Originally Posted by
Wade Lippman
That is totally intuitive. The more constriction means less air flow means less amp draw. That is the exact opposite of what you are saying.
A DC uses the most current, and moves the most air, when you remove the ducts and filter; and it uses the least current and moves no air when you put something over the intake.
Dale,Wade, and Art are in agreement. Every one is right. You can prove this for yourself by putting amp meter on your shop vac. Measure the current it draws, then block the intake with your hand, you will see the current decrease. It's not a centrifugal fan, but it's the same principle. Some folks are fooled because the sound from the motor/fan really starts to scream. The rpm increases because there is less air to move, but the current goes down. Dale has fought this battle before.
Last edited by william watts; 09-30-2015 at 11:44 PM.
Bill
" You are a square peg in a square hole, and we need to twist you to make you fit. " My boss