Art wrote:

I have 3 central carrier hvac systems for my house. On the outside
condenser for one of them the fan has gotten quite noisy. In fact it
was initially frozen in the beginning of the season. I got it going
again. The fans motors are mounted upside down in the top of the unit
so you can't see whether there is a spot for oil without taking the
top grill off. I figured I would ask to see whether these fans take
oil before I take it apart. And before anyone asks me about
maintenence..... they were all checked out last year by a reputable
HVAC company but if they take oil apparently the guy didn't bother
lubricating them.

I had a noisy fan on my AC unit several years ago and oiled it myself.
I didn't see any places to put oil in so I took the blade off and
dripped oil down the motor shaft and let it seep in for a few hours.
Neven made any more screeching noises.