In this video we're going to talk about the replacement of condensing fan, motors or condenser fan motors some of the best practices here now. The first thing is not to accidentally misdiagnose it. You have to make sure that the motor is actually failed. Sometimes they fail shorted.

The windings fail open, maybe the bearings fail, bearing failure and lock up is probably one of the most common types of failures or maybe they're running noisy, but always make sure you know exactly what's wrong with the motor before you replace it, because there are many other Things that can cause the motor not to run in defrost the condensing fan motor will shut off. If it's a heat pump system also, you could have maybe a wiring problem or a capacitor. That's failed, so there's many different things that can cause it to fail. But if you know that the motor is failed, then you need to make sure first off that you have the right motor to replace it.

Generally speaking, you want to make sure that you match up rpm for sure, and then you also want to look at horsepower. Some people will look at amperage. Instead, those both kind of fall into the same category horsepower and amperage. They both relate to the power at a given voltage.

You want to make sure that it is the proper voltage range for the unit that you're working on in most of the residential and light commercial applications. It's going to be single phase 208 230 volt motors. You want to make sure that the physical size will fit. You want to make sure that the new motor isn't deeper so that it forces the blade down too far past the shroud, because the height that the blade goes in the shroud is actually quite important and something you want to pay close attention to before you pull Out that factory motor, but once you know that you have the right motor you've checked the specifications.

You know that it is a match for what you're going to be doing. You know that it will physically fit in place. Some people will use a slightly higher amperage or slightly higher horsepower motor, and you can do that in some cases do not use a lower rated horsepower or amperage motor in place of the old one. First thing you want to do, then, is make sure you make note of where the wiring went, especially if you're newer and not super comfortable with wiring.

It's a good idea to take photos. You want to make a note of how high the fan blade is located in the shroud before you pull it out. So before we pull, the condenser fan, always pull the disconnect and confirm that it's off with a volt meter, then unwire it take the top off set it upside down in the grass. Also inspect the blade make sure that it's not damaged make sure that it's not bent or any of the rivets are damaged or corrosion, or anything like that, because, if that's the case, you're going to want to go ahead and just get another blade.

But if you are going to reuse the old blade, i pull the set screw all the way out. I use some sort of a penetrating lubricant spray it down really well, and then i attempt to force the blade down towards the motor just a little bit and that exposes a little bit more of the end shaft. I clean it up really good with a sand cloth, maybe some wire brushes, whatever you've got, maybe some emery cloth and get it nice and clean and shiny so that that way, that blade will pull off really smooth in that opposite and opposing direction. Generally speaking, you don't have to do much more than that.

Sometimes it's helpful to put a crescent wrench on the back side, an adjustable wrench on the back side in between the motor and the blade against the flat to kind of hold it and then turn the blade by hand with opposing forces to kind of get it. Spinning a little bit sometimes that rotational force on the shaft will kind of help break it free, and then you can pull that blade up and away from the motor in order to break it free once you get that blade off now, you're going to take the Nuts off the top, sometimes they're acorn nuts. Sometimes they are open back nuts. You want to take those off the top, and then you can go ahead and reinstall.

The new motor now pay close attention to the direction that the wires are pointed. Sometimes it matters, sometimes it doesn't, but you don't want to mount it in a place that the wires are going to be routed in an awkward position. In some cases you are going to need to cut off the studs on the back of the motor after you put those nuts in place, but make sure you put the nuts in place before you cut any of the studs it'll. Make it a lot easier to deal with if you try to put the screws onto cut studs a lot of times, they're not going to thread on generally speaking, most of the systems that we work on have a shaft down orientation.

In that case, you are going to want to cut off the studs at the shaft end. You also want to follow the manufacturer's literature on the removal of the condensate weep holes or condensate drainage ports on the motor, generally speaking, in a blade down orientation. You're going to remove one or two ports down on the bottom side on the shaft side of that motor in order to allow condensate to leak out in a humid market. It's one of the largest reasons why new motors fail is technicians forget to remove those condensate, weep, plugs or drainage ports? Some blades will have more than one set screw, even if you have more than one set screw.

If you only have one flat on the motor shaft, then you only tighten down the one set screw on the one flat. You only want to tighten down set screws on flats on the blade and you don't need to over tighten them. You need to make sure that they're very snug, but you don't want to over, tighten and potentially break them. Next, you want to confirm proper rotation.

This varies and is actually kind of one of those weird things. Generally speaking, what i suggest to newer technicians is install it and leave the rotation wires kind of sticking out the top kind of pull them out. The top install it run. It make sure that they're running in the right direction and then use heat shrink and some tie wires in order to hold up those rotational wires to the top of the unit.

These, the rotational wires, are actually one of the most irritating things that i see with universal motors. A lot of technicians leave them down in the blade or they pull them through the top and then they're kind of a danger, because if a kid were to come along or a pet or something and were to grab those, they could potentially shock themselves. So my preferred method with those rotational wires is to put a piece of heat shrink over them shrink it down once you know, you have the rotation correct and then use tie wires to tie it up on the underside of the condenser top. So that way, they don't rot they're not going to be prone to breakage, like zip ties and they're going to stay there for the long haul in a safe way.

Once that's all done, then you want to properly wire in the motor. You want to make sure to route the wire where the factory wires were. If there's a conduit or if there's a channel, you want to route it in that conduit or channel. You want to bring it into the electrical area and make your connections make them tight and proper and then neaten up all of your wiring.

Now there are both three wire and four wire condenser fan, wiring configurations. Most universal motors can be connected either way. Generally speaking, i prefer uh just replacing your standard dual capacitor with a new one, because then the customer gets a new compressor capacitor and a fan capacitor and just wiring up a three wire and cutting and capping your brown wire with the white stripe. But if you want, you can take your brown wire and your brown wire with the white white stripe and connect it to its own capacitor, completely independent.

Some people like that for its simplicity. That is not my preferred method. Once you get all said and done, and you make sure that nothing's hitting anything that the fan blade spins freely, that everything is wired properly, that it's properly positioned in the shroud that your wheat ports are removed, that it's mounted and fastened properly to the top. All that's done, then.

You can run test the unit. At that point, you check your voltage at the load side of your contactor. So so you turn the system on check. Your voltage make sure that the applied voltage is within the proper range.

Generally, it's going to be make sure you don't have too much voltage drop next check your amperage, your current on your common wire, which is generally going to be your black wire, going to your condensing fan motor to make sure that it is operating in range. But beware: a lot of meters don't have great resolution, especially if it is a low horsepower motor so make sure that you know your meter very well and make sure that your measurement is being taken far enough away from other wires, like your compressor wires, for example, That it isn't picking up inductive interference that can result in a false high current reading. I see a lot of people think that their brand new fan motor is over amping when really it's just that their ammeter is picking up some interference elsewhere or it's just reading. A little bit high but again make sure that your motor was a match for the original motor that was pulled out, especially with rpm and voltage.

Otherwise, you could certainly have a motor or brand new motor that would measure an incorrect current if you put the wrong type of motor in most commonly. I see folks put in a 1075 rpm motor to replace an 825 and you will certainly see an over current condition in those applications. So that's it make sure you have no vibrations make sure you have no noises, make sure the current's in range and once you've done that and everything's wired safely and your direction reversal wires are safely uh fastened and safely insulated so that nobody's going to get into Them and they're not going to fall into the blade, then you're good to go. That's how you replace a condensing fan motor on a typical residential split system.

That's what we've showed you here. So hopefully you found that helpful, we'll catch you on the next video thanks for watching our video, if you enjoyed it and got something out of it, if you wouldn't mind hitting the thumbs up button to like the video subscribe to the channel and click, the notifications Bell to be notified when new videos come out. Hvac school is far more than a youtube channel. You can find out more by going to hvacrschool.com, which is our website and hub for all of our content, including tech tips, videos, podcasts and so much more.

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