So short and open circuits, it's important to know the difference. Anybody feel like telling me the difference between a short and an open circuit. Anyone sure go ahead. Sam okay and open is no path so the way I always say it, which is, I don't know if anybody likes this or not, it doesn't seem to go over very well, but it short is when something is happening that should not be happening and an open.

If something is not happening, that should be happening say that again, an open is something is not happening. That should be happening. You walk in you flip on the light, switch and light soon come on right breakers on lights, aren't on that's an open! Something happening that should not be happening would be. You turn on your thermostat for cooling and the heat comes on.

Also, that's a short something's happening that should not be happening or you flip the switch on in the breaker trips. That's something happening that should not be happening. That's a short most cases electricians when they talk about shorts, they're, talking about an undesigned, no-load path or undesigned low resistance path. So the obvious one would be.

You know like the chair we drew before here or any anything that connects these two halves. That's an obvious! Traditional short, it's a path that has no load in it or low resistance. That's a short, but we also know that there's shorts, that we see on the load side of switches, thermostats a switch right. You guys all know that it's primarily a switch.

It has a load in it too, as well for the microprocessor. That's what you have power in common, it's because it's doing some work in there, but primarily it's a switch. It's there to open and close switches, make and break paths right and so the line side of a thermostat. What terminal is the line side of a thermostat? This is a pretty old-school thermostat.

What terminal is the line side of a thermostat, hmm r-right? Our is the line side that is, the feeding power into the thermostat, I'm too weak to get that open. So this is our our terminal right here. What are some of the load sides of the thermostat y.g w/o a lot of different load sides, because there's this that's going out to the loads right? What happens if two of those load sides touch each other? Let's say Y touches W. What happens it's a short, but does it blow a fuse if Y touches W? No, doesn't it doesn't blow a fuse? It doesn't create high current.

It's not a no load path. It's an undesigned path between two load side circuits, so that results in the heat running with the air right and the air running with the heat, both you're mixing load side circuits. We also call that a short there's, nothing else to call it. I don't know what else to call it, so we call it a short right.

So it's something that's happening that shouldn't be happening, heats running with the air. The fuse is blowing the breakers tripping. Those are all shorts and open is there is no path at all. So, walk up to a motor power is applied to of say here we got 240 volts applied to the motor and it's not running is that an open or a short, that's an open, walk up to a condenser breakers trip reset the breaker breaker trips again.

Is that a shorter and open that's a short right now, that's not how you should do that. You shouldn't just walk up and reset breakers, but oh it's just as an aside. What should you do if you walk up to a system that has a trip raker, you know I. I know that that's what most of you do, but that's not what you should do.

You should do a visual, a full visual inspection of that piece of equipment before you reset that breaker, because let's say that it then it arced out. This hat has happened where it's a a high voltage line, that's arced out against the discharge line, but it hasn't blown through it. Yet, and now you go and you reset it and it finally does the job and blows through the discharge line, the losses, all the charge. That's happened, it's rare, but it's happened or if it's inside the electrical cabinet and it's a rat's nest and a wire came loose and now every time you reset that breaker you're causing a big arc flash.

Not only is it not safe for you, it's not good. For the equipment, so whenever you find a trip, breaker or a blown fuse, you should always do a visual inspection before you just reset always follow me. Everybody bye! You guys bye what I'm selling here catch, what I'm catch, what I'm pitching you know, you're, not buying it use reset it yeah! Okay, all right, so knowing that Emerson is short and open is a really key language. It's a really key, a descriptor when you're talking to a senior technician, you're talking to somebody to say I have a short or I have a shorted compressor.

A shortage, compressor and an open compressor are different, which is why one of my questions on my my application for new technicians is: you have a shortage compressor when you walk up to the system, what will be, what will have happened and a lot of them will Say the unit won't run well. That may be technically correct, but the unit won't run because the breakers tripped, if you have a shortage compressor when you walk up to the equipment, the breaker is going to be tripped. If you have a compressor, that's out on thermal overload and you walk up to the unit, what will happen just the fans gon na run right right, the breaker is not gon na be tripped. Thermal overload does not result in a breaker trip, so you know - and we see guys do this from time to time you walk up and there they got a hose on the compressor.

What are you doing? Well, Britt. You know, I think it's shorted I'm trying to reset it. It's like no open overload results in an open circuit, compressor, not running, but not resulting in a breaker tripping. A shorted compressor won't trip the breaker all the time.

Okay describe that one. Okay, all right very sneaky, yeah good point good point, because, because the ground that safety circuit is the ground fault path, so that's why we connect to ground is to create a path back to the panel. So that way, when there is a short, we create a ground fault, there's a path and that ground fault trips, a breaker good point, though, can be, can be. You know the breakers being.

No good are like fuses blowing. For no reason it doesn't happen. Yes, it's exceptionally rare, though now usually when a breaker does fail, and we see this a lot in in pool heaters for property managers. We see this all the time and the reason is is because they use that breaker as a disconnect they're constantly turning it on and off and over time the breaker becomes open, it's not making contact and it will usually stop making contact only on one leg, which Gets back to this whole confusing situation where technicians call us they they're looking their breaker here, we're gon na make this a.

I don't know what kind of breaker this would be. I will just make it a contactor and what it's a Brian breaker, yeah they'll, take a contactor and they gets got l1 and l2 going into it. L1 l2 right and they'll go 500 wente volts they're. Actually, no sorry, I'm doing this wrong because that wouldn't single pool breaker I got hundred twenty volts there.

I got a hundred twenty volts there. I got it breakers good and then we, what do we always say Jesse check for 240. Do you have 230 volts there? No, I don't have tuna pretty welts there, okay, the reason why you're reading 120 volts is because it's one leg of power, that's feeding through the compressor in the load and then coming back the other side. That doesn't mean that you have power.

That doesn't mean that you have 240 volts applied. You've always got to check and generally you're doing it at the breaker. They'll take one side to ground other side to ground. I'm gon na read 120 volts on both side and think that the breaker is good when in fact, you have to read 240 volts coming into the breaker 240 volts coming out of the breaker.

That's how you know you have a good breaker. If you have 200 volts going into the breaker, and you don't have 240 volts coming out of the breaker, you don't have a good breaker.