I ran across a Carrier Model 30RBB13064-5-7-3 today...had 2 condenser fans with the center hubs split in half, spinning wildly and generally making enough noise to make you want run for cover. These fan assemblies are made of plastic, and bolt on to the the motor shaft. They have keyways, but no setscrews. We just took this chiller under contract recently, not much service info left from previous service provider, other than a note that a fan/motor had been replaced 5-2-11 for the same reason. I won't give the exact price for two motors/blades we're getting hit with, but I will describe it generally as a mortgage payment. With a car payment to boot.
Anyway-has anyone run across problems on this model-or with other units with the same type of blade assembly? I'd be thinking loose mounts causing wobble and stress-only everything is tight. Likewise, the bolts securing the blades to the shafts were tight. Also no indication of short cycling.