Has anyone actually installed & run one of these fans ? I replaced mine last night & the new one made a moaning noise which varied in intensity with the fan speed control - sounded like some sort of harmonic oscillation - caused by the stove's speed control circuit. So I wired it directly to an outlet - no more noise - lot more air - Even on high, the DVC's controller must still be applying some speed control. All P/N's are exactly the same, but Grainger themselves note: Not for use with speed controllers?
I'm leaving it in, directly plugged into the main. I always considered the distribution on the DVC a bit lame - now my problem is solved!
from the electric motor warehouse website: "Note Regarding Speed Controls:
With more and more people using wood burning stoves during heating of some issues surrounding the speed controls that vary the air output from centrifugal blowers. On a single speed blower, a speed control wired in series with the hot line will allow the user to control the speed of the blower. Many speed controls will not lower voltage below 60 and will not allow the wheel to slow to 0 RPM. Also, the combination of a blower and a speed control can often result in what is called “harmonic noise” – strange vibrations and/or noises in the customer's unit. Slightly increasing or decreasing the blower speed can sometimes eliminate this problem – but it is often not 100% removable. "