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trane thermostat question

4K views 11 replies 6 participants last post by  TheBigDog 
#1 ·
I am trying to figure out trane thermostats on a typical trane heat pump is


R has 24 v
G has 24 v
B is common
Y is compressor
O is reversing valve and is energiezed in cool
W2 is second stage heat
E is emergency heat

is this right please advise
 
#2 ·
Hi NCSteve

The thermostat nomenclature you have is partially correct. This is how most thermostats for heat pumps operate. You need to first understand the input and output terminals.

R= 24 volts power
Y= 24 volts output either cool or W1
G= 24 volts output to blower
O= 24 volts output reversing valve
W2= 24 volts output auxillary heat
E= 24 volts ouput auxillary heat
X= 24 volts common or neutral
B= 24 volts output heating mode only
Hope this helps to answer your question, if you need any further help one of us on here can help.

Good luck
Rusty
 
#3 ·
Rusty, pretty good explaination, but I need to correct one thing...I hope you don't mind. There is NO neutral in a 24vac circuit, it is referred to as common, being the coil return to the secondary transformer winding. This winding is sometimes grounded which would make it appear like a 110v circuit, but it does not complete the circuit with the ground like a 110v neutral does. Just a clarification.
 
#4 ·
This winding is sometimes grounded which would make it appear like a 110v circuit, but it does not complete the circuit with the ground like a 110v neutral does. Just a clarification.
Actually, on large RTU 24v transformers, it does. Normally over about 1000va.

"neutral" is a meaningless term, in reality anyhow. Probably not worth fussing over rhetoric, I suppose.
 
#10 ·
Hi Air Pro

Not a problem, the way I see it this sight is for each proffesional on here to be able to help another with a problem. Just to clarify my use of the word, Md was right neutral is kind of a relevant term used loosely. However in this case I was referring to it as a non voltage carring line in the open state. However it has the potential to carry voltage when hooked into series with a device, thermostat, relay, etc. This was why I put that in the post. I have even heard it called a return line. Not exactly sure that thats a better term for it, just wanted to make sure he had the possible needed information. Besides, the day we quit teaching one another, boy is this world going to be in trouble. Who will take care of their comfort?

Rusty
 
#12 ·
NCSTEVE,
Be careful where you hook up the common wire. Some of the older Trane stats use the "B" terminal for common, typically these will not have a "C" terminal. Some of their stats also use "X" for common. If you hook up to the "B" terminal on some stats when you turn the mode switch to heat you now have a dead short, and if you do not have an inline fuse you will let the smoke out of the transformer and we all know how hard it is to get it all the smoke back into the transformer :laughing: . If you do not have the install litature let me know the model # and I can email one to you.

John
 
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