Another Trane blower issue

[Mr2gud2u]

I'm having issue with my blower. The motor will not turn during high or low speed. It makes no sound at all doesnt hum or sound like its even trying to start. The led flashes slowly indicating a normal state. I was planning on replacing the starter cap tomorrow. I need to run to work to grab a multimeter, maybe a current clamp, and some tools. I fix medical equipment and its rare to see an electric motor just fail with no warning. I know enough to be dangerous but I am NO HVAC guy. Does anyone know where I should start looking after checking for 24V and that 5amp fuse? I have a model XE90 Thanks for the help.

 

[paul52446m]

I'm having issue with my blower. The motor will not turn during high or low speed. It makes no sound at all doesnt hum or sound like its even trying to start. The led flashes slowly indicating a normal state. I was planning on replacing the starter cap tomorrow. I need to run to work to grab a multimeter, maybe a current clamp, and some tools. I fix medical equipment and its rare to see an electric motor just fail with no warning. I know enough to be dangerous but I am NO HVAC guy. Does anyone know where I should start looking after checking for 24V and that 5amp fuse? I have a model XE90 Thanks for the help.

Does your heat come on? If it does then check for 120 volt power on the blower wires on your electronic board. If the starter cap was bad usually the motor will hum sounds like you are not getting any 120 volt to the blower. If your furnace does not run at all than check your main fuse, switch on the side of furnace, and the small plug in fuse in the electronic board. The door switch on the blower compartment has to be made also. Paul

 

[Mr2gud2u]

My pilot light does kick on. My exhaust fan also kicks on I have 120 on the control board. The panel interlock works like it should. Right now I'm trying to measure 120vac to the actual blower. I'm using the lead marked HEAT-H and PARK. I don't get 120vac on either PARK lead. I don't see any other interlocks on the schematic that need to be made besides the panel switch. I guess I'm looking at a new board. I heard the old board is obsolete. Does the replacement board swap without any need for jumpers or modes?

 

[paul52446m]

My pilot light does kick on. My exhaust fan also kicks on I have 120 on the control board. The panel interlock works like it should. Right now I'm trying to measure 120vac to the actual blower. I'm using the lead marked HEAT-H and PARK. I don't get 120vac on either PARK lead. I don't see any other interlocks on the schematic that need to be made besides the panel switch. I guess I'm looking at a new board. I heard the old board is obsolete. Does the replacement board swap without any need for jumpers or modes?

Check the power from the H post to the common post. there should be power there in a couple min. after the burners come on. If no power, the board is bad. If you have power then the board is good and your problem is in the blower ot start cap.. Paul

 

[thermalmedics]

If you are getting functionality with the other elements of the system. Exhaust motor, T-stat operation etc then I would be looking at the blower motor and run capacitor.

After disconnecting power to the blower motor (pulling plug if 120v or disconnect switch) does the blower motor shaft (ie squrirrel cage fan move or is it seized up?) True, usually a hum will tell you it is seized up and a bad run cap will just not make it start (no hum and free wheeling shaft).

Run capacitors are cheap to replace just match the MFD (microfarad) rating on the side of it. BEFORE touching it you must discharge the old run cap.
1. disconnect power (triple check that)
2. take an insulated screwdriver and holding the insulated handle touch both ends of the terminals of the capacitor.
3. match the new capacitor in mfd rating and reconnect terminals.

TM