A picture is worth a thousand words . A good instructor explaining how things work has gotta be worth 1 million. Thanks again for the great instructional videos.
Very informative video,this one and the EPR video.What I would like to know is how to adjust these types of valves since I recently finished HVAC school,it would be interesting to see Julio,thanks👍🏽👍🏽
I have adjusted them as the unit is running and keep my eyes on the pressure. It gets tricky because you will have to monitor the pressure in the Evaporator while you adjust the valve.
@@AirConAcademy yes sir I always watching all of your video tutorial 👍♥️🇵🇭 and I downloaded it 🫡 your explanation each of part of refrigeration parts are VERY MUCH informative ♥️ , thank you for your your knowledge of experience 🫡🇵🇭 stay safe and in good health everyday 💓
Thanks I just finished doing a test. This and another video helped me get my head around these valves. I was thinking of the spring setting as a closing force not an opening force. So I made a complete tit out of myself in class arguing the spring tightening would restrict the flow of refrigerant. I got a decent chin check but it wasn't sinking in
Thank you so much! I like getting these videos telling me how much it is helping you guys out in the field. I have been doing this since 1979, but I really enjoy passing the information on and teaching! Thank you for watching!
@@analajaji No. Look very closely to how he write down the letter one by one. It's not normal. So, he is really genius because he write the letter & draw with perspective for audiences.
@@yudhisapto3507 he is ambidextrous and can write backwards, i do not understand how he is drawing on the screen he wont tell me LOL Final exam for 3rd year Red Seal tomorrow, thanks for the help and wish me luck!
Very informative video,pls keep them coming.pls make video regarding compressor unloaders,how they work and how to troubleshoot them.thanks in advance😊😊😊
Thank you I am glad you liked the video. I have a video on unloaders, take a look and see what you think of it. let me know if you have other suggestions. Thanks!!!
Hi i have a question its about hot gas bypass. Why nowadays we don't see in domestic refrigeration for fridge and freezer this method to use in defrosting the machine but rather use electric heater defrost? My dad has an old fridge with hot gas bypass defrost and he never have issue with defrost or heater busted. Thanks
Hi, I'm not really sure why hot gas bypass is not used for fridge and freezers anymore. It could be the cost. It is cheaper to use an electric heater in the back of freezer, evaporator fan to run the piping and controls for the hot gas bypass. A lot of times companies make decisions based on profits. But I am not really 100% sure that this is the reason. Good luck and thank you for your question and thank you for watching!
This question may not be appropriate but I have to ask. I'm rebuilding semi-hermatic compressor in a reach-in freezer. It lost all of it's oil and the compressor seized. I discovered the oil and refrigerant leaked out from, guess what, the CPR valve, a Sporlan CRO-10. The end cap which screws on has an O ring, the oil and refrigerant leaked past the cap. Would you say the bellows broke and that's how the pressure ended up at the screw-on cap? I removed the CPR valve, with the cap removed am able to blow air from the inlet or outlet, and it comes out the hole which has the adjusting nut/screw. Would you agree the CPR is bad and needs replacement? Thanks in advance - Jim
Yes, I would say that the bellows inside broke. You would definitely need to replace the CPR valve. One word of caution is do you think all of the oil leaks out? Or is there some stuck in the evaporator? The reason I'm asking this is because rebuilding the compressor you will need to add new oil to the system. If half of the oil is in the compressor or throughout the system when you add oil you will have too much oil. That means she will have to monitor the oil level in the compressor to see if that oil comes back. If the oil is stuck in the evaporator then your evaporator will not cool like it is supposed to. Just something to think about. good luck!
@@AirConAcademy Since I had to rebuild the compressor, I flushed the entire insides. I installed new crankshaft bearings, after being pressed in I had to run a reamer through them because they took a crush, the inside diameter was actually smaller than the crankshaft. A new oil pump was installed, I did not use an assembly lube, just smeared POE oil on the journals. I chose not to remove the pistons or the valve plate. New poe oil was added, the bottom plate attached and all bolts properly torqued. When I removed the CPR valve, a bunch of oil came out of it too. I purchased a new CPR valve, 5/8" diameter instead of 1/2", so I'll have to do the appropriate plumbing to make it fit. It comes per-adjusted by the factory to I believe 60psi.
@@emptech very good! One thing you need to remember is that by using POE oil when assembling, it is constantly absorbing moisture from the atmosphere so it will turn into acid as it absorbs moisture. Real you will need to keep an eye on it when you first start it up and take steps to neutralize the acid that would be created with the POE oil.
Hi. This is a very informative video. I have a situation where the discharge connection to a vehicle A/C compressor has blown out twice about 30 minutes after the system was started up. Obviously there is something wrong with the relief valve on the compressor discharge. Do you think a bad CPR could cause the overpressure to happen in the first place? Thanks
Wow! That's crazy how that discharge connection has blown out! No, I don't believe a CPR could cause this. In a vehicle typically you do not have a CPR valve. Most likely you have a restriction just before the metering device going into the evaporator. I have found out that there is a screen before the metering device in the Liquid line and most of the time you cannot tell the screen is there. If that screen is plugged up you're going to create that high-pressure and blow the line. hopefully it is only a partial clog on that screen and you can see if there's a temperature difference in the line before the metering device. This way you can tell where the screen is and where the restriction is. If it is completely clogged up you may have to replace the entire liquid line to get rid of that plugged screen. Good luck I hope you get that taken care of!
Thanks a lot for the wonderful video. I have two questions. 1. How the CPR will actually work? Is it something like pre-setting of some pressure value or something like solenoid valve? In that case, if it works in a similar way of throttling valve, where does the extra pressure or fluid will go? 2. If the CPR can decrease the pressure, it can also decrease the refrigerant temperature at the compressor suction, right? In that case, I am assuming that the CPR can also help with protecting the compressor from very high superheat at the suction. Hope to get your valuable feedback. Thanks.
Hi! Thank you for sending those questions in. First of all, this regulating valve can be adjusted and it works off of a spring so now once the pressure is set is going to maintain that specific pressure going to the compressor. As the compressor gets high pressure which it will not be able to handle, the CPR valve is going to close down and not allow all of that gas to go to the compressor keeping the compressor from overloading. The pressure is going to back up into the evaporator. What this valve is going to do is to make sure that you do not have too much pressure going to the compressor so the compressor is not overloaded. It does not know anything about super heat so it will just control the pressure going to the compressor. The compressor may be receiving high superheated refrigerant vapor, but it will only be for a short amount of time until the evaporator pulls the heat out of the food and pressures and temperatures become normal. I hope this makes sense and thank you for sending you comments in and thank you for watching!
@@AirConAcademy , thank you very much for your valuable feedback and clarifications. I can understand the valve works on the spring mechanism. Are these valves manually controlled or most commonly electronically controlled? Thanks a lot.
@@mdmuntasiralam774 I do not know if they make some that are electronically controlled. All of the ones that I know are set and they maintain that pressure. They know what the maximum pressure the compressor can handle so they are preset at that so they do not overheat the compressor. Good luck! And thank you again for watching and sending your comments in.
The compressor will be overloaded because it will be getting too much gas coming to it. As the pressure on the suction increases so will the pressure on the high side and the amperage will increase because it is doing more work, and some of these compressors are not designed to work with these high pressures. So you could say we're trying to keep the compressor from being overloaded. It is a tricky situation but it is a must on some systems. I hope this explains it.
As the suction pressure increases so does the density of the gas. Which makes the compressor have to output more work to compress the more dense gas. When a compressor is made for low temp functions. It's made with lower density compression in mind. Which takes much less work for the compressor to handle. The .ore dense the refrigerant it's like shoveling wet snow it's much heavier and hard to move when it's less dense it's like moving fluffy dry snow which weighs less so it's easier to move.
Hallo Julio, could you please do a Video to explain how could an evaporator handles 100% warm outside air to cool it down to 12C from 36C? should this valve be installed to protect the compressor? what are the other procedures that should be taken in consideration for this All Outside Air HVAC unit without any heat recovery?
Thank you for your request. Let me see what I can do. I have been very busy working on some courses but I am making a note of this and see what I can do. Thank you very much!
I’m not quite sure I understand your question. But let me see if this helps. If we are talking an air conditioning system. The technician should start by doing a heat load calculation to see what tonnage the air condition unit needs to be. The unit is purchased as I said where are the supply house with supply you with, for example, a 3 ton evaporator that would come with the TXV, and they would also sell you a condensing unit. TXV‘s typically have the tonnage stamped on them or they are labeled with their specific tonnage. They would come with the evaporator and if you have a 2 ton TXV and evaporator you would simply just order a 2 ton condensing unit. But first we would have to know how much cooling we need to do or in other words how many BTUs we have to remove from the space every hour. I hope this helped. And I hope this answers your question. Thank you for watching.
What I meant was that for a walk in freezers, eva temp of say minus 20 degrees farenheit to match with a 5 ton low temp. condenser unit,what the role of tumb here?
@@albertspence666 Oh I am sorry I understand now but unfortunately I am not aware of a rule of thumb. I sure wish I had something to tell you. I am sorry.
@@albertspence666 you're talking 15hp compressor ? Because it's 12,000 btu per 3 hp at low temp so 3 x 5=15hp that's 60,000 btu .I think you're running a 5 hp which would be a 1 1/2 to 2 ton valve
