Last year my home's central air condenser fan motor stopped working. When I noticed the house wasn't cooling down I went outside to investigate and found there was a humming sound coming from the unit, but the fan wasn't turning. After researching the problem online, I found the capacitor may be bad and causing the problem. The capacitor wasn't blown, but I replaced it anyways. The problem still existed; Fan won't spin and a humming sound is coming from the unit. So, I inferred that the motor must be bad. Yesterday I unbolted the fan from the unit to try and spin the blades by hand. To my surprise, it spun. It spun 3 to 5 rotations with a medium amount of force (the same force it would take to bounce a basketball 8 feet in the air). I expected the motor to be stuck and not spin at all, so now I'm second guessing myself. My question is: How freely should it spin? I've read in numerous places that the blade should spin "freely", but I'm not sure what that means. Should it spin around 50 times with a medium amount of force?

If I was holding it up in the air, should a 15mph breeze spin the blades like a pinwheel? Or is the 3-5 rotations freely? If you replaced the start capacitor, and you are getting proper voltage to the fan motor than the only thing left is to replace the fan motor. If the fan turns at all without forcing, it should spin when powered up. If the fan turns freely or not is not a definitive indication that is good or bad. It should spin freely... I looked at neighbor's condenser fan and they all spin freely with very slight force. However how a motor spins isn't necessarily indicator of whether it works or not. A coil could have shorted or insulation burnt. You can test this by taking an ohmmeter, one lead to the motor leads, and the other to the case. If there's continuity between the leads and the motor casing, it's bad (and in fact sometimes it should blow breakers too). You can also read the resistance of the motor leads, if it's too low then there's a short between the windings.

Basically a good fan should spin at least half a revolution with the amount of force it takes to lift a sheet of paper. I'm far from being a HVAC person, but I do like to figure things out on my own. I had the same thing happen and before you order a $300 part, all I did was take it apart and clean it really well. I used graphite lubricant on the blades and 3-in-1 on the shaft of the motor and guess what?!! It puuuurs now ;) if u change the capacitor and does not work turn the power on use a screwdriver and try turning the fan you will notice motor making a buzzing sound and hard to turn just replace motor.how to replace a capacitor on an ac unitI had the same problem and that took care of it.20 ton cooling unitTwo more things your motor may have three wire black brown and orange today motor have five wire instruction come with it connect the two extra wire together with a wire nut and wrap it with some electrical tape.water leak from ac unit

Last i recommend u change your contact switch because when your motor start going bad it spark more and more as the motor life coming to an end.I hope this was helpful good luck.Browse other questions tagged hvac fans or ask your own question.We all attach a utility with every object we buy. One of the basic things we expect from an air conditioner is that it should give good cooling. Faster or slower, but it should cool well in order to get the temperatures down to comfortable levels. When it does not do so, we do not derive utility from the product and want to replace it. But these questions arise in several minds: “Why is it that my AC which was cooling well till a few months back is not cooling well now?”, “I bought a new AC but why is it not cooling well?” or “This AC used to work really well a few years back but is ineffective now”. There can be several reasons for the same, some of which can be technical faults as well. But here we would try to explain some of the reasons, which may not be fault in the AC itself.

One of the common complaints from people living in northern part of India during peak summers is that the AC is not cooling effectively or the compressor is not working. Unknowingly while installation of the AC, people do not realize that the outdoor unit (in case of split AC) or the outer part of the AC (in case of window AC) is directly facing the sun. All ACs have an optimum operating temperature (ambient or surrounding temperature) at which they can work most effectively. If the temperature increases beyond the optimum temperature, the efficiency of the air conditioner goes down and it can also reach a stage where the compressor stops working completely. At lower efficiency, it can also consume more electricity than that mentioned on the BEE label. Typically numbers on BEE label are in test conditions.: This happens because the job of AC is to take heat from inside the room and throw it outside. But if the heat outside itself is quite high, then it is not able to do its job properly.

Air Conditioners are designed to work at a certain optimum ambient temperature and beyond that they stop working. How much is optimum temperature? For most ACs it is about 46-48 degrees. Beyond which they can become less effective or may even stop working. These days some brands have models that can handle up to 52 or 54 degrees. Solution: The best thing that you can do is to avoid installing an AC in such a way that it faces direct sun or is in a place where there is lot of heat. And it is not necessary that heat can happen only in a city where the temperature goes high. It can happen anywhere if the ODU is in closed hot place. Also one can even use an AC with optimum temperature of 46 in a place where the temperature goes high. It would just need a place where the surrounding temperature is low. This can be achieved by placing plants around the AC or by pouring some water on it occasionally (although it can be cumbersome), or by any other creative idea. One of the common mistakes people make is that they buy AC just based on their budget and not based on the requirement of the room.

A small AC in a huge room will always find hard to cool the room in peak summers. Thumb rules for sizing ACs do not work always and one has to look at several parameters while sizing air conditioners. Certain cities are hotter in summers, which mean they require more cooling for the same size room as compared to cities where temperature is less. Some cities are more humid than hot and so the cooling requirement is less, but what is more important is humidity removal. Thumb rule of 1 ton for 100 sq ft (most commonly used thumb rule) does not work always and one should make sure that proper sizing is done before buying AC so that there are no regrets after the purchase. Yes aging not only impacts humans, but appliances too. With time efficiencies of most appliances come down. Cooling of an air conditioner reduces with time, or I must say with time it takes more electricity to give the same amount of cooling. As per ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers) an air conditioner reduces its efficiency by 7% in the first year, 5% in the second year, 2% every year in the following years, and this reduction peaks somewhere between 20-30% depending on how well the air conditioner is built.