I have an Emerson furnace blower (5 speed, 10 amp, 115V, 3/4 hp). I am looking for a switch to at least operate 3 speeds and how to connect it. The wire colors are white, black, yellow, blue, red, and brown. In addition I would love to put a timer in-line. The model number is K55HCNNZ-7057 for the motor. I've been searching all day and not much of an electrician, but learning. The Emerson Motor Division site wasn't much help. Seems like I should be able to utilize a 10 Amp ON-Off-ON toggle switch in some way at least to get a couple of the available speeds. Any help would be appreciated.

Just in case you're wondering, I am trying to make a homemade shop air cleaner.

Thanks for any help.

You can buy a double pole double throw toggle switch and that would operate two of the speeds but it would have to be a switch that is rated at least 15 amps and you would also need to put an inline fuse int both of the speeds that you will be using. If you are using this just to blow air with out any resistance you will have to cover part of the outgoing air space or it will overheat from the load.

Double throw, center off switches are fairly common even in the amperage you need. Hardware stores should have multiple pole switches giving you several speeds. They may not be heavy enough for your load. You may need to go to an electrical supply.

I'm hoping a couple of filters on the intake side of the case will create enough static pressure to simulate normal conditions. Never even considered the inline fuses. Thanks for that heads up. I've got a call into a local electric motor company. Hopefully they'll have a source for a multiple switch set up. Otherwise, do you think 2 of those On-Off-On switches could be wired to give 4 speeds? Thanks again. You're a great help.

If you want to trust yourself not to select 2 speeds at the same time, you could just use a bank of single throw switches. Actually some motors are set up using different combinations of winding for different speeds.

You can buy relays that would be able to provide you with the four speed selections that you want but they operate off a 24 volt coil and therefore you would have to have a 24 volt transformer and some sort of dial switch like on a box fan that would have four speeds. And as I think about it you might not even have to have the relay only the dial switch if it would carry the amp load that you need.
Now about the filters that you plan to use. I am not sure that two filters will give you the restriction that you would need, you would just have to use a amp meter to load up the motor to meet it's specs. If you need more restrictions just cut a pice of metal to close up part of the discharge throat. In fact it could be that you already have one on your blower that will move, it just a minor movement to of it to match the specs. Good luck.

That's a good suggestion for the additional restriction. It's pretty much wide open, but I was planning on incorporating some adjustable louvers anyway. As for the filters, there would be one course, then a pleated 1 micron bag filter, maybe HEPA. Also, I was going to place the intake for both squirrel cages about 3-4 inches from the sides hoping that would restrict the flow as well.

Regarding the switch, I have some news to report. Talked to a guy at work that told me about a company called Newark. Found them on the web and they have a 6 position rotary switch rated at 15 amps for $30. Was happy to find one. I was on my way to the multiple throw route when I found it. Actually have 3 toggle switches in the car to take back. BTW, this blower has a transformer attached to it.

Thanks again for all the help. Hope it was an interesting question anyway. Hopefully I've got this licked and it's just a matter of building the dang thing.