Motor on my RUUD gas upflow 90% furnace (~10 years old) just fried itself. Grainger has a motor that is equivalent in all ways except one - the full load amps (FLA) rating. The existing motor is a GE 115VAC 1/2hp 1050 RPM model 5KCP39KG R911. The Grainger motor has a FLA rating of 7.8A, and details are available here:

http://www.grainger.com/Grainger/DAYTON-Direct-Drive-Blower-Motor-3LU83?Pid=search

I understand that a motor will only pull FLA under maximum load, but I'm concerned that if the motor ever pulls significantly more than 6.3A that it will cause problems for (and potentially fry) the integrated furnace control board. The last thing I want to do is replace the blower motor and fry the (expensive!) control.

If the Grainger motor is not an acceptable replacement, advice on where to find a replacement would be appreciated. It appears that this GE motor is no longer available. Thanks!

The FLA will vary slightly from motor to motor (within 1- 2 amps) it sounds like you have researched and found the proper voltage,RPM, motor that you need. You should be fine. Make sure you get a new run capacitor with your motor to ensure it is the proper size. I'm assuming your are getting a universal bi-directional motor so make sure you wire it up for the proper rotation for your application (clockwise or counter clockwise)