Hi
I have a fan on a large AHU that is shuttering at approx 60% speed, has anyone ever experienced 'stall' on centrifugal fans? Both pulleys new, belts new and definantly aligned.
Anyone input would be appreciated!
Printable View
Hi
I have a fan on a large AHU that is shuttering at approx 60% speed, has anyone ever experienced 'stall' on centrifugal fans? Both pulleys new, belts new and definantly aligned.
Anyone input would be appreciated!
So bunda,Quote:
Originally Posted by bunda
Do you mean it vibrating like it's out of balance?
Can only suggest you check fan blades intact, clean & not damaged.
Check drive shaft is running true, as well as fan wheel.
All supports & structure of it secure.
Could also require balancing.
If you speed it up past 60% does it come good?
So running on a variable speed drive, up to 30hz fan runs perfect, between 32-35hz I have this issue then as it runs higher it corrects itself again.
Is it the fan, the motor or the inverter that is causing the problem?
maybe slow down the ramp up time- check the inverter is prog correctly for the motor size,rpm,flc etc- run it in hand at 50htz to test it
http://www.pump-zone.com/topics/moto...-and-solutions
Suggest skip the frequencies causing the issues.
A large backward curve centrifugal will stall overload if discharge air is blocked or restricted.
Had an issue like this on a trane unit, new inverter sorted it