No air in the blower outlet duct
Thread Content
When a heater blower is operating normally, there is no air pressure at its outlet; the motor current is 24A, while that of the other blowers is 37A (under the same operating conditions and with the same type of blower). What could be the reason for this? Note: The fan blades have been inspected and are in good condition; there are no abnormalities in the operation of the unit.
Not a bit? Is the inlet blocked? Check the inlet.
The operating current of the motor is lower than that of a fan operating normally, indicating that the motor’s load is low. The reason may be an obstructed air duct, such as insufficient valve opening ； The separation of the valve stem from the valve flap results in the valve flap not opening ； Foreign object blockage, etc.
I think the reasons are as follows: 1. The fan rotated in the reverse direction (this has also happened to us). 2. The shaft broke (this has happened to us as well; at that time only the shaft was rotating while the impeller had fallen off!) It was caused by corrosion of the nitric oxide fan, which led to the shaft breaking at the root of the bearing journal. 3. The air valve was not opened. 4. The person who tested the system felt numb: lol. This post was last edited by ddfmy on 2009-3-27 at 11:48
The root cause of the problem has been found! It was caused by the damper in the blower’s outlet duct closing on its own. Thank you to everyone above for their analysis.
Although the problem has been resolved, it is logical to note that: 1. The location of the sampling point is a prerequisite for analyzing the causes; 2. The back pressure of the fan is also an important factor affecting the outlet pressure
Closing the outlet duct damper will not result in no air pressure; check again! ! !
Thank you for the reminder from above. The outlet air duct is closed during operation, resulting in very low back pressure, which is indeed difficult to detect by hand.