Log in

View Full Version : Ac blower capcitor wiring


jpritch2
Mar 27, 2009, 11:16 AM
HELP!

I just purchase a new FASCO D727 1/2 hp blower motor (old one had some wires burning in it... it smell bad!(

The wires were different colors but after a while I managed to deduce what was what.

Which resulted in nothing happening.

So I called a local electrician, and he came out and took a look.

In the wiring box there was a black linking/bridge wire going from the capcitor to the front hook up panel. Mr. repairman took that out (the bridge)and made the black motor wire go straight to the front panel, he then hooked up the three wires to the front box. It only has three wires hooked up to it , cause it only uses one speed.

On the front the purple incoming wire is now going to the black motor wire.
The yellow wire goes to the red motor wire.
And the white goes to white.

So now the fan comes on , great right? Nope, and unfortunately I did not test with the compressor on, before mr. electrician left.

So the fan blows all the time and the compressor does not come on.

More info - when I bought the motor I did not purchase a new compacitor.
I believe that the black bridge wire goes to one pole of the compacitor (45F272) and then to the front panel, but which pole?

And the black motor wire goes to the compacitor. But I do not know which side of the compacitor to go to. One pole has a red dot and I am thinking this is where it should go?

The capcitor also has two brown motor wire wires connected to each side. One solid brown and the other brown with white stripe. I really just guessed which brown went to which side and put the brown with white stripe to the capcitor pole with the red dot.

I am thinking I had it wired right all along? And need to buy a capcitor to match the new motor?

Any help would be greatly appreciated!!

Jack

Stratmando
Mar 27, 2009, 12:28 PM
Sometimes the motor will have a diagram for capacitor and line connections.
Then the Blower and Compressor hook to the load side of the contactor.
You may also have a pair of wires that can be swapped to reverse rotation.

jpritch2
Mar 27, 2009, 01:14 PM
Sometimes the motor will have a diagram for capacitor and line connections.
then the Blower and Compressor hook to the load side of the contactor.
You may also have a pair of wires that can be swapped to reverse rotation.

It turns in the right direction.

Jp

jpritch2
Mar 27, 2009, 01:20 PM
it turns in the right direction.

jp

Which side is the load side?

I bought a new cap and it does not have the red mark on one of the poles, like the old one did.

Thanks,
Jp

letmetellu
Mar 27, 2009, 01:36 PM
What colors are the wires coming out of the motor. If you will tell me that I will tell you how to connect it up.

jpritch2
Mar 27, 2009, 01:44 PM
What colors are the wires coming out of the motor. If you will tell me that i will tell you how to connect it up.

Brown
Brown w/white stripe
Black
White


There is also a red and blue wire, that I believe are for speed control. They were not used before... I am only running one speed.

There is a cap as well and my new one does not have either pole marked with red as the hold one did.

Thanks,
Jp

wmproop
Mar 27, 2009, 01:53 PM
The 2 browns/,, br and br-white, usually go to the capacitor, one to each side

But like someone else told you the new motor should have wiring diagram on the side of the motor

jpritch2
Mar 27, 2009, 01:55 PM
the 2 browns/,,,,,,,br and br-white,,usually go to the capacitor,,one to each side

but like someone else told you the new motor should have wiring diagram on the side of themotor

Yeah, it just told what wire was for what,. that is not the problem...
The problem is where do they go in the little wiring box that the cap is on?

Jp

letmetellu
Mar 27, 2009, 02:02 PM
This is hard to explain so bear with me. If you don't understand what I am telling you send me another post and I will try again.

The two brown wires with the clips on them go on the capacitor.

The black wire goes on one leg of the contactor after the has gone through the contactor. It may say on the contactor load side.

The white wire goes on the same side of the contactor but on a different pole on the contactor.

I will try to describe better how the contactor works. First you have two wires bringing the power to the contactor, more than likely they will be under two screws. On the other end of the contactor you will have two wires coming out of the contactor that go to different thing, these two wires likely will be under screws also. Each.

jpritch2
Mar 27, 2009, 03:07 PM
I understand.
I will give it a go.

Jp

jpritch2
Mar 27, 2009, 04:01 PM
OK.
I finally got it going..
But now the fan will not start unless I give it a spin.
The first couple of times it came on by itself.

They guy helping me , when questioned about the little bridge wire, which we did not use, said that some motors require 2 wires to get them going.

So that may be the problem
OR

Do new motors need to be oiled in their oil ports before installing or do they come pre-oiled?

Tanks!
Jp

Stratmando
Mar 27, 2009, 04:14 PM
A contactor usually has 2 large wires in(240 Volts), and when energized(24 volts to contactor coil control wires)It makes contact to the load side of the contactor(goes to 240 volts when energized)This connects to Fan and Blower.

jpritch2
Mar 27, 2009, 05:31 PM
Finally figured it out!
When I put the new cap in, it was a wee bit larger... when I pressed it in , a metal tab, lifted one of the connectors off the cap, just enough to lose contact. Duh.
It sure looked on good but it weren't!

Thanks to all!!
It be workin'!
Jp

Stratmando
Mar 27, 2009, 06:02 PM
Kool,
Spinning to run was an indication of open capacitor.
Letmetellyou had good info for you.

jpritch2
Mar 27, 2009, 06:07 PM
Ps - anyone reading this for info... be aware that I also found a relay that had blown out... this relay turned the compressor on and off. Replaced relay and... viola! It work.
Jp

jpritch2
Mar 27, 2009, 06:09 PM
And oh yeah, if you ever do spin your blower to get it running, have the switch turned off when you do so, and then turn the switch on...
Else you could lose a finger! Ouch!
Jp