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AC trouble? How To Troubleshoot An AC Trouble On The DSC NEO

Hey, guys. Hayden here again from Alarm System Store. And today we're going to be talking about a common trouble that most people will see on their alarm system. And that is the AC trouble. And AC trouble is basically an indicator that your system is not receiving the proper input voltage. So anytime you have an alarm system, you will have basically a transformer plugged into a wall. And that is going to be where your input voltage comes from. And so this is plugged into an outlet. And then you have a wire running from the transformer into the panel. And now most panels of their hardwired systems will have a setup like this where you have two AC terminals on the left side of the board. And those are where your input voltage goes in. Now this particular system is a DSC neo. So I'm going to be showing the troubles showing up on the DSC neo. But this applies to pretty much any alarm system out there. So if your system happens to have an AC trouble it may show it a bit differently. It might not show AC trouble, it might have a different name entirely, but it should indicate some sort of power outage.

So essentially, with this transformer here on the DSC neo, what we use is the PTC1640 transformer, and that is a 16.5V, 40 volt amp transformer. And what this does is it transforms the power from 110V out of your outlet, down to about 16.5 or slightly higher volts. And that goes into your panel. Now, the panel from there actually converts it to DC power. And that's what all of your actual alarm system devices use, like your keypads, your emotions, so on and so forth. But this AC input voltage is what powers the system up, and it is also what keeps your battery charged. And that just provides power to the whole system. So right now, as you can see, I got the transformer unplugged. My system is running solely on battery power right now, and that was the idea behind the backup battery. It just allows your system to keep running for a period of time after you have lost your AC voltage. Now, generally that's only going to apply the light power outages and things like that where it's kind of temporary. but in some cases you may actually run into a problem with your AC transformer or the wire connected to it, or perhaps even the outlet.

So here, in a couple minutes, I'm going to run over how to troubleshoot that. let me show you on the keypad real quick what an AC trouble looks like since I have one. So if you hit your start to menu, that's going to bring up the trouble menu on the DSC neo. Now, other systems will likely have some other method of showing troubles, but on the neo, what you're going to see is press star to view. AC trouble. If we hit star there it's going to say AC troubles system area. And that is because it is talking about the main board of the system. So this transformer is powering the main board which is also known as the system area. Now you will also see other troubles that will show up under that AC trouble section. If you happen to have a power supply for your system, like an HSM 2204 or 2300 on the Neo, there is an extra power supply that just provides additional power for devices on your system, and generally you'll only see those power supplies if you happen to have, like a lot of keypads or a lot of power devices like motions and glass breaks and things like that. but essentially, if you happen to have those, you will also see troubles for those. And what you'll see is you'll see AC trouble HSM 2204 one. I think you can have four of them on the system, so it will actually indicate whether it's the main system, whether it's a power supply, and if it's a power supply, it'll tell you which one as well.

So if you happen to run into an AC trouble, there are a couple things you can do prior to diagnosing the system itself. that might help. First, just make sure that your house has power. That one's pretty quick. Just flip on a light switch. Light comes on, you're good. If not, then your house has an outage and you'll just need to wait for it to subside. And if your house does have power, the next thing to check would be the breaker that controls the outlet that the transformers plugged into. So hit your breaker box, open it up and just double check the breaker that is connected to this outlet and make sure that it is not tripped. Now, if you happen to have power to your home and none of the breakers are tripped, that's when you can start diagnosing the actual system in the transformer itself. So what we're going to use to do that is a voltmeter. Just turn it on real quick. Now, there might be some people out there that do not have a voltmeter, but I highly recommend getting one. They're very cheap. you can usually get them like ten, 15 bucks. they might not be the best in the world, but if you're just checking AC voltage like we are here, it can be very handy.

So what we're going to do first is we're actually going to check at the main board and the two AC terminals that I mentioned earlier. so what we want to do is we want to start at the main board. We want to work our way back to the transformer because it could be a wire issue, could be a transformer issue, or it could be an outlet issue. At this point. So what we're going to do is we're going to take these two leads, and we're going to touch them to the two AC wires that are going into your panel right here. And if you look, we should have around 18.5 volts. Yeah 18.4. Little over 18.4. So that is perfect. actually with this transformer, even though it is a 16.5V transformer, you generally do get about 10% extra power out of the transformer. So it's a 16.5V. We're getting 18V 18 to 18.5. That's perfect. if you happen to see anything less than 18V, then you may have a problem. But if it's still above 16.5, then you should be fine. That particular transformer might not be providing that extra 10% or so that most of them get. If you happen to see less than 16V, though, that is a problem. So now we need to start tracing back to the transformer and figure out where the problem lies. So to check the transformer, all we're going to do is leave it plugged into the outlet. you can use a power strip for this if it's easier for you, but essentially we need to check the two AC terminals that are on this transformer.

So right here you'll see them labeled AC, AC. And then most of them will have a ground. You can ignore the ground if you're working with an alarm system and the ground is for general AC applications that use three wire alarm systems, just use two. So what we're going to do is take those leads and we're going to touch them to the two screws under here that our wires are connected to. Now at this particular point, you don't have to be worried about any getting shocked or anything like that. 18V at this amperage is so low that you won't even notice it. But essentially we just want to make sure that we are getting our 18.5 or so volts out of the transformer itself. So in this scenario where you have voltage at the transformer, but you do not have voltage at the panel, that 18.5V, that means you have a wire problem. So what you need to do is you need to replace the 18 gauge, two conductor wire that is connected to the transformer and the system. That should fix the issue, and you should be good to go from there. However, if your transformer is not showing above 16V, then you could have a transformer issue or potentially an outlet issue.

One thing I've noticed is if these transformers get shorted, essentially they slowly lose their ability to transform power. So if it gets shorted, it's not going to immediately show that zero voltage, it will show voltage on it. And if you watch it, it will slowly decrease over time. If it is slowly dropping like that, most likely the transformer shorted. So in that scenario, I would recommend replacing the transformer and the wire to make sure that the short doesn't happen again. Outside of that though, that's pretty much all there is to AC troubles on an alarm system. Now, like I said, you could have other modules, you could have multiple transformers. each power supply has its own transformer and its own battery. So you'll see troubles related to those, for each unit. So, just one thing to keep in mind is, you know, check the simple stuff first. Make sure that the outlet that you're working with has power. Plug a lamp into it, flip the light switch. if it does have power, but you're still running into issues, you can run through the diagnostics that I showed you here just a minute ago. And if you happen to need a new transformer, you can get these 1640s on our site without much trouble. I think they're about $17. one thing to keep in mind, though, is not all alarm systems do use that same voltage. So double check the actual rating of your transformer to make sure that it is a 16.5 volt or somewhere in that area, and that is pretty much all there is to the AC trouble.

There's not a whole lot to it. Essentially, you just need to make sure that your system is getting power. Those are the things to check if you're running into AC troubles on your system, though. And that way you can diagnose where the problem lies and fix it accordingly. If you guys are on our YouTube channel, if you don't mind, leave a like and subscribe. We really appreciate it. And if you're on our website, check out the rest of the troubleshooting videos we have there. I've done a whole troubleshooting series on the DSC, neo in particular, and I've done a lot of other videos as far as the installation and, you know, changing out sensors, things like that. We even did a panel swap, I think a couple years ago. But essentially we have lots of information for you guys out there. So if you want to check it out now, this is more aimed at DIYers or people that are just looking to solve problems themselves without having to pay for a truck roll and that whole bit. So hopefully these videos are beneficial to you. And if you happen to want to see a particular type of video or have a particular question, feel free to reach out to us at or if you're on YouTube, leave us a comment and we'll go from there. Other than that, I will catch you guys on the next one.