long enough I could probably figure out why, but I wasn't after harmonic readings so I didn't bother. Glad it worked out for ya.