View Full Version : AC does not work
colepea
Aug 8, 2010, 09:13 AM
My A/C does not work. I have checked the breakers and the thermostat and I have not seen anything out of the ordinary. The fan does not spin but there is some air coming out of the vent. Now I am lost andnot sure what to look for if I open the A/C unit outside.
NorthernHeat
Aug 8, 2010, 11:10 AM
Does the outside unit come on?
colepea
Aug 8, 2010, 11:41 AM
No the outside unit does not come on.
Stratmando
Aug 8, 2010, 12:00 PM
Probably should be a Sticky for A/C's.
Many systems have an inside Unit(Air Handler) and the outside unit called a Compressor Unit. They Usually will have separate 240 Volts supplying a Disconnect/Switch for each unit.
On these, the inside unit will have a 240 to 24 volt transformer that goes to thermostat then to relays or contactors for Blower, Heat strip, and Compressor.
When set to cool, power goes from thermostat to compressor and blower relays, and for heat it energizes heat and blower relay.
If thermostat is activating fan or anything, the transformer is good.
I would verify power in and out of breakers, disconnects.
colepea
Aug 8, 2010, 02:55 PM
There is power in and out all the way to the outside unit. I used one of the dohickies contrapsions sold at the Lowe's tof verify current is flowing to all the way to capacitor at the outside unit.
Stratmando
Aug 8, 2010, 03:00 PM
Does the inside fan work?
Do you have 24 volts to outside units contactor coil terminals?
colepea
Aug 8, 2010, 03:15 PM
The fan does not spin and I do have voltage at the coil terminal. I don't know what the voltage is because I respect anything that deals with 240V. Little scared to mess in there with the current flow. Feel a lot comfortable with the power off.
Stratmando
Aug 8, 2010, 05:55 PM
This could be as simple as a bad 240 to 24 volt transformer or fuse,
A Tech might manually override the contactor to see if the Outside compressor/Fan is working.
colepea
Aug 8, 2010, 05:58 PM
How do you go about overiding the contactor?
Stratmando
Aug 8, 2010, 06:11 PM
If someone aware that Electricity can Kill can safely push Contactor closed with a Insulated Stick/screwdriver. But if you don't have 24 volts to contactor coil when set to cool, you have a transformer/thermostat problem, Don't know if you got a reaction out of your thermostat?