Help with air handler LV wiring

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Old 07-17-10, 10:29 AM
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Help with air handler LV wiring

I have a Trane TWE031E130 air handler. It has an internal heating element for occasional cool days here in South Florida. The unit has the Ylo terminal on the low voltage panel connected to the "W" (heat) terminal on the thermostat. According to the schematic the "W1" terminal on the low voltage panel should be connected to the "W" on the thermostat. All other connections are as expected. Even though the heat works as it should, I am concerned because I want to make some modifications to support a humidistat. Any help would be appreciated.
 
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Old 07-18-10, 06:18 AM
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What do you have for the outdoor unit?

At the air handler, is there any wire on the W's?
 
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Old 07-18-10, 06:43 AM
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Originally Posted by Jay11J View Post
What do you have for the outdoor unit?

At the air handler, is there any wire on the W's?
No, all 3 terminals are open.
 
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Old 07-18-10, 07:05 AM
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I don't understand how you can get heat if W's are not wired up.. W's is your heat, and Y is blower speed for cooling.... ???

Unless something is messed up behind the board...
 
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Old 07-18-10, 07:39 AM
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Originally Posted by Jay11J View Post
I don't understand how you can get heat if W's are not wired up.. W's is your heat, and Y is blower speed for cooling.... ???

Unless something is messed up behind the board...
That is why I am asking the question. Also note the heat is connected to Ylo not Y. I haven't gone behind the lv terminal board yet. Perhaps the installer did some special wiring. I find it odd because everything is standard Trane including the compressor. BTW the thermostat is a Honeywell CT3400A100, using 4 wires (term. R+Rc jumpered,W,Y,G ).
 
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Old 07-18-10, 08:16 AM
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For kicks before you tear everything apart, move the wire to W and see if you get heat.

what are you planning on using for dehumdity control?
 
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Old 07-18-10, 09:14 AM
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Originally Posted by Jay11J View Post
For kicks before you tear everything apart, move the wire to W and see if you get heat.

what are you planning on using for dehumdity control?
I was thinking of trying that, but I don"t want to break anything. I expect that the worst that can happen is "no heat", do you agree?
I am planning on adding the Honeywell Prestige thermostat which has built-in humidistat. It can be configured to run as A/C mode with normal fan or low speed fan mode. I would prefer the low speed fan because the winter months don't need much cooling but do need humidity control. Low speed mode is where the wiring becomes the issue.
 
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Old 07-18-10, 09:42 AM
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Ok, I'll be happy to help you with the wire hook up when you get it.

Do you have extra wires in the walls for this?

No harm is done, just no heat. You know how many banks of heat strip you have? I am guessing maybe one.
 
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Old 07-18-10, 12:19 PM
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Originally Posted by Jay11J View Post
Ok, I'll be happy to help you with the wire hook up when you get it.

Do you have extra wires in the walls for this?

No harm is done, just no heat. You know how many banks of heat strip you have? I am guessing maybe one.
I'm looking at next weekend for this project. I have a 5 conductor low voltage wire running to the thermostsat, only 4 are being used. The new thermostat has a "wire saver" device which allows you to put the fan and cooling wires together into a single wire. This will give me an effective 6 wires to work with.

Thanks for the offer to help. I don't want to use the contractor because not only are they expensive, but I don't trust them to send someone who understands "why" things are connected the way they are. Also I enjoy doing it myself.

I assume only 1 heat bank since this is south Florida, but I don't know for sure. Would it be safe too assume 1 since there is only 1 heat connection?
 
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Old 07-18-10, 09:48 PM
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Ok, with "6" wires.

I'll get into more details where the wires goes when you get the t-stat.

I am guessing you have single stage A/C?
 
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Old 07-18-10, 10:15 PM
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Originally Posted by Jay11J View Post
Ok, with "6" wires.

I'll get into more details where the wires goes when you get the t-stat.

I am guessing you have single stage A/C?
That is correct, 1C/1H system.
 
 

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