carrier ac air handler control board

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Old 10-21-13, 01:27 PM
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Question carrier ac air handler control board

Can anyone explain how to connect an hk61ea006 control board to a FC4CNF048 carrier
system? An AC tech provided a temporary fix by bypassing the on-board relay and wiring up a relay to allow the fan to operate. It will only work for AC, though, and with cold weather coming, I need to make sure the heater will work too. I now have the control board, but don't know how the original wiring was connected. Does anyone have a photo or wiring diagram that might describe how the original wiring was/should be connected? Thanks for any help!

-JD
 
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Old 10-21-13, 02:18 PM
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By the way, I think I only need to know how to connect the NC, NO, and SPT connectors for the fan relay. The only other connections are the 6 pin bus which I expect did not change. I can probably provide a pic of the current relay bypass if that would help. Thanks!
-JD
 
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Old 10-21-13, 03:23 PM
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http://www.docs.hvacpartners.com/idc...it/fa4a-1w.pdf

Refer to the diagram on your blower housing.
I usually see Sequencer black to NO, Sequencer blue to NC, Fan blue to SPT.

 
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Old 10-21-13, 04:26 PM
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Thanks Houston,

I studied it for a while yesterday, but couldn't figure it out. Looking at your schematic diagram, along with your spelling it out, it makes sense now. It's the in-laws unit, so hopefully I can regain some modicum of respect if I can fix it this weekend!
Thanks again!

-JD
 
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Old 10-21-13, 04:53 PM
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The diagram in the unit can become hard to read after a while.
It's always easier for me to read a digital copy that I can zoom in on.
 
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Old 10-22-13, 04:21 PM
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Here are some pics

Here are pics of the blower housing diagram, the control board, and the relay used to bypass the control board so that the blower works. I can't see any reference in the diagram that indicates how to connect the relay on the control board. I have a new control board, but don't know how to connect the relay... Any help appreciated.
Thanks!
- JD
 
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Old 10-22-13, 08:16 PM
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Turn off power to the unit. Find the sequencers for the heat. See if there is a blue wire and a black wire that are not connected to anything and taped off. If the black wire coming from the sequencer is loose that wire will connect to NO terminal on the fan relay on the board. If that wire is not loose find the black wire coming from the 240V side of the transformer and see where it is connected.

Black wire from sequencer (or transformer) goes to NO terminal
Blue wire from sequencer goes to NC terminal
Blue wire (or whatever color wire for the speed you select) from blower motor goes to SPT terminal
 
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Old 10-22-13, 10:42 PM
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The high voltage connections I can do from those pics.
The 2 low voltage light blue wires to the bottom of that temporary relay might require a few more pics.
 
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Old 10-22-13, 11:07 PM
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ABCD
16 pin connector
ECM motor
I see why you couldn't figure out the wiring from the diagram on the unit...
Someone stuck the wrong diagram to the blower when they installed the heat strip.
 
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Old 10-23-13, 06:48 AM
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Can you trace the two blue wires circled in the photo and tell us where they go?
 
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Old 10-23-13, 04:04 PM
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More Pics

OK, Finally got another picture. One of the light blue wires goes into a juction box and wire nuts with a white wire and a thin green wire. The other light blue wire goes to the transformer on the same contact as a brown wire. I have pics of the actual connections if needed.
 
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Old 10-23-13, 06:11 PM
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It's just G and C.
I have wired a temporary relay in this manor before.
You should be able to eliminate these 2 wires.


The thin Green wire "G" from the stat should connect to a grey wire in the air handler, not white.
 
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Old 10-23-13, 09:42 PM
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Ok

So, the blue wire currently connected to NC stays there on the new board, black and dark blue from the bypass relay go to NO and SPT respectively. And I just remove the other two blue wires completely, leaving only the grey(I think the flash from the camera made it look white) and thin green in the wire nut. Please let me know if I'm missing anything, and thank you once again Houston204.

Thanks to you too firedawg!

-JD
 
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Old 10-25-13, 08:20 AM
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NO--Black wire
NC--Blue wire (to sequencer)
SPT--Blue wire (blower motor lead)

The other two blue wires are removed from the wire nuts.

Please let us know if it works for you.
 
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Old 10-25-13, 05:42 PM
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Thanks, will do. I plan to do it tomorrow around 10:30am.

Is there any reason the repair tech would have made any other connection changes? I'm assuming I only need to wire the relay on the new board, and the bus connector will just attach to the new board same as the old...

-JD
 
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Old 10-26-13, 01:08 AM
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An AC tech provided a temporary fix by bypassing the on-board relay and wiring up a relay to allow the fan to operate. It will only work for AC, though
Seems like your heat should still have worked. (If the stat was configured for electric heat)

The heavy white wire in your air handler low voltage j-box should be connected to the stat "W" wire. (Usually a white wire from the bundle that also connected stat green to air handler gray.)

 
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Old 10-27-13, 08:28 AM
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Good eye Houston204

I didn't see your post until I had already arrived (about an hour drive). We tested the heat and it did work. AC repair guy said it was a temporary fix and would not work for heat. Also wanted a ridiculous amount to replace the control board. $600 for the board alone (which I found online for $50). So I guess I'll keep the control board in case the temp relay fails sometime down the road. At least I know how to connect it now. Thanks! Probably need to find a trustworthy AC guy in the San Marcos TX area also, just in case they need some immediate service again...
 
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Old 10-27-13, 09:57 AM
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The electric heat strips will age much faster unless the fan controls are corrected. They have a delay before shutting off that the fan would not have.

You could verify that fan blue is connected to NC on the temporary relay, power is at N.O. and connect sequencer blue to NC.

I would install the board that you have already purchased.
 
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