Fan motor Capacitor / Starter help ??

[Steve Wolf]

I have a GE motor. I have lost the Starter/Capacitor (I dont even know which it uses)

It has 3 Wires for the Starter / Cap. Yellow, Brown, Black.

I have searched high and low for the Wiring diagram or even a mention of this motor anywhere and I cant find anything.

The Tag on the side is very clear as it was purchased by me withing probably 5 years. However the GE plant that made it is gone and GE from what I understand closed that division for small motors.

Can anyone help me with this to get the right Start / Cap ??

Interestingly I cant even find the any GE motor that starts with the numbers "5j" they all seem to be "5k" However the metallic label is clear its 5j.

Here is the info on the label.

GE TWO SPEED Mod 5J722GX

1/4 1/20

V115 60Hz

Protected Thermal Yes

CSA ENCL DP

FR 45 CAR

Type KHC A2.5/2.3

RPM 1725/850

Energy Saver

There is a diagram on how to reverse the motor and how to change the speed. But that's the only diagram on it.

Help solving the Starter / Cap would be apriciated.

Thanks.

[Ken]

You might have some luck searching for the furnace unit and obtaining the blower motor they recommend for the furnace. That might tell you a lot. However my guess is that the cap is probably a 5 mfd 370 volt run capacitor, as that is typical for your motor size. Most do not have a start cap. Also I would measure the black lead resistance to ground to see if it is simply a ground lead. Then the other two would simply attach to the cap leads. Take this advice at your own risk.

[Steve Wolf]

Thank you your help is appreciated.

The old furnace is gone. I had the furnace replaced, I asked the furnace company to leave the motor as I knew that it was new because I had replaced the motor recently. The furnace people left the motor but mysteriously took the CAP. This was two years ago so calling them will be useless.

I took the motor back to the place I bought the motor (an electric motor guy) and he said without trial and error he didn't know off hand what size the cap was, and the company was sold off so he has no reference guides for it. He is the one who said he thought two wires went to the same post. So that is why I suggested it.

Here are my tests.

Yellow, Black and Brown To ground no continuity. (no beep)

However, Yellow, Black and Brown all have continuity to each other. (beep)

And both White and Black power coming into the motor to all yellow, black, brown wires show continuity.

Not sure what that all says. Could two of the Cap wires be common because its two speed motor? And both windings need power to keep the motor running. Low speed and high speed??

BTW the motor starts without the Cap, but then cuts out after a few seconds then restarts, then keeps repeating this.

The cap keeps it running presumably. It also doesnt then need the cap to start, but to keep running.

Thoughts?

[gfretwell]

It probably needs to caps but they are in the same can. The black is the common and the other 2 wires go to each cap. He probably took the cap so you wouldn't know that was all that was bad. No clue to size on either motor?

BTW trial and error without a way to check current is not going to tell you much. They will run with a wide range of caps but not as efficiently.

[Ken]

If this motor is a two speed motor, how many wires total does it have going to it? Two must control the speed.

So you do not have the make and model of the old furnace??? That would allow a search for the parts list.

It would wise to use an ohm meter as I am not sure how little resistance it takes to beep.

If you have only 5 wires going to the motor, I would think the yellow and brown control the speed. If that was the case, then it would be possible that each of those wires could utilize the cap. But they would need to be switched into the circuit. In other words, there must be only one in the circuit at a time, each for a different speed. Then the black lead would go on the other terminal. Unless you get resistance measurements in ohms, you are guessing on what to do. Since you have experimented with the motor, I would get a 5 mfd cap and attach it to the yellow or brown wire. Connect the black to the other cap terminal and see what happens.

Keep in mind that if the motor is not totally enclosed, it might need air flow to keep it from shutting down from overheating. Most motors have thermal protection.

The cap is for a phase shift in the windings.

[Clare Snyder]

Make and model of motor?? What furnace did it come out of? Single speed or 2 speed motor?

[Duh]

Reading comprehension problem? In the original post they stated it is a GE 2 speed.

[Clare Snyder]

Could still be one of about 5 motors - at least - and the "GE 2 speed" motor on my old furnace did NOT use a capacitor the multiple wires were for reversing and hi-low speed. It was a 1/3 1/6 hp unit . Don't have it any more - sold it at my last garage sale. It was for a belt drive blower

[Steve Wolf]

Thanks for your advice.

The old furnace probably has little in common with the new motor. When I bought the replacement motor, I just took the motor to the motor guy and he probably just matched the RPM, voltage and frame of the motor. In fact the old motor was not two speed, the new one was, but the slower speed was never used. It just came with the ability to do two speed.

By the way, I am using an ohm meter, set to the continuity so I tested the R value set at 200 Ohms. Here are my results. Bl-Br 8.2 ohm BR-Y 11.2 ohm Y - BL 4.9 ohm

If I was to get a cap for two speed motor do you think a 40/5 mfd 370-440v would be a place to start for the 120v motor.

Put black on common and yellow on 40mfd post and 5mfd post on brown.

Can anyone point me to link for such a cap. I have seen several on line.

If I blow the motor its ok. This was a motor I was trying to reuse. If I cripple it in trying, so be it. Its not critical to anything, but an anchor if unused. Thanks.

[gfretwell]

That is the cap for a 3HP AC compressor so it is probably too big but I got mine on Amazon Prime.