So I have a TempStar model NNE050B12G1 furnance that seems to have a blower/capacitor failure. I was having an electrician replace a couple of breakers and when we turned the power back on the blower fan would not kick on while in auto ac or manual fan modes. At first I thought it maybe a breaker issue, so I tracked down the breaker and verified it was properly seated and the wire was secure. At this point I had the furnace open and verified I had power into and out of a screw type fuse. I then traced the power to the door switch and when pressed the power was observed going to the circut board. When the blower was activated it made a humming sound and then power coming into the screw type fuse box dropped out. The panel breaker was not tripped. I reset it anyways and had power back to the screw in fuse holder. I had a new spare panel breaker and installed it and the problem continued. I then moved the breaker over one spot to make sure there was not a bad spot on the panel bar and still had the same issue. At that point I moved onto the unit itself. I opened it up and checked all the wires and connections on the circut panel. Nothing was bulging or had any other obvious signs of failure. I pulled the blower unit out and verified that the fan spun easily. I cleaned off the blower unit and it was still pretty clean since I had cleaned it the previous summer. I replaced the screw in fuse and reinserted the blower unit. Once reinstalled I again verified I had power all the way to the circut board. I attempted to run the blower and again it hummed, but would not turn on. It did however hum longer then previous before the power dropped off. Again reset the panel breaker, even though it was not tripped. Spun fan and activated motor. Still had the hum and did not increase the fan speed or even keep it spinning.
For back ground last year I had a new AC unit and evaporator installed. The system has worked marginally well, and the contractor that did the install claims the lack of performance is due to a cheap undersized blower. We had some problems with icing over earlier this year, but I do not know if it was due to the blower fan or a wife that wants to live in a meat locker.
Sorry if I wrote too much, trying to confirm that it sounds like a bad blower/capicator before I pull the trigger and dump a few hundred on a margnal system.
Thanks for any help or suggestions.