The unit is a Nordyne Miller 2.5 Ton condenser unit. When it rains and water gets into the top of the unit wetting the fan motor and blades, the fan immediately gets very noisy, like a diesel motor idling. The noise will continue until the unit dries out.
The original fan motor was an open-frame design with the open portion, and shaft, facing down. Even though the shaft was facing down, I reasoned that water was getting into the motor causing the noise. The replacement Nordyne motor (Part#621911) was a new part number and an enclosed motor, so it seemed logical that Nordyne got wise to the original design being problematic. I replaced the motor. Problem solved? No...
Now I am stumped! I have verified that the noise comes from the fan by pulling the fan power leads and running the unit "fanless" while spraying it down with a hose to simulate rain. No excessive noise. However, as soon as I reconnect the fan, the noise starts up, so it is coming from the fan. Once again, as soon as the unit dries out, it is quiet again. This problem happens if just the fan blade is sprayed, so it is not water loading up in the condenser coil and restricting airflow. It can't be water getting into the new motor because the new motor is totally enclosed and the noise starts immediately when the dry fan is sprayed with a short burst from the garden hose. There wouldn't be enough time for water to find its way into an enclosed motor.
To see a video of the problem, visit http://www.youtube.com/watch?v=x6fd7opXGDg
If you have seen this problem and solved it, please pass along the information. Or, if you have some theories, have at it. Thanks!
The original fan motor was an open-frame design with the open portion, and shaft, facing down. Even though the shaft was facing down, I reasoned that water was getting into the motor causing the noise. The replacement Nordyne motor (Part#621911) was a new part number and an enclosed motor, so it seemed logical that Nordyne got wise to the original design being problematic. I replaced the motor. Problem solved? No...
Now I am stumped! I have verified that the noise comes from the fan by pulling the fan power leads and running the unit "fanless" while spraying it down with a hose to simulate rain. No excessive noise. However, as soon as I reconnect the fan, the noise starts up, so it is coming from the fan. Once again, as soon as the unit dries out, it is quiet again. This problem happens if just the fan blade is sprayed, so it is not water loading up in the condenser coil and restricting airflow. It can't be water getting into the new motor because the new motor is totally enclosed and the noise starts immediately when the dry fan is sprayed with a short burst from the garden hose. There wouldn't be enough time for water to find its way into an enclosed motor.
To see a video of the problem, visit http://www.youtube.com/watch?v=x6fd7opXGDg
If you have seen this problem and solved it, please pass along the information. Or, if you have some theories, have at it. Thanks!
