Why can an AC contactor stop cooling?

we just want to be able to see in there take a look at that if it looks pitted looks rough we don't want that that's what we're seeing on this one over here is that we've got quite a bit of of buildup it's not smooth it's rough it looks like sandpaper we don't want that we want a nice smooth patch look at this contactor you don't have any carbon any kind of soot build up these contact points are are very smooth and uniform what the contactor should look like

Three red flags we spotted on this AC system in Norman, Oklahoma. First, the outdoor coil was extremely dirty, so we gave it a deep cleaning to restore air flow. Second, the contacttor was in rough shape, so we replaced it today to keep the system running. And third, the condenser fan motor showed signs of wear, so we recommended replacing it soon. With the coil cleaned and contacttor replaced, this AC is ready to keep the home cool for summer. And shout out to our technician, Joseph, for doing great work. [Music]

if you check right right behind my finger there you can see some severe pitting every time this air conditioner gets a signal to come on that switch closes and you get a lot of pitting from these contacts getting hot slam and shut opening up over time and this is one of the more common parts that we replace it's usually a 5 seven year part and I would have no idea whether this one has ever been replaced or not I'm definitely going to talk to the homeowner about getting a price to replace this system just to have that price to compare side by side with repair prices because a lot of things that are currently underperforming a lot of things are going to be on their way out soon still haven't checked the amperage on that fan motor which I'm very curious about couple other things I've just noticed here this low voltage wire here you got good connections within the cabinet but you follow it back this has been spliced onto it some point um follow it back here you can see where we had the two wire you follow it back up here you can see our casing is completely split open exposed wire right there and then going through the brick young Rose

When you hear your AC making noises like this, it's usually a bad sign. In this Oklahoma City home, uh the contactctor was chattering and blowing fuses. Uh we replace the fuses and the contacttor, checked the pressures. Now the system is cooling like it should. Shout out to Philip for taking care of this customer. [Music]

This is a contactor. These are a very important part. What it actually does is it takes a 24-V signal from your inside and then it closes a set of contacts on here to actually send power through to power your unit. Typically, what happens with these is they start to get pitted through over-amping and other factors. Typically, these will last anywhere from 7 to 10 years. Cost to replace these is usually anywhere from $200 and up. And that's what I tell people about this part.

some easy ways to check that is while the actual unit is calling and you have power to this and I do stress that you be very careful on this because you are with live power but when this contactor is pulling in you can simply take your voltmeter and you can actually check between the points and see what your what we call a voltage drop is you should not be getting any voltage when you read between this point and this point another common thing is in these points there's a good chance you can get ants so if you see any kind of ants buil up around your unit definitely would do something about spraying that to keep those out of there because they will get in that contactor and even if you clean out these points there's something with them that it will not make contact

You hear a click and nothing happens. Your thermostat clicks on, the indoor fan runs, and the box out- outside just sits there like the lazy tyrant it is, not giving you air conditioning. Listen, a lot of times you hear a hard click, then nothing. The old contactor is trying to pull in and the points are burnt out. Maybe it's not connecting properly. Replacing the contactor is about $285. It is a common fix, not a new system speech. It can also be a breaker or a flow switch. So we check before we guess. I'm Colby Yarbrough with Yarbrough Sun, Heat, Air, and Plumbing. What sound is your condenser making?

Your system is down if that contactor fails. The number two most recommended repair that we do during spring maintenance is the contactor. So, what we're looking for on that is is there pitting on the contactor? Uh what's the ohm rating across the coil of the contactor? Are we getting any voltage drop or anything across the the points of the contactor? So, you know, we're looking for all of that stuff. Any of those could cause your contactor to fail. Your pros. >> [singing] [music]

So pitting happens because whenever we're sending electricity to this simple 24 volts comes, it magnetizes this right here and pulls in on this contact. So when that happens, it just slaps down. What it actually happens is sometimes this slaps down and when it comes to AC current, we're looking at a wave. And so with that wave, that sine wave, if you're at the top of the wave, that's when you have the fullest power. You're having a problem where you're going to have an arc. And so that arc causes pity. [Music]

one thing I would suggest is an actual sh switch they actually last a lot longer um their contacts are actually enclosed to where ants and all that can't get to them a lot of guys call these ant proof contactors but they uh really have a great a great system um but they are a little bit more complicated to replace

This is a contactor. Very common part to see fail. Uh usually because of pitting or you have little ants crawling around. So with that being said, cost for installation out the door would be about 291 for this contacttor. And that includes labor and the part. [Music]

this is a contactor now we usually see contactors in situations where we want to use a higher amp draw on something so this is actually used for the heat strips and just like a relay we're going to have a coil that's 24 volts on this one that's going to power this and suck in those contactors just like a relay you can actually have these points get pitted and that's usually what the common problem is with them anytime you're bringing in high voltage and you're slapping across there it's going to cause distortion on that surface of that point and that's going to cause it to break down typical life expectances these is usually about 5 years they'll start getting pitted up and really need to makeing sure that you're checking them one thing we run into a problem with a lot on these is you'll get those points pitted up and so it's not making a good contact and you're actually causing these wires to get hotter than what they need so one thing you'll usually see is a wire that'll be burnt off and that's never fun to to deal with and causes other problems you know you definitely want to have them checked out regularly to make sure that there's no issues with them regular maintenance is not going to save the contactor but it's going to save you a lot of headaches of damaging other controls in your system by not having enough power go where it needs so we want to make sure anytime that this is damaged that we get it replaced the price on this is going to be somewhere around $275

the other point that I always like to make is we do have 24 volts coming to this so really this is just a switch we have a 24v wires that come and actually call for this to come on it pulls in this contact and that allows the power to go through to turn on your fan and your compressor if this is not pulled in but you have power always go and you can take a voltmeter and you can check between these two points or the actual coil side the 24 volt side and you should have anywhere from 25 to 20 7 volts if you're getting that that contactor should be pulled in if that's not coming in there's a good chance there's a problem with the actual coil and that this would need to be replaced

these are actually the inlet wires that come from your disconnect we actually call these the line voltage coming in and then these wires on the top are actually your load voltage so you want to make sure that when you're wiring up everything you have all this wired up the way you were and you want to make sure that on each leg you're getting the correct wires so if you ever want to replace these I always suggest pull these screws out and then gets your new contactor and actually kind of pull this back line up those holes if you can and put your screws back in and then at this point we can go wire for wire right onto the new contactor

Today we're going to look at a contactor. We're going to look at what are common problems with the contactor, how to diagnose it, and how to replace it. So, after you remove that panel, we're going to be looking at your contactor right here. Now, some common things to look for on the contactor is pitting on these actual points. That's a common place for them to fail. It doesn't make the actual contact that it needs to. So, we're not passing electricity through.