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4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

I've got 4 wires on a fan motor, red, black yellow and brown.
It is a 230 v motor.
I'm fairly sure the red and black ar the power wires.

The nameplate diagram is not legible.

Any idea where the yellow and brown wires go?

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

Honestly, it's dangerous to tinker with electricity if you are not sure. Please ask for help from any electrician in your area. We can't even figure out what motor you've got! Sorry.

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

This is a standard application which exists on nearly every residential A/C condensing unit in the US.

It is a capacitor start motor, single phase, 1/2 hp, 230v.

I replaced the bearings and it should be ready to go!

With no legible nameplate drawing, a local electrical guy would probably not have more insight than an electrical guy on a forum, who works with these motors routinely!!

So the remaining question is, if the red and black are power wires, where do the remaining 2 wires go in a capacitor start application.

I expect that one goes to 'F' on the capacitor and the other to 'C' on the capacitor. Obviously we'll stay off of 'H'.

Not looking for a guarantee, just a description of how this kind of motor usually connects.  Tips appreciated.

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

Hi etbrown,

Unfortunately, they're not all the same -- I can tell you from experience.  I have replaced condenser fans with purple wires, and consensing fans with red wires.  As for your capacitor, normally the terminals are: H is hermetic (the compressor), C is common, and F is fan.

If you don't have the model number of your unit, with which you can probably find a wiring diagram online, at least look for a diagram from a similar model of the same manufacturer. I really can't guess you a wiring diagram by wire color.

I also recommend that you have someone experienced look at it in person.  We're engineers on this board.  If you must, there are plenty of here's-how sites that you can find by googling "condensing unit capacitor terminals." Again, I don't recommend it, but there's even an e-how video that shows up.

At the very least, don't assume that the wire color corresponds to what you see in a wiring diagram that is not for your particular unit.  Follow the wires back to their origins to determine what they come from.  Red may not be line, it may be from one motor or the other.

Good on ya,

Goober Dave

Haven't see the forum policies?  Do so now: Forum Policies

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

Thanks for the tips...

In the suggested Google search, I found the following.

Though I'm sure there can be exceptions and variations, is the following, something that sounds reasonably typical or standard?

"The standard color code for a universal multispeed reversible a/c condenser motor is:

White = Common
Black =High Speed
Blue = Medium Speed
Red = Low Speed
Brown = Capacitor

Occassionally we find a second capacitor wire:
Brown with white Stripe = Capacitor common

Purple & Yellow for changing rotation."

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

Hire somebody or there is a 3:4 CHANCE you will be paying for it again!!

Should have marked it when you took it out.  Good thought for next time!

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

Do you have any idea who manufactures it? If not, who is the manufacturer of the A/C unit?

RE: 4 wires on a fan motor, can you help a 'mechanical' guy? elec questi

I second MiketheEngineer

You really should mark the wires when taking them out.

Or do as I always do, take pictures of the connection to your unit before disconnecting anything.

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