I ordered a Honeywell model S688A1007 Sail Switch which I intend to wire N.O. to the hot wire on a blower motor (120 volt, 57 watt, 60 Hz, Panasonic FV-20NLF1 WhisperLine 240 CFM In-Line Fan), like a light swith would be wired. No idea about amp draw on this blower. I'm not an electrician and need to know whether my intended use will work or just fry something out.

Sail switch: http://customer.honeywell.com/Honeywell/ProductInfo.aspx/S688A1007

Blower: http://www2.panasonic.com/webapp/wcs/stores/servlet/ModelDetail?displayTab=O&storeId=11201&catalogId=1 3051&itemId=62511&catGroupId=119515&surfModel=FV-20NLF1

Not sure how you will wire but AMP draw is volts/watts so 57 watts is roughly 5 AMPS.

Hmm. There is a lot of info at the sail swith link above, which I don't really understand. Does it look like the switch can handle that load?

It's a simple two wire swith. Can be rigged N.O. or N.C. I want to use it N.O. I was just going to splice it into the hot wire for the blower.

For some reason the link provide does not work for me. Google search pulls up Model=FV-20NLF1. Spec does not provide voltage. If one assumes 120V then 57 watts would be o.475 amps. That is approximately 1/2 amp. Well within limits of switch.

If you are going to wire switch into the hot side of the furnace fan motor why are you using sail switch. Just wire Model=FV-20NLF1 fan into same wiring as fan motor.

If you are going to use sail switch wire it into the hot side of a constant source.

Perhaps you should tell us what the purpose of this fan is and how you intend to use it.

Well. Now I'm confused by different math answers. Lol. Volts divided by watts = amps. Correct? I got 120 divided by 57 = 2.105. That may also be within limits of the switch specs, but there's a lot info depending on what voltage and how the switch is set up. For the blower, the only info in the manual or online is what I mentioned above, 120v, 57w. I'm using it as an in-line AC booster fan, due to poor air flow way down line (it was already poor, but I added another duct to cool the garage/music studio). I want it to come on only when the AC does. I read that wiring directly to the HVAC blower was a bad idea. So, I'm running it off the garage wiring and want to use the switch to turn it on/off (the sail is installed up-line in the duct work, and when the air flows it blows on the sail to flip/close the switch. It springs back to open when air flow stops).

Nope, watts divided by voltage equals amps.

57 watts divided by 120 volts equals 0.475 amps. Well with in the limits of the switch no mater what type of circuit you have.

(Brian just forgot where the decimal point was).

OK, install the inline booster fan, install the fan switch in the duct work some where where you get adequate air flow operate the switch. Wire the hot conductor through the sail switch from a constant voltage source.

There are two ways to wire any switch. You can take power to the switch, put the switch in the hot conductor and then go to the device. Or you can take power to the device, connect the neutral directly to the device. Run a two conductor cable to the switch as a switch leg. Connect the hot to one conductor of the switch leg to go to the switch, come back from the switch with the other conductor which gets connected to the device. Which way you do it all depends on which is easiest and which way requires less wire.

Having the sail switch eliminates the need to run wiring all the way back to the furnace. If you wire from the furnace fan relay you don't need the sail switch.

I would put the sail switch at some place in the duct where I had a strong air flow. If you put it close to where you install the booster fan you might not have enough air flow. If you did, you wouldn't need the booster fan.

I interpreted that as meaning the furnace blower.

Excellent advice... and thanks for correcting my backwards division. Lol. That definitely is within spec. The way you've described is exactly how I've got it set up. Plus, I've run a wall switch (before the sail switch) to kill the whole thing, when not needed (when the garage door is open). I've got the two wires twisted and capped, until the switch arrives. But I can run it with the wall switch, for now. I've got a two story and the ducts I'm boosting are downstairs and accessed from the garage... quite a distance from the upstairs attic. Great flow with the booster fan, though.
Thanks a bunch HK!

Damn. I am clueless. Lol. You've described a few things. All great advice. I've gone power (black) to light switch, to sail switch, to fan (made the most sense to me). The switch will be about 10' up the line in the ducts, before two Y branches. Good flow there.

Great.
One further note, the electrical connection to the sail switch is going to have to be in a an approved electrical box.
My suggestion would be to cut an opening in the duct large enough for the sail switch to pass through. Drill a hole in the back of a handy box or a 4" square box (which ever will cover the hole in the duct). Mount the sail switch to the box and then mount the box to the duct work.

I hope that means power and neutral.

BTW, I was actually talking about the booster fan when I said "blower" (where you quoted me).
OK. One more question. Before I add that switch, would it actually be easier to simply run wire back to the furnace blower rely? I'd read that wasn't a good idea, but I'm thinking sooner or later that switch will still fail (it was designed to be installed at the furnace blower intake, but I'll have it down line getting cold/hot air blown on it) and that it may actually restrict air flow in the duct I install it in (A 5" wide sail in a 6" duct. Maybe I should go further, to where the duct is 10"?). Is wiring to the furnace blower rely beyond a novice?

A 5 by what sail and in a 6 by what size duct? If it significantly blocks the duct it could reduce air flow.

Wiring the fan directly into the furnace should not be difficult. I think I would mount a handy box inside the furnace control area. Run a stranded wire, the same size as the fan motor wires, from the output of the fan relay and another for neutral from a neutral point to the handy box. Come out of the handy box with 2-wire Romex to the wall switch. How difficult it would be to get the Romex to the wall switch, I of course, cannot say.

Tying the booster fan through the relay should not be a problem. After all, its only an additional 1/2 amp. Any self respecting relay should be able to handle that.

Sorry my math is bad today. 120/57= 2+amps.

And I just did it awrong again!! Senior moment!