# Gv3000



## twgreen (Feb 25, 2009)

Recently I have been trouble shooting a GV3000 SE VFD and tried to get a frequency reading on the output side of the drive. Whenever I entered the panel my meter (Fluke 87v) would go crazy and not read frequency correctly or voltage. It would however work on test voltages so I eliminated the meter. Has anyone seen this before and if it is common then how would I go about getting these measurements? The drive is a 15Hp, 3Ph, 480v if it matters. Thanks for the info. 
We have since replaced the drive, motor, and gearbox, but I have not been able to retest to see it I can get these measurements.


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## InControl (Mar 20, 2007)

Your multimeter is not going to be able to read the PWM (Pulse-width modulation) of a VFD. 

Most VFD's have a keypad with a digital readout, that's where you will be able to see the frequency. Look through the manual and find the display parameters ( V, I, Hz, etc.).


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## twgreen (Feb 25, 2009)

Thank you for the info, I did not realize that I wouldn't be able to get a accurate reading. We have a operator interface module as well as the readout on the drive and both were tell me something different. As it turns out the readout on the drive display was correct. But it is nice to know the info on using my meter.


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## cdnelectrician (Mar 14, 2008)

The Fluke 87-5 has a filter on it allowing it to measure drive output voltage and frequency accurately does it not? It should be able to take a reading, unless you have it on the wrong setting.


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## cdnelectrician (Mar 14, 2008)

http://ca.fluke.com/caen/products/features.htm?cs_id=34473(FlukeProducts)&category=HMA(FlukeProducts)


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## InControl (Mar 20, 2007)

cdnelectrician said:


> The Fluke 87-5 has a filter on it allowing it to measure drive output voltage and frequency accurately does it not? It should be able to take a reading, unless you have it on the wrong setting.


Would you trust this reading on a Fluke meter?



twgreen said:


> As it turns out the readout on the drive display was correct. But it is nice to know the info on using my meter.


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## 5volts (Jan 11, 2008)

The Fluke 1587 as well has the low pass filter where you can accurately measure the PWM output from a VFD and see if the actual voltage matches the VFD output voltage on the _HIM_. It reads the exact hz on the output as well. And it has a built in insulation tester as well a "megger". I'm not to crazy about digital insulation testers though just a personal preference. 


This is a really nice demo shows how the meter works.

http://www.fluke.nl/comx/products/demos/1587_1577_en.swf




> Would you trust this reading on a Fluke meter?


 
I think so. More and more meters have the "special feature" low pass filter, I don't have one yet but I usually just check it with a digital and make sure the output voltage is balanced coming off the drive. If I did have one I would check it out and see if it reads and matches the VFD HIM accurately then it would end up in my toolbox. We are lucky though we have so many drives side by side. The easiest way to troubleshoot them sometimes is just to swing the the T leads to another drive and then we can eliminate the possibility of the drive not pusling correctly.


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