Why Is Your Centrifugal Fan Outlet Pressure Too Low?

Insufficient outlet pressure of a centrifugal fan? Don’t rush to replace the equipment. Check the following points in order:

1. Wrong rotation direction
   (Most common issue after new installation. Simply swap any two phases of the power supply.)
2. Insufficient speed
   (Check for belt slipping or frequency/speed limitation from the VFD.)
3. Excessive system resistance
   (Check for clogged filters or valves that are not fully opened.)
4. Blocked air inlet
   (Check the inlet filter and duct for foreign objects or blockage.)
5. Excessive clearance between impeller and inlet cone
   (Large clearance causes internal air leakage, reducing pressure performance.)
6. Low gas density
   (Caused by high-temperature operation or incorrect gas conditions.)
7. Leakage in the outlet ducting
   (Check weld seams, flexible connections, and other possible leakage points.)
8. Impeller wear
   (Common when conveying dusty or abrasive gases.)

Recommended first check: motor current.

• Low current + low pressure: Check rotation direction, speed, and inlet blockage.
• High current + low pressure: Check outlet blockage or excessive system resistance.