How many capacitors should A 40W fan have?

Start with a selection of perhaps 4 capacitors. For a 40w fan one might try a selection of values from 1.5uF down to maybe 0.7uF. There is no reason to use the maximum 2uF, as this would give approx full speed, whereas we only need capacitors to provide the reduced speeds.

How does a fan controller work?

These use electronically controlled triacs instead of capacitors, and effect on fan speed does not depend much on fan characteristics, so a single controller can be used with a wide range of fans. Fan speed is reduced by placing a capacitor in series with the switched live feed to the fan reduce power. The capacitor acts as a dropper .

What is a draft inducer blower?

In terms of drafting, a draft inducer blower provides sufficient draft (just like the chimney in your fireplace that provides a draft), for clean and safe combustion. This clean combustion prevents burners from getting clogged with soot over time and creates a more balanced pressure in the combustion chamber. Problems with a Draft Inducer?

Are capacitors rated X / Y rated?

The capacitors need to be 600v rated (or higher). 250v caps are inadequate for even brief use. 400v caps might or might not suffice, so are not the best. Electrolytic capacitors are polarised, and completely unsuitable. Capacitors need not be class X or Y rated, since capacitors failures are inherently safe with this controller.

Is a fan a part of an inducer blower?

You’re probably not surprised that a fan is a part of the inducer blower (other than that “B” word in there!), because you can actually hear the inducer fan whirring in the 30-60 seconds and blowing air before your furnace roars to life each time it runs. Unfortunately, these assemblies are one of the most common parts to fail on a furnace.

What are the different types of fan controllers?

The other type of controller available is a universal fan controller. These use electronically controlled triacs instead of capacitors, and effect on fan speed does not depend much on fan characteristics, so a single controller can be used with a wide range of fans.