Speed control for shop fan.

wearymicrobe SuperDork
9/26/15 3:52 p.m.

Need to slow down on of these monsters that I use around the shop and the house. Basically having it blow solder fumes away from me when I am doing wiring in a motor. There are no fans available in San Diego due to the heat wave and I would like to pull it in the house after I am done and keep some fresh air coming into the house after I am done using it in the garage.

http://www.harborfreight.com/30-inch-pedestal-shop-fan-47755.html

Motor is 1/2 HP and says not to use a solid state speed regulator which is weird unless its 16 pole wiring. Is there a cheap answer to this, the thing at low speed moves something like 5000cfm and its loud as heck. I can live with say 50% reduce motor life as these things last years around the show and only tend to beak when I do something stupid like drop them. A fire from the motor burning up less acceptable.

I am sure tha anser is a variable frequancy drive

Agnew UltraDork
9/26/15 4:37 p.m.

I imagine the cheap answer is just buying a fan off the internet and picking it up somewhere.

Screwing with fan motors is a good way to end up buying another fan.

T.J. UltimaDork
9/26/15 4:39 p.m.

I too have that fan. It pretty much sounds like a Cessna is taxiing for takeoff when I use it. I am interested in seeing responses to this thread.

T.J. UltimaDork
9/26/15 4:45 p.m.

Wonder if this would work?

Toyman01 GRM+ Memberand MegaDork
9/26/15 4:57 p.m.

T.J. wrote: Wonder if this would work?

No. That is for brushed motors only.

A VFD might work, but I'm betting the motor would smoke pretty quickly.

wheelsmithy GRM+ Memberand HalfDork
9/26/15 5:08 p.m.

Rheostat? Wire it to a light dimmer from Lowes?

novaderrik UltimaDork
9/27/15 1:20 p.m.

wheelsmithy wrote: Rheostat? Wire it to a light dimmer from Lowes?

too cheap and easy...

1988RedT2 PowerDork
9/27/15 1:30 p.m.

The description for that fan claims it is a three-speed motor. Check the label of the motor carefully. It may contain instructions for switching a couple of wires (located under the wiring cover plate on the motor) and using the low speed windings.

Edit: Never mind. I just read the user manual. Apparently the fan has a 3-speed switch operated by a pull chain? Are you currently running on low speed?

motomoron SuperDork
9/30/15 9:30 p.m.

I've got an even larger Taiwanese made one. The 3 speeds are C-130 on takeoff roll, C-130 cruise at altitude and C-130 on descent. It was nice when it was 97 F at 98%, but now it's just crazy annoying. I'll pop the rear cover off to see what the wires are up to.