All right so today we're going to be changing the oil on a couple. Refrigeration racks here at a grocery store, not something you do a lot, but we've got acid and the customer wants to low replace. So we've got some interesting refrigerants here. We're going to talk to that and we're going to show you the process of changing oil, changing dryers and also some of the basics of the oil side of a old school rack, refrigeration system.

Okay, so we've got our liquid line. Comes down from our condensers ensures our differential valve pressure differential valve from a very practical standpoint, I'm always looking for any signs of oil, especially on the high side of the system. You're gon na generally find signs of oil. If you have any significant leakage, we do this anytime, we're working at any store, just kind of walk through.

Take a look at everything. Make sure that you don't see anything abnormal make sure you don't see. One particular fan that's off where it shouldn't be. Now again, you can have fan cycling but of course, we're Florida middle of summer.

It's going to be 95 degrees outside, so I'm making sure all the fans are running. I don't have any abnormal noises and, like I said, oil is always a huge thing in refrigeration. The line comes down goes into the receiver in the top that we've got a ball valve here, but then you come to the bottom of the receiver goes into here and then up the dryer, and then it goes up to our liquid header. These are all of our liquid lines to go out through the pain these suppressors have these fans on them in order to provide additional cooling to the head, it really depends on the compression ratios and the type of refrigerant being used, whether or not that's necessary using Alkyl, benzene oil, that's better oil return than mineral hot gas defrost.

What happens is the hot gas comes in through the suction line, because reverses goes through here goes through the coils you ads-b to use to remove ice from the coil along the way in the coil. It will condense to a liquid when it condenses to a liquid. It will come back to the distributor tubes, reverse flow at which it will stop right here before it hits. The txb will go back through the liquid return line and, as you can see, there is a check valve to allow it to go back upstairs and merge it into the main liquid line.

Due to the fact that it has a liquid pressure differential valve upstairs to create a differential in and out to allow this to, merge back in that thing is really nothing more than a traffic cop, and this is one way traffic going through. If we rub this all the way into zero shut that up give it a few seconds, then the cylinder it opens up pumps, hot gas through first liquid log to the header before she's, a main liquid line in order for interval to merge back into the liquid Line we must create a differential between here in there of approximately 25 pounds, so what happens is if this is 190, we'll make this one seat, 175 or 170. The liquid going out will be a hundred and ninety the hot gas. So therefore, the hundred ninety can reemerge back into 170 and this is to create the differential to have liquid returned back to the right, so a grocery refrigeration.

These are your discharged and where they call the drop leg or liquid line. So it goes in this hot gas, so if I can feel which one so that that one there's hot gas I can tell by touching it and then this is the liquid line coming back. So this is all discharge gas going in to the condenser, and then we have liquid coming back going to the receiver. So there's no compressors inside these condensing units for guys who are used to working in air conditioning.

They would expect to see a compressor in here. Instead, the compressors are all lined up in a row inside the motor room. Now it's noisy out here, but it's even noisier in the motor room, so I'll do my best again discharge line going in this is the liquid. Coming back liquid.

You see we have a liquid access port here. Discharge line coming in all these new is just make that change from hot gas to liquid by number one. The super heating number two changing state from vapor to liquid, going in through the saturated phase and then number three sub cooling just dropping its temperature below saturation. So these are all of our compressors, which is why it's so noisy in there and I'm always looking for signs of oil, anything abnormal.

We want to keep these rooms really clean these motor rooms. We want to keep everything clean so that way we can tell if there's any signs of new oil. This is what we call a suction header, so all of our suction lines, coming back from our cases manifold into this to this suction header we have shutoff valve so that you can actually manually shut off, obviously access ports, and then we have our EPR valve with A evaporator pressure regulator valve here we have our discharge and then in behind we've got our discharge header, and this is where the discharge gas from the compressors comes together and then goes out to the condenser. See each compressor has a discharge line.

It ties into the ditch surge header and then each compressor has a suction line, which ties into the suction better, so compressors tie in here and then the evaporator is try and on the other end so like right here, I'm noticing a little bit of oil. So that's something that we would want to look at and just make sure that we don't have any small leaks. This is our liquid receiver, so liquid comes in and out of this tank and it creates a level inside of this tank, another liquid receiver. These are sucking for dryers.

If you take this off, you can access this quarter and replace it. This is a liquid for dryer, again, pull these bolts off and replace the pores there's another one on this one sightglass we can see if we have a whole line of liquid we're here. True, we'll change it within 30 days jewel to do an asset test in two weeks: change the iron to waste. After that dryers are CWS and any changes do tend to plug without fail after 30 days, as opposed to regular 48 60 floors.

The system praise they wall not play. These are the these are the little guys I was telling you about. Oh, you can leave that backed out and then, when you're ready to press the core just turn that in and it opens up yeah. That's like a back seating valve.

Okay, I'm saying yeah! So that way you don't you don't leak any you don't leak any oil out now I only have one of them. So it's not that usable, okay, well cut. The dough usually use low, lunge yeah, but I mean it was low loss. You still can get a little bit of or it can jam or whatever.

Where this you put that on first completely disengage and then when you're ready for a good time, you just turn it in. Oh, my turn that top yeah jerry cans are really nice for roping down. Cuz they've got a seal up. It is only gon na.

Do district precedent? Are you ready, yeah? You know you didn't feel like that. Oh yesterday, now you're depressing before you yeah. That's that's basically like you're installing you a little service valve for yourself. Now now you have now you have full control.

So if you back it out it shuts off and if you turn it in it turns on this cycle at flashing right here. That's a restriction right there, that's also a restriction, that's pretty dirty, it's flavor or he won't explode or anything like that. Yeah going here, lift it up, okay, go ahead and wipe that clean, look right, be careful with echoes in very fine mesh screen, and you don't want to tear the ribbon. Also great, No, you know just brake cleaner at all.

Only the electrical contact cleaner. That's all we think approve here on the right on the right on the right: okay, activating carbon in it just to see the and see them in a little bit. There's nothing wrong with that. Okay, so we do try to avoid an evacuation now, contrary to popular belief about you on this thing, you really should air down into here.

Otherwise you start the system with air in it and then you have non-condensibles. I had fresh sure you run the Russian just be in Florida, that's where we do oysters and I think these old-school little screens on them like your home and lantern screens. The discharge goes out, but the oil separates in this when it drops down to here. This blokes, like these work, opposites needle see in to attack the defensive or bottom of the reservoir, will come out and go into the.

This is an OCD valve. This keeps a certain level of pressure inside here if it gets too high, it just lifts up and discharges itself into the suction header. You see a few different lines going in this section right. I don't even understand that one because it's taken out of the bottom of the receiver or bottom of this, and I think we got right into the section.

So I think what's happening, is it's going thing and it's just depending on the good graces of the diversity. You're gon na fill it up and go down, and that goes in to the suction manner the reservoir. You can see this interesting little thing there.