All right, so defrost is one of those things that gets overlooked a lot on heat pumps, especially testing it, and to be frank, if you live in a market like Florida, you know they don't need to defrost that often so you can get away without testing them, But it really should be part of the standard protocol of maintenance and service making sure that the defrost board is gon na work, properly, testing the sensors and all that so today, Jesse's gon na go over real quickly with you how to do it on a carrier And then Bill's gon na talk to you a little bit more about how to do it on a train because he's our resident train expert here we have our defrost board a couple things to note: the outdoor fan motor hooks up to this relay or defrost, or Your coil sensor, so this is sensing the coil temperature, letting the board know when it needs to go in to defrost. If you trace this back on a carrier system here, the defrost sensor connected to the outdoor coil right here again, if you follow these pink wires back, that's going to be testing the coil temperature periodically once this has become frozen cold enough. It's going to force the system into a defrost when it goes into a defrost. A couple things happen sends 24 volts signal to our reversing valve.

Switching the cycles from heating to cooling. It's going to shut off the outdoor fan motor to allow the outdoor coil to defrost, significantly quicker and, at the same time as it's doing all of that we're going to be sending a 24 volt call on our white wire, which will activate our backup heating or Our auxiliary heat strips to allow the space not to cool down too quickly. Hopefully it's just a neutral. You don't gain anything.

You don't lose anything depending on the kW size of the heat. Strips will be a big factor in that and then here you are going to have a setting. You can set it for 30 minutes of D for us to 60 minutes of defrost or 90 minutes of defrost, depending on your location, we'll probably factor the setting. That's you require.

We are currently on 60 minutes of defrost, so we're gon na put the unit back together. We're gon na force it into a defrost cycle, and you have a speed-up tap over here to speed up the process for testing again. This is on a carrier there's a lot of variables based on the equipment type and the manual and we'll go over some of that as well. Right now we're running in heat mode.

If you want to speed up the defrost testing cycle, you can jump up jump around the speed up again, that's going to speed up the process of an actually testing to see if it needs to go into defrost, it's not actually going to force it into a Defrost again we're working on a carrier system, it's going to be different depending on the brand. That being said, we still want to test it out and defrost to confirm that everything's working properly, our defrost sensor is normally open. So you can't just unplug this and have it go into defrost. You actually need to unplug your defrost sensor and then you're going to need to jumper out your defrost sensor and then you're gon na need to go to the speed up, tap and actually speed up.

The process so right now we have it jumpered out so that it thinks that it needs to go into defrost. Now we're going to actually go to the speed up tabs here and hold them down for the required 12 to 24 seconds based on the settings. This one's on 60 minutes should be about 12 seconds, so now it's in defrost. What happens? Is it switches the reversing valve so now that we're putting all that discharge gas into our outdoor coil, which is going to melt the ice at the same time we're shutting off our outdoor fan motor to prevent any air movement over that outdoor coil? Speeding up the defrost cycle at the same time we're also sending a 24 volt call on our white wire, which is going to force our heat strips on on the outside.

Now, if you want to speed up the defrost process since we're just testing it out, you can hold this down for it's approximately two seconds forces it back out of defrost, reversing valve now, switches back to your heat mode, drops our 24 volt call on here and Re-Engages our fan motor and that defrost process, that's the defrost board, what it does again: here's your fan relay which can drop out the fan motor when it's in defrost alright. So this is the carrier, defrost thermostat and, as you can see, this will close at 30 degrees plus or minus 3 degrees and then open again at 65 degrees plus or minus 5 degrees and so closed or in this case. Jumpered is the indication that the coil is frozen and ready for defrost, so hopefully that was beneficial whenever I'm doing one of these videos, it's amazing. I actually learn stuff, as I'm going through it figuring it out.

Oh you don't do that. You do this little things. I've learned today as well. One last thing I wanted to mention is down here.

If you're checking your discharge, temperature you're, just gon na clamp a temp rope on to what is now your discharge line and heat boat that'll get extremely hot. Usually it's right around 90 to 100 degrees over ambient, so over your outdoor temperature. That's that's also a good indicator. This one was really nice because it had what we were looking for, based on the tonnage and the indoor and outdoor conditions.

What we're looking for on our discharge line and then what we're looking for on our common suction island, so we're just going to go over some differences on the carrier. Equipment that we went over today builds an expert with trained. Essentially, it's been working for 20-plus years with trained equipments and those are pretty inside of now, so we're gon na go over a couple of differences. First question: I have: is defrost board we're going to walk over that process on the carrier equipment how to test it before us out of force it to defrost what differences are there from the carrier to the Train, so training defrost is actually very, very simple.

You have two different sensors here. You have one for the outdoor ambient sensor. It tells what the outdoor ambient is into the board with the resistor and also your defrost, your coil temperature, but, coming from your defrost board, these yellow wires trace back into a little tube inside that they put the little resistor inside there and zip tie, and that Leaves the coil temperature much like the clicks on that's in the carrier system, but it's actually read by resistance. There's three test pins and you just jump the test spin it out.

It's almost immediate, I'm gon na train that it'll go into defrost depending on how cold it is outside or how chlorine is outside. You will depend on how long it's in defrost training will actually stop the defrost cycle once the coil temperature is back well above freezing and it realizes all the ice is gone, the carrier as soon as it goes into the defrost. If I'm correct, it's going to be in defrost for a full 10 minutes unless, if we're jumping out these feed up pins, which would speed up that process alright, so I want to cut in here real quick. You can see.

This is the information for the carrier. Defrost sequence for the kind of the standard carrier defrost board, and it does automatically run for 10 minutes if the coil never gets above 65 degrees plus or minus 5 degrees for the defrost thermostat to open. So as soon as the defrost thermostat opens. I'm at around that 65 degree temperature that it will terminate defrost or ten minutes.

Whichever comes first you're saying the Train, equipments, actually sensing the coil temperature - and it knows when to come out of defrost based on that sensor yeah, once the resistance is back within range for a coil to freezing, you will go back into the heating mode. Another thing that I didn't realize is on these defrost settings on there's a 30 minute, 60 minute and 90 minute setting. But what that is is that's actually telling the board went to check whether or not the defrost is open or closed. Those are normally open.

So, if that defrost sensor is closed on the carrier, that's when it's going to go into it's 10 minute v for us, so the 30, 60 or 90 is how many minutes it will take between each time that it texts the actual sensor to know whether or Not it needs to go to defrost frame, doesn't have any of those adjustments it does it on its own, has its own algorithm when it's freezing it goes interview for honestly, it's not so whenever that coil drops below 34 degrees once it once is bureaucracy below that Temperature, I think it's it'll go into defrost, there's a set time after that. I can remember what this set time is. It might be 20 minutes after okay, it cluttered it. The thermistor goes there and you will go into supplies.

So a lot of minute. There's no set jogs, you can change so as soon as it senses hey. I need to go into defrost. It runs for X amount of time, and then it goes into a defrost cycle.

At the same time, the entire defrost cycle - it's sensing, whether or not I'm ready to come out of the office based on that sensor and once it's back in the range and for heat pump, it'll just automatically go back now. So in Florida a lot of defrost times on trains will probably generalized, maybe six minutes, eight minutes, possibly or less it just depends on the climate and he pump doesn't run as much in Florida. So it sounds like testing the defrost cycle on a train is actually a little bit easier on very simple. You simply just jump it.

Okay, so there's t-test fancy jumper those out. It goes bit of defrost cycle on jumper them and it goes back into normal operation. Yes, now the defrost will not work unless you have 24 volt power. So if you come up to defrost Control Board and the little green LED light, isn't blinking, you need to find out why you don't have 24 volt power.

If you have no power, you have no defrost cycle period. It will work at everything. That's a really good thing to note on most boards you're going to need a constant 24 volt source of power, whether it's a blower board, a defrost board, pretty much any type of board you're going to need that constant, 24 volts present. Another fun thing I want to go over is checking the charge, so we went over the process on how to check the refrigerant charge and heating on the carrier system.

What's different about the carrier versus the train equipment, well, placement of the true suction port. You pull the side panel off of a train and the newer ones, the really really old ones, prior to like 1999 2000. They have the charging ports on the outside, in addition to the to the king Belfort's. So I'm going on to the side panel near the reversing valve yeah on the side panel to the control panel, where you can see the reversing valve and everything in the middle pipe that goes to the common suction is going to be the little port.

You put your suction light on that and you leave your liquid line connected to your liquid line port. The metering device is well within the machine. Well well away from that, so you actually do have some liquid coming back to the outside unit. At that point and the hot gas the same way your discharge goes inside.

Oh that's, the same is just where the ports are a little different, where the metering devices is a little different, so carrier has the which is right before the liquid line service valve. So on a carrier system, you can't check your liquid because it's after your piston, so it's not your liquid line anymore again, this isn't heating. So you actually just checking your discharge pressure and your common suction pressure wears on the train. They have the TX v inside of the condensing unit, so you're actually checking a sub cooled liquid.

Yes - and you have probably four or 300 feet of pipe before the meter device from that point, so you are true: liquid sub cooled liquid at that point, carry your equipment. The reversing valve is energized and cooling. How is that on banks right defrost cycle? We saw the fan drop out is that the same fan drops out most equipment. All the defrost cycle is the same anything you want to do for uh something you want.

The outside fan to shut off even Rheem carrier temp star, which is the carrier brand ever barred different ones like green bar, will energize the reversing valve in heating, so very different than that aspect. But the actual defrost cycle across all equipment is going to be the same. They like the function of it. Turning off the fan, reversing the gas.

Turning on the heat strips that all stays, the same, how the board's read and how they timed and how they adjust. Those that's different from equipment where you go pepper gauges can different. It's the best place to find information, so you're checking your sub cool you're, checking your common suction line on a train. Where do you find information on how to know whether or not that will prevent it's correct on most train systems if they're, intact and service technicians don't kind of cannibalize the systems? If you pull the door off there's a packet in an envelope that sticks to the door, you pull that door off.

That has all your respects or, depending on what you have dorian temperature. Is your indoor entering the coil and you go by that chart by the pressures and everything and similar to every other manufacturer? You just have to go by our chart and cooling and heating. All that information is within that pack of the paper is that can be similar to the carrier where it's kind of a overall view. So you have to select your times you to select the indoor temperature amps.

It's like the outdoor temperature to find which earth that's your speak, yeah, anything different on the indoor unit. So, on the indoor unit of a carrier we have our kuhmo TXV and in heat mode, when the refrigerant cycle reverses we're just we're still going through our TXV. But it's completely bypassing us, that's not actually restricting it whatsoever, yeah that the same some some of them are. The newer trains do have that now, I believe into Parker spoiling the previous ones.

They would have a bypassed and a check valve, and in order for the gas to work in heating mode, you had to bypass the expansion valve and it was just literally a loop back around the opposite way when it was in cooling mode. It pushes that check valve it stops it and forces it to go through the txb on the inside or the outside, depending on what mode you're in is how the check valve works. This is one inside and outside on the owner equipment. So for you that don't know and you've always wondered okay.

What is this little weird, that's kind of bypassing the TX be. What point is that? How is this even working? It actually has a little check valve based on pressure one direction, it forces. It closed. Cool.

Note you're in your side forces it closed forcing the refrigerant. Through your expansion valve and heat mode, it forces the little pin the other way allowing refrigerant to flow through it. Okay, so it's pretty cool. It's a weird! Looking it's a little bit larger than 3/8 right.

They usually are 3/8 to put as swells to 1/2. Inch for the actual check valve is plenty yes, they're, not really that cool they're really really a big pain, because sometimes they stick and that causes a whole. Another problem trying to diagnose some very, very difficult, whether or not that check valve is actually seating. The way it's supposed to or if it's not seating and bypassing the metering device.

But so when you change that everything's different now that used to sing technology that everyone else uses and it's kind of colorful times on that aspect, when did they have to switch over? When did you see that you know there was that process with the check valve and then whether you kind of see it switch out to the more of a traditional expansion of maybe five or six years ago, because some of the original tam sevens that came out? They were still using those even with the electronic expansion valve, so you would still get the coil and inside the apex of that coil. You just read a big bypass coming around and everything and that they just did away with that and put the new TX keys in and now they bypassed.