The condenser fan motor on my "york" unit locked up. I replaced the motor but the new motor stops working after about 20 minutes. The condenser continues to work but obviously overheats because the fan is not working. The only difference between the old motor and the new one is the RPM. The new one is 1075 RPM and the old was 850 RPM. Would that make it stop working?

When replacing a motor,, a new capictor should be bought and used that matches the new motor,, the capictor needed is written on side of the motor,, this would be a seporate capictor just for the fan motot only

As for the speed/rpm`s they should match,but faster rpm`s is better than to slow