Carrier 38CK030310 Central AC - How to connect motor capacitor?

[ABreese]

The Carrier central AC in my parent's home is ~17 years old, and I want to change the motor capacitor as a preventative measure.  When removing the cover, I discovered there were 2 capacitors installed, as follows:

5uF @ 370Vac   and    5uF/45uF @ 370Vac

The dual-cap had nothing connected to the 5uF tab, and the small cap doesn't appear to be 'factory' - it's laying down on the chassis (not affixed with a clamp), and has some black electrical tape wrapped around the tabs to insulate the connectors.  I suspect the 5uF portion of the dual cap went bad at some point,  and whomever serviced it didn't have a dual cap available so used a 2nd cap because it was handy.

I would like to remove the small individual fan cap and replace the dual cap, but want to ensure I wire it correctly.  The schematic on the cover is old and is not readily readable.  Here's the current connection.

5uF cap has 1 brown wire, and 1 brown wire with a white tracer.  The cap has no markings on it.

5uF/45uF cap has 1 yellow wire © and 1 Blue wire (Herm).  Again, nothing is connected to the Fan tab.

How do I connect this back up using only a dual-cap?  Thanks in advance for helping a Novice!

Alan 

 

[RegUS_PatOff]

I just replaced the GE Fan Motor in my 19yr old  Carrier / Bryant  ($70)

The small single 5uF is for the Fan

My dual Cap was good, but installed the single 5uF along with the Fan Motor,

because my new A.O.S. Motor uses an "isolated" Cap.

Yours may have been replaced along with the Fan at one time.

The 5uF  is about $ 5

the dual Cap is about $ 50 

[ABreese]

Thanks for the quick response.  It's entirely possible the fan was replaced at some point, and thus the 2nd cap.  I just didn't like the idea of having the 2nd cap if I could just use the 5uF portion of the dual cap instead.  I'm sure I can find a clamp to ensure it doesn't vibrate around and potentially cause an issue.

Alan 

 

[RegUS_PatOff]

Your (new) Fan may require the separate Cap

wire ties ... (drill some holes in the chassis)

a dab of silicone glue ..

[Bobice]

[user=20932]ABreese[/user] wrote:

The Carrier central AC in my parent's home is ~17 years old, and I want to change the motor capacitor as a preventative measure.  When removing the cover, I discovered there were 2 capacitors installed, as follows:

5uF @ 370Vac   and    5uF/45uF @ 370Vac

The dual-cap had nothing connected to the 5uF tab, and the small cap doesn't appear to be 'factory' - it's laying down on the chassis (not affixed with a clamp), and has some black electrical tape wrapped around the tabs to insulate the connectors.  I suspect the 5uF portion of the dual cap went bad at some point,  and whomever serviced it didn't have a dual cap available so used a 2nd cap because it was handy.

I would like to remove the small individual fan cap and replace the dual cap, but want to ensure I wire it correctly.  The schematic on the cover is old and is not readily readable.  Here's the current connection.

5uF cap has 1 brown wire, and 1 brown wire with a white tracer.  The cap has no markings on it.

5uF/45uF cap has 1 yellow wire © and 1 Blue wire (Herm).  Again, nothing is connected to the Fan tab.

How do I connect this back up using only a dual-cap?  Thanks in advance for helping a Novice!

Alan    

  Use the dual capacitor and wire as follows. Brown wire to fan side. Brown/White wire along with Yellow to ©, and Blue wire to (Herm). 

[RegUS_PatOff]

[user=3641]RegUS_PatOff[/user] wrote:

Your (new) Fan may require the separate Cap

My replacement AO Smith Motor needed the Capacitor connected across the separate (isolated) Winding.

(I thought)

It seems that some replacement Fan Motors can be wired as a 3-Wire or a 4-Wire  connection.

similar Wagner Motor wiring diagrams

http://sso.diversitech.com/applications/documentlibrary/documents/Condenser_Fan_Motor_TDS.pdf

[Bobice]

 Carrier diagram http://www.docs.hvacpartners.com/idc/groups/public/documents/techlit/38ck-8w.pdf

[ACtechGUY]

I think if you hook that brown wire with the white stripe to the common terminal , something may go poof. If you are using a 3 wire configuration , just simply insulate the brown with white stripe wire and do not connect it to anything.

All motors that have a separate 2 brown wires for the capacitor can be wired this way.

[Bobice]

The wires on a motor is as follows :

From the GE motor man series

Brown wire will have a female flag - fan capacitor

Brown with white  will have a female flag- fan capacitor neutral

Black wire-  power

White wire - neutral (this indicates a 120 volt motor)

Yellow wire - power (220 volt)

Red wire - speed (usually high)

Blue wire - speed

If there is only one brown wire, piggy back the white wire to the neutral side of the fan capacitor.

On dual capacitors the brown with white would connect to the © terminal, where as the brown will connect to the (F) terminal.

No brown wire, this is known as a "resistance-start" motor. seldom used as a condenser motor.