Ac motor has a white, a black, and a blue wire. What is the blue wire for?

Need more info

There should be a wiring diagram on the motor plate.

There should be a wiring diagram on the motor plate.

There is absolutely no writing at all on the motor. There's a little Japanese scribble on the capacitor and that's it.

need more info

Wish I had more info, but that's all I can supply. I have not run across a motor before with the blue wire.

Could be a second speed. Like white/black speed #1, white/blue speed#2

Or blue could be for a capacitor. What's the resistance of the windings? i.e. combinations.

What's the application?

Could be a second speed. like white/black speed #1, white/blue speed#2

Or blue could be for a capacitor. What's the resistance of the windings? i.e. combinations.

What's the application?
Sounds like some possibilities to try. The capacitor is already connected in the circuit. I think the motor came from a piece of equipment, maybe a grinder or drill press. Unsure. I'll check the resistance on the windings. Thanks for your input.

Wish I had more info, but that's all I can supply. I have not run across a motor before with the blue wire.
So you have No Idea what this motor is for. Is it not working?
You need another speed?
Needs to work on a Different Voltage?

So you have No Idea what this motor is for. Is it not working?
You need another speed?
Needs to work on a Different Voltage?
I believe that it came off a grinder. After checking the resistance, which another guy asked if I had done, I found that I was reading infinite resistance on the plug in. That always sounds like a broken winding or a loose wire. Found that it had a broken wire in the windings. Fortunately, it was on top and close to the lead in wires. After soldering it back together, I ran through the usual "swap the wires around" until I finally came up with a running solution. The white and blue wires tie together and go to one lead in wire. The black wire hooks to the other lead in wire. Now I have a screaming little "grinder" motor or whatever use I need it for. Thanks for the info everyone. It solved my problem.

Good Deal.

Good Deal.

Well, I thought that too, until I let it run a while. Then that awful smell started, followed by the smoke. Now I'm back to square one. Oh well...

When you said this, "Now I have a screaming little "grinder" motor or whatever use I need it for".
I was thinking "Screaming" in not always a good thing for a motor.
You learned something.
Sorry to hear, take care.
I had this thought in the back of my mind

When you said this, "Now I have a screaming little "grinder" motor or whatever use I need it for".
I was thinking "Screaming" in not alway a good thing for a motor.
You learned something.
Sorry to hear, take care.
I had this thought in the back of my mind
Well, I thought this was going to be a hopeless case, but I decided to try a few more ideas and blow me down, I finally figured it out. The black and blue wires hook to the line and the white wire is a "starter" wire. It can be wired in with a momentary switch and all will work like a charm. I actually let it run for at least 5 minutes this time and no smells and no smoke. I think I finally have myself a good working little motor. If anyone else out there runs across a motor with similar wiring, this could be your solution also.

The "starter wire" can be replaced with a "starter cap". So it looks like you have a capacitor start, capacitor run motor.

The "starter wire" can be replaced with a "starter cap". So it looks like you have a capacitor start, capacitor run motor.
Yeah, the capacitor was already wired in the circuit. All the ac motors of this nature that I had ever messed with, had only the standard black and white wires. The extra blue wire was giving me headaches trying to figure where it went. Using the blue wire as one of the mains and the white as a starter works fine, so I guess I'll stick with what is working. I really need a centrifugal switch to kick the white wire out of the circuit as soon as it starts. I had some old three wire motors that worked that way, but the starter wire was never really exposed. It was inside the motor housing. It will be very easy to add a momentary switch to the circuit, soon as I figure out what I want to use the motor for.

You missed my point: 1 motor, 2 capacitors. 1 start and 1 run cap.

See: http://www.starite.com/pentekmotors/Assets/P8098TB_SMC_CSIR.pdf

Usually you think one OR the other or a dual capacitor in a single unit.

You missed my point: 1 motor, 2 capacitors. 1 start and 1 run cap.

See: http://www.starite.com/pentekmotors/Assets/P8098TB_SMC_CSIR.pdf

Usually you think one OR the other or a dual capacitor in a single unit.

Yes, I did miss the point, but do NOW understand. Thanks for the info. I am just a tinkerer, so sometimes I'm slow to catch on. How would the second cap be wired in?

Read this: http://www.stearns.rexnord.com/pdf/Cat_902/Cat_902_table.pdf

It's very similar to a "hard start kit"

The capacitor acts as an initial short, thus starting a motor. Note the "OR" in the ref in past #16.

Does the motor run if you connect only 2 of the 3 wires? Try all combinations.

If you want to avoid more smoke, wire the motor in series with a 300 watt bulb for testing purposes.

Most electrical devices run on smoke. Once you let the smoke escape they don't work any more. Buying new smoke for them can be very expensive.