Bad Air Conditioner Blower Motor or Condenser Fan Motor
Labor (troubleshooting and repair of the air conditioner system) time (approximate): 1 1/2 to 3 hours depending on unit location and part availability
This is common in the summer. High heat and constant use causes old (and some new) air conditioner blower motors or condenser fan motors to burn up. There are several different types of air conditioner motors and when dealing with anything electrical the best replacement is an exact replacement. There is a contradiction to that phrase. If you have a shaded pole air conditioner blower motor in your air handler I recommend that it be replaced with a PSC motor. If you don’t know what that terminology means, the air conditioner technician should know. PSC motors are far more efficient for air handler blower motor applications than shaded pole motors. Shaded pole air conditioner motors are a rare find (at least for me) but when they are found in blowers they should be replaced with PSC motors. Additionally, when replacing any PSC motor I recommend replacing the capacitor.
If the air-handling unit is difficult to access it will take the air conditioner technician more time to change the motor. Some motors can be carried on the truck but most have to be picked up from an HVAC parts supplier. There are companies with parts runners. Once the HVAC tech diagnoses the problem they call the parts runner. Sometimes, by the time the technician has the old motor pulled the parts runner has the new motor delivered. If your unit is equipped with a double shafted motor expect to pay up to $300.00 or more for a new motor. These double shafted motors are rare in residential units but they do exist. Out of about a hundred motors in 2001 I only had one that was double shafted. Another medium ticket item for replacing is the ECM blower motor which variable speed and can be found on most high SEER units. Variable speed motors are more expensive than standard blower fan motors or condenser fan motors but they are more efficient than conventional PSC motors and have better although more sophisticated control. If you have a variable speed motor that is bad it is important to replace the motor with an exact replacement and depending on the OEM of the equipment will depend on the cost of the part that needs to be replaced. Sometimes an after-market variable speed motor can be used however most brands have proprietary connections for the electrical so an exact replacement is needed for repair when a bad variable speed fan motor is found.
It is important with a condenser fan motor that the fan motor be protected from moisture. Most condenser fan motors have a closed motor housing to keep moisture from getting inot the motor or windings of the condenser fan motor. Again, as with the air handler blower motor mentioned above when the condenser fan motor is replace the motor run capacitor for the motor should also be replaced. I replace the motor run capacitor even if it tests good. The reason for this is because when some electrical components get hot they breakdown or have a history of breaking down if they are defective. When motor run capacitors are tested they are tested cold. It is nearly impossible to test the motor run capacitor when it is hot so I replace it. It is better to be safe than sorry. Variable speed condenser motors or variable speed blower motors do not use capacitors as conventional PSC motors use so there is no need to check capacitors in systems that have variable speed blower motors or variable speed condenser fan motors.
Typically the air conditioner blower motor will be replaced with a stock blower motor from the HVAC supply store or from a stock blower motor on the truck. The blower motor may not be the same brand but it is important, and the HVAC technician should understand this, that the blower motor be matched for amp draw, voltage, RPM, diameter of motor for remounting in existing bracket, and motor direction whether it be clockwise or counter-clockwise. There are blower motors which are reversible with a simple wiring change and the bracket which is in the existing unit may not be able to be reused. Sometimes it also necessary to change the blower wheel also if this wheel is damage in any way or out of balance. The HVAC technician will be able to recognize all these things and offer quick efficient solutions. Parts are also the problem for the typical average consumer as most HVAC supply houses or even OEM stores do not sell to the general public. There are many reasons for this but it is partly to encourage competent repairs by a skilled technician when the system fails.