Squirrel cage blower

[Bruce09]

I am very close to completing my shop build and this SC heat is unbelievable. I picked up a gas furnace blower to make a shop fan. The guy said gas was the only fan that'd run on 110. It was free and works perfectly after I repurposed an old pressure washer cart. I mounted it on the cart and ran black to black, white to white, green to the motor casing and holy hurricanes, this thing will really put it out. It's a little too much actually, so I started tracing wires and found two brown wires, to capacitor, and a red, low, and blue, medium speed, and black is high. My question is this, I want to mount a switch on top of my cart to change speeds because with it on high, it almost blows my dog away, lol.. All I can find is a pull cord for a ceiling fan, I'm sure they make one but I just can't seem to locate the name of it or who'd make it. I asked the guys at home Depot if they had a three speed fan switch and I was led to the string pull cord. I may be crazy but I'm thinking there should be a switch I could wire up red, blue, black, white and a ground and just turn or toggle through the different speeds, any help would be appreciated..

 

[Reach4]

The switch you are looking for would be a SP3T (Single Pole 3 Throw) or SP4T switch. With the SP4T switch, one of the positions would be off. Make sure you find one rated to switch enough current. You could spend a lot, but if you look I expect you will find something reasonable.

I don't know where you can walk in and buy such a switch locally. There is also a way to use 3 regular "2 way" switches for high med low off. The operation would not be obvious to a stranger. This is a schematic of the 3 switches:

You can mount those into a 3 gang electrical box.

If you just wanted High and Low, you could use a single such switch plus another switch for on-off.

 

[Sponsor]

 

[DonL]

You could use one of these, It would give you 2 speeds and off.

I would put guards on the blower so the dogs tail or your fingers do not get shortened.


Good Luck on your project.

 

[Bruce09]

Very good, I found this photo and I believe it's what ur talking about in a three gang box? One single and two double light switches? I like that small toggle Don, I guess a low and medium would work fine. No worries on the dogs tail, it's been gone.. Lol.. I do have an 8 ur old running around so I'm gonna put some expanded metal over it.. The wires coming out of the fan is 16 or 18 awg but the insulation is larger than normal wire I've dealt with. I have some 12awg wire in armoured cable I could use for a plug, I've been using a 15ft drop cord and the wire isn't hot but the fan motor gets pretty warm. Should I be using a heavier wire than the 14 gauge drop cord?

 

[Reach4]

Very good, I found this photo and I believe it's what ur talking about in a three gang box?

Similar. That configuration is probably better.

 

[DonL]

You are making things to complicated. Looks like you are building a Start Sequence launcher for a Rocket Motor. No Rocket Science needed here.

Just use a 4 position switch if you need all 3 speeds, Why would you use 3 different switches ? I would not do that, No need.

One thing that may be hosed in your app could be motor cooling. A hose can help when you are hosed.

You can mount a 3/4 or 1 inch hose on the output air path of the blower, and redirect the air to blow in/on the motor for cooling. I have done that and it works good.

Do not forget the fuse. And be careful playing with electricity. A shocking experience is a very quick teacher.


Good Luck.

 

[Bruce09]

That is a complicated way to have access to a four way switch Don, that's why I asked. Common sense told me I'd need a switch like that but nothing is available around here. I did make it simpler, I bought a pack of male/female blade plugs, the ones you crimp onto the wire. I'll just plug my supply hot to whichever speed I want, no switches just three female plugs one male. A rocket motor huh? Hmm.. Never know...

 

[DonL]

You can get 1 switch that will do it. Digikey may be a better choice. Or Military surplus.

Sounds like you have it under control.

What size fuse did you use ?


Enjoy.