# Measuring a drive's Hz output



## oodly (Sep 8, 2016)

I was given a UEI DL479 meter that seems like a good all purpose multimeter with lots of functions. It has a Hz function which reads 60 on house power but gets all crazy on the output of a drive, like 5.1 KHz. I know that the reason my Fluke 87 can read a VFD's output properly is because it has a low pass filter... is this UEI meter just incapable of taking that reading because it doesn't have that feature?


----------



## Rora (Jan 31, 2017)

Yep, needs a low-pass filter in order to properly read VFD output.


----------



## gpop (May 14, 2018)

oodly said:


> I was given a UEI DL479 meter that seems like a good all purpose multimeter with lots of functions. It has a Hz function which reads 60 on house power but gets all crazy on the output of a drive, like 5.1 KHz. I know that the reason my Fluke 87 can read a VFD's output properly is because it has a low pass filter... is this UEI meter just incapable of taking that reading because it doesn't have that feature?


The meter might actually be correct. If you read the vfd manual you will probably find that the gates are running at 6khz. On some vfds you can change the gate speed which will reduce motor noise (may increase vfd heat sink temp). 

Probably makes it a completely useless reading but its shows that the meter is doing something rather than just spitting out a random number for no reason.


----------



## joebanana (Dec 21, 2010)

Is your UEI meter true RMS?


----------



## Electrical-EE (May 4, 2017)

*UEI can deal upto 400 kHZ*

As far as I know this device can deal upto 400 kHz frequency


----------



## Electrical-EE (May 4, 2017)

joebanana said:


> Is your UEI meter true RMS?


DL479 is true rms multimeter


----------

