Comressor-VFD Setting Speed
Comressor-VFD Setting Speed
(OP)
The compressor minimum speed is 60%Nominal Speed. We need to set VFD to drive the compressor. I am thinking of setting VFD minimum speed at 30% Nominal Speed. Since we may run the compressor at lower speed later. Anybody can shed some light on me?
Thanks in advance.
Thanks in advance.





RE: Comressor-VFD Setting Speed
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Comressor-VFD Setting Speed
RE: Comressor-VFD Setting Speed
RE: Comressor-VFD Setting Speed
as jraef points out, the minimum speed is determined by the mechanical limitations of the system and the recommendations of the manufacturer. A lot depends on lubrication and the impact of running at low speed.
RE: Comressor-VFD Setting Speed
RE: Comressor-VFD Setting Speed
RE: Comressor-VFD Setting Speed
RE: Comressor-VFD Setting Speed
Will the compressor manufacturer honour the warranty? Probably not.
Will it break? Probably.
It's your compressor; do what you want provided it remains compliant with the applicable codes, but the manufacturer usually sets these limits because they are safe for the machine.
----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: Comressor-VFD Setting Speed
If only more people recognized that simple fact...
"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> FAQ731-376: Eng-Tips.com Forum Policies
RE: Comressor-VFD Setting Speed
As others have said, you can set the VFD minimum speed to whatever you wish but on a reciprocating compressor, this is not a good idea.
The company I work for manufactures both VFD's and recip compressors for refrigeration. Our minimum speed is 40% of rated speed (30Hz on a 50Hz supply and 36Hz on a 60Hz supply). This is specifically for oil regulation. Maximum speed is also limited but for other reasons.
I would stick with the manufacturers advice otherwise it will get very expensive when it fails, and it will fail.