Mophorn VFD drives

Karl_T

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Anyone used a Mophorn VFD drive?

They are on Amazon for a fraction of other vendor's pricing

I am after a 10 horse unit for my air compressor. sound to good to be true
 
Well that's about $500 less than I paid for mine. Not sure what that means, maybe I over paid. :) Never heard of them before.
 
Never heard of this brand, looks like a generic of the HY, like other ones that all look the same Lapond, Vevor, etc.. I am not a big fan of HY (Huanyang) VFDs but they are cheap, and work for some people. I have seen posts that the ones with the speed knob on the front panel, also have the braking circuity for an external braking resistor, who knows what else. The GT version models tend to have more program parameters which are often needed to align with the motor specs. If you are going this route then you may consider something like this model with the speed pot, you might request the manual to make sure there are motor adjustments.

A few models from gohz, but more expensive.

Hopefully your compressor is in the 7.5Hp or less range, I would not want to run these VFDs at full output and compressors are notoriously hard on VFDs. I do recall prior posts where they used the HY VFDs for compressors (usually the VFD was oversized), but not sure what model. At a 5 Hp compressor, it is probably more practical to go with a single phase motor.
Mark
 
Thanks for the lead on that CNC drive. Only a few bucks more and I've heard of them.

Yep, 7.5 hp compressor. Right now, I am fighting the startup unloader. Got to get that right or a VFD don't stand a chance.

My single phase 5hp compressor is making a READ BAD sound, don't think its long for this world.
 
I have a VFD just like this one under a different name.
It is on a 5 HP lathe with a two-speed motor.
It works beautifully.

Some things to consider when using a VFD for an air compressor.
  • Does the VFD give full 7.5 KW output with single phase input? VFD output ratings are based on three phase input. In most cases the maximum output is only 59% if single phase power is applied.
  • For an air compressor application, a frequency control knob is not needed. The output frequency will be set at 60 Hz and never adjusted.
  • A braking resistor will not be needed for an air compressor.
  • Tune the acceleration time to work with the unloader. In a perfect world, the VFD will reach full speed just before the uploader closes.
  • Do not use deceleration. Set the deceleration mode to “Coast to stop”. This will take the burden of controlling the motor stop off of the VFD.
  • Be prepared to translate the “Chinese English” manual to “American English”. This can be challenging.
Let us know the trials and tribulations of your efforts.
 
VFD output ratings are based on three phase input.

That applies only to VFDs with 3 Phase plated input ratings, I run multiple machines in a single phase workshop using Siemens, Mitsubishi and Omron drives, all my drives are single phase input models and run 3 phase motors at the VFD rated power without any issues.
 
I'm a little leery of those Mophorn Amazon listings. I remember seeing one for a milling machine and the pictures
they included were of several different machines, and 1 of them was clearly labelled as a PM machine.
I spoke to Matt and he said that it definitely wasn't anything to do with them.

I just looked now and I don't see that milling machine listing anymore. I just don't know if the company is on the up and up...
Maybe someone else has a good experience with them...
 
Some things to consider when using a VFD for an air compressor.
  • Does the VFD give full 7.5 KW output with single phase input? VFD output ratings are based on three phase input. In most cases the maximum output is only 59% if single phase power is applied.
  • For an air compressor application, a frequency control knob is not needed. The output frequency will be set at 60 Hz and never adjusted.
  • A braking resistor will not be needed for an air compressor.
  • Tune the acceleration time to work with the unloader. In a perfect world, the VFD will reach full speed just before the uploader closes.
  • Do not use deceleration. Set the deceleration mode to “Coast to stop”. This will take the burden of controlling the motor stop off of the VFD.
  • Be prepared to translate the “Chinese English” manual to “American English”. This can be challenging

I think you missed my point, although you do not need the braking nor the frequency knob for a compressor (although you may want to run the compressor at a lower Hz for noise reduction), the GT model with the speed pot has other programming functions that may be needed to set the parameters for a 3 phase motor. At least what was outlined by other purchasing these VFDs. There are also some internal differences as to the build quality claimed by the people that sell the GT. These are all rated for single phase input under the technical description, so there is no derating (supposedly). Technical Parameters, with corrected spelling.
Technical Parameters:
1. Input voltage:220V±15%(we also stock 110V and 380V+/-15%,please contact us for item stock)
2. Output voltage:208-240VAC(analogous to input voltage)
3. Input Frequency:48-63HZ
4. Output Frequency:0-400HZ
5. Input phase:1 phase or 3 phase
6. Output phase:3phase
7. warranty:1 year


I did see a comment on the Amazon listing of someone who tried to run a 10 Hp compressor with a HY 10 Hp VFD went up in smoke. Discussion with people that work with VFDs for a profession, and the internals on the HY/generic VFDs does not correlate with their ratings. I would use a fudge factor as to what it can actually deliver on the output. I personally would also use a DC reactor which significantly decreases the THD and prolongs the component life, but assumes something is connected to those terminals. No joke, that is why I mentioned the braking resistor as on some models there is NO connections to the braking terminals. A DC choke also decreases the fusing requirements.
May not look pretty but it is cheap, MTE-DCA004003:


Probably the same vendor, but you may get more leverage with eBay if the VFD fries starting the compressor motor, this one has a 1 year warranty.
 
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