AC wont blow

Reply

  #1  
Old 07-20-08, 06:44 PM
Member
Thread Starter
Join Date: Jul 2008
Posts: 5
Post AC wont blow

Help
I have a TRANE XE 1100. when the thermostat calls for air, the compressor unit outside kicks on, the big line gets so cold that it gets frost on it, but the air blower on the furnace unit (Trane XE 90) doesn't come on????

The furnace unit under the house has a normal slow blinking light and the fuse on the control board is good.

does anyone have any ideas that may help?

thanks
 
Sponsored Links
  #2  
Old 07-21-08, 07:32 AM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
Please post the full model numbers for these units.

XE1100 and XE90 are just the marketing names, not their actual model numbers. Look for their nameplates.
 
  #3  
Old 07-21-08, 03:54 PM
Member
Thread Starter
Join Date: Jul 2008
Posts: 5
It appears to be Model # TDC 060 C93 6B6
 
  #4  
Old 07-21-08, 05:20 PM
Member
Thread Starter
Join Date: Jul 2008
Posts: 5
AC Blower won't come on

It appears I have a good fuse on the control board on the blower unit (furnace)
28vac at the transformer
28vac at the R & C leads on board at the blower unit
28vac at the R & G leads at the stat
 
  #5  
Old 07-21-08, 05:42 PM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
R and G should read "0" volts when the thermostat is calling for cooling or if you turn the FAN switch of the thermostat from AUTO to ON. There should be 28V between G and C if the module its doing its job of sending 24V to the fan relay (also in the module)
 
  #6  
Old 07-21-08, 06:15 PM
pflor's Avatar
Member
Join Date: Dec 2007
Location: U.S.A.
Posts: 1,127
You should not keep your unit running if the indoor blower won't start. Doing so risks sending liquid refrigerant back to the compressor, something which will kill the compressor in a short period of time.

With the thermostat calling for cooling, you should be able to read 24V (or, as you report, 28V) between terminals Y and C on the module's terminal board (this would indicate that the outdoor unit is getting its juice, and the compressor/outdoor blower would be up and running). You should also be able to read 24V between terminals G and C on the same board (this is how the blower relay, which is soldered on the board gets its juice).

If you indeed read 24V between G and C and the fan is not running, check for 120V being supplied to the blower motor high speed wires. Which ones are these? The black and white wires...the black connects on the module to terminal "Cool-H" and the white to "CIR-N. If you read "0V" instead of 120V, your board is bad (the fan relay on it actually); if you are getting 120V on these and the blower is not running, then you either have a bad fan-capacitor or a bad fan motor.
Check the capacitor, it is mounted on the body of the fan motor (with a clamp) and has two brown wires attached to it.
120V on the above terminals plus a good capacitor would tell of a bad fan motor.
 
  #7  
Old 07-21-08, 07:20 PM
Member
Thread Starter
Join Date: Jul 2008
Posts: 5
Thumbs up

I actually pulled the 120vac breaker to the compressor so it wouldn't come on. Its control board held power, so I figured the air handler wouldn't know the difference.

went back down with it set to call for air with the fan switched on -
Y+C = 26vac
G+C = 26vac
Cool-H + CIR-N = 0vac

So I'm see what your saying since the leads from the X-former have 120vac and then when it comes back out of the board its 0.

thanks a bunch for your help.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes