I'm a truck driver that works in the areas that you service. I recognize a lot of the areas you work in and I'm always looking for your van lol id be super stoked if i bumped into you.. you've taught me a lot more than I already know. And I'm very grateful for that. Great work
@deephorizon13654 жыл бұрын
I've lowkey got no clue what's going on but I still love these videos, very entertaining, informative, and educative! Thanks for putting up these videos to KZbin, man!
@prjndigo4 жыл бұрын
Some twit found the secret self-destruct setting to an otherwise very reliable refrigeration system. Basically having the system set to 37 defrosts a day combined with a weak electromagnet (that slides the valve inside the tube open and closed) grounding was making the compressor fight the defrosts non-stop. The compressor won the battle but lost the war.
@gavincarstens64974 жыл бұрын
@@prjndigo also the bit of copper on the valve seat
@meme-xn6wr3 жыл бұрын
Same bro, I’ve been watching for a long time, and I’m still learning every time.
@rickrojas95643 жыл бұрын
Welcome 🤗
@oxforddispatch97334 жыл бұрын
Thanks for sticking with the filming on this one. Never are one of your videos too long. If I see a 50 minute video post from you I know that quantity WILL equal quality, not just filler.
@TheArchaos4 жыл бұрын
"Its not a slave" For a split second I thought the machine was starting a uprising.
@stephennichols13013 жыл бұрын
Nice to see someone using proper refrigerant practices and diagnostic procedured
@EggHead21034 жыл бұрын
Watching as your acetylene ran out was some of the most suspenseful youtube I have seen in a while. Thank you for the educational and informative commentary on what appears to be an extremely complex system.
@nickwallette62013 жыл бұрын
Haha.. I was really pulling for him. C'mon gas, hang in there! But yeah, at a certain point, you're going to end up with a less-than-stellar outcome that takes longer to do, from trying to make it last than just giving up and getting a new tank. When he threw in the towel, I was disappointed, but had to agree... that was the right call. (But would you expect less?)
@WafflesASAP2 жыл бұрын
I only just discovered this channel yesterday and I know absolutely nothing about HVAC (other than the things I've seen in the 10-ish vids I've binge-watched in the past 24 hours, lol) and I have to agree. I have _no_ idea why I was feeling on edge as he was trying to get that last braze finished before the acetyline ran out, but I was definitely in suspense, hahaha. I'm fascinated at how easily I've become _so_ engaged in this subject matter that I was actually feeling tense IRL like "oh man, dude's been there all day, dealt with several issues, and now this, is he gonna make it in time?!" lol. I had _zero_ experience with this stuff prior to yesterday, so you'd think it'd just be a curiosity to me (as opposed to a source of tension, lol). The mind is weird, and this content is awesome.
@roywall81693 жыл бұрын
I moved into the shop fabricating duct work 6 years ago. These videos bring back fun memories. 🤘🏻
@williamnussey98844 жыл бұрын
Good show. When I run into problems like that, I start worrying about my skills. I end up tearing everything apart to find what caused the problem. I have seen some really strange things happen, but never like the time you found the red plastic cover in the Rotolock . But have found copper in many places it should not be. Keep up the good work. I love your show
@larrybridgers18234 жыл бұрын
Great job staying focused. Keep up the hard work. Much love. god bless you and your family.
@helmsajr4 жыл бұрын
Glad to see you are back up and running. Great Video.
@jwilliams8114 жыл бұрын
This video is a perfect example of what can happen in commercial refrigeration. Great job on diagnosis. I faced that board/valve early in my career and it threw me for a loop. Great content
@scottfarides55164 жыл бұрын
I always hate when the torch runs out of gas on the last braze joint. You have the schlep everything down to the van and back up to the roof. The days just always seem to get longer. I appreciate and thank you for sharing your experience with us.
@jovangrbic974 жыл бұрын
Obviously someone set the defrost cycles to 37 thinking it was a temperature setpoint. Also, there is no way a magnetically actuated solenoid will suffer coil damage due to valve problems. The coil doesn't even 'feel' the valve being there!
@TheLoneWolfling5 ай бұрын
> The coil doesn't even 'feel' the valve being there! This isn't strictly true. The valve position will affect the inductance of the coil, which in turn affects how quickly current ramps or decays in response to transients.
@jefferygrady31814 жыл бұрын
That was a hard one! Great job! Don't be worried about the compressor! It's a scroll and it can take it! When Copland first came out with the scroll I went to a RSES demonstration of the scroll compressor put on by Copland! In one of the tests showing how much tougher the scroll is over a recipricating hermetic compressor or a semi hermetic compressor and a open compressor a test was ran by Copland! They fed bbs in to the compressor and they shot out of the compressor because the screw inside of the compressor has an ecentric that gives when things go thru it like liquid refrigerant so it will take alot of abuse and has now become a industry standard! Remember the Dunham Bush screw compressor that was so durable that it would run for over 30 years with no problem! That is where the technology for the scroll came from! But unlike the screw compressor the scroll is made of pot metal inside and wears away eventually causing it to lock up or the shavings wear thru the armature and short out the compressor! Thanks for another awesome video! In my opinion the turbo torch would have made that job alot easier and faster! I did alot of soldering over the last 35 years and always preferred the turbo torch because the flame wraps around the pipe for even heating and you use different tips for different sizes of pipe! Also it's more economical and you don't have to worry about running out of oxygen and it's lighter and easier to handle as well!
@andrewpierce22134 жыл бұрын
My engineering mind has ruined me, but I have to say it. Heat doesn't rise in a solid. "Heat rises" is a saying that people use because in a fluid, the higher temperature fluid is less dense, thus it is more buoyant and rises above the more dense fluid. In a solid, heat transfers from high temperature to low temperature, regardless of height (to a reasonable extent). Not trying to be a smart butt as you are 10x the technician I would ever be, just spreading some information about heat transfer. I am about to graduate with a Mechanical Engineering degree, and I watch these videos to learn how I can be a better engineer in the future by keeping the people who maintain the equipment happy. I love your thought process on the "whys" of failure, as the engineering students I am around rarely think that way, and that's a crucial part of why we go to engineering school. Keep up the videos; whether you're helping a fellow technician, an engineering student, or simply entertaining the masses, we love it!
@abujamie37634 жыл бұрын
If I have to heat 2 joints, one above and one below, are you saying heating the top one first doesn’t delay the amount of time the component in the middle is exposed to high temperature? If I heat the bottom joint heat rises while I’m brazing then I go to the top joint and there’s more heat all around. You’re saying the metal heats from low to high but there’s a flame that sends heat out and up and he’s trying to minimize his impact all around him especially whatever component is in the middle. But maybe I’m wrong.
@andrewpierce22134 жыл бұрын
@@abujamie3763 The air around the top joint will certainly be warmer than the air around the bottom joint, but the heat transfer via convection is quite minimal in the case when compared to the heat transfer via conduction through the copper since copper has a very high thermal conductivity. So what it really boils down to is the closest joint to the one you are currently heating will generally be the warmest. If you have two joints each 6” apart on a vertical pipe, then yes, the top joint will likely be *slightly* warmer. But the point in all of this way to say that heat doesn’t rise, heat transfers from warm to cool body. It just happens that in fluids, cooler, more dense fluids settle due to density differences.
@Edward-ud8hd4 жыл бұрын
@@andrewpierce2213 Correct me if i am wrong, heat does not rise, but hot air rises.
@abujamie37634 жыл бұрын
@Andrew Pierce Thanks Brother...
@silasmarner75864 жыл бұрын
AIr convection upwards will cause a little heat to increase on the uphill side. It's not a huge amount but if you heat the air, which rises and travels along let's say a rod or pipe, it will conduct a bit of heat back into the pipe on the uphill side. In the solid, inside of it, yeah...you're right.
@watchm4ker4 жыл бұрын
"37! The unit did 37 defrosts a day!" "In a row?"
@ICountFrom04 жыл бұрын
KoL?
@Tevildo4 жыл бұрын
@@ICountFrom0 Veronica.
@jasonmurawski58774 жыл бұрын
And 45 minutes each, this unit was in defrost 27.75 hours of the day
@henryhildebrand42364 жыл бұрын
@@jasonmurawski5877 lmaooooo
@snoopyjc4 жыл бұрын
And the box temp was still too cold????
@alessichris074 жыл бұрын
Damn it man That was a hell of a ride. A good example of what can possibly go wrong on a simple service call. 😉 Loved it !!! Way to push on.
@captainkirk77024 жыл бұрын
It happens a lot more than you think!
@audimaster50004 жыл бұрын
31:34 it’s incredible to me how such a tiny piece of trash can cause such havoc on an HVAC system. Exemplary work!
@captainkirk77024 жыл бұрын
The itty smallest gives the technician hell sometimes!
@Jack-oq5jn3 жыл бұрын
A day in the life of an AC tech great video after 20 years in the trade it’s great to follow a real life service call Thanks
@raminit14 жыл бұрын
I actually dig the longer videos. I’m a residential HVAC tech and seeing the refrigeration side of things are interesting to me and I get a few tips on working on the commercial package units, for the few that I have. Keep it up and I’ll keep watching. Thanks for your dedication.
@jamesh62294 жыл бұрын
I am not an HVAC guy but I worked in restaurants for 10 years. Working with Walk-in coolers air conditioning units and especially ice machines. If I had some of this knowledge back then there would have been fewer problems and we could have recognized when things were about to fail, especially the damn ice machines. Thanks for the videos.
@Ozziethecat3 жыл бұрын
I'm a Chef that loves your videos, it's been helping me understand my HVAC equipment a lot more, and I feel more competent at communicating with Techs about what I think is going on with my equipment. Thank you for all your content, and I love seeing the quality of your Workmanship!
@gbinman3 жыл бұрын
I really enjoy your videos. I actually have no interest in commercial HVACs at all. I do enjoy following your logical troubleshooting. I have experience in auto mechanics, low voltage circuits, medical care and computer networking. The techs are totally different but the process to resolve issues is very similar. You are a good diagnostician.
@vicenterivera693 жыл бұрын
What a pain! This happens a lot! What I mean is that you think your done...and BOOM, rare situation pops in! Glad that your real on your thoughts, the way that you record it's like a real day on the job. Nice And THANK YOU Hope You charge the client real good. Lots of work and material there. 💪
@OcRefrig4 жыл бұрын
The simple answer is “ That Beer can NEVER be too COLD !!! “ Good vid ! Yes , that scrap of copper was from someone cutting or Reaming a Pipe poorly and Leaving a Shaving hanging inside the Pipe. It finally detached it self from the tube and blew its way down the pipe. Great find !
@melissachartres32193 жыл бұрын
... until the beer comes out in solid chunks! Here... eat your beer.
@NotSoCrazyNinja4 жыл бұрын
Why am I watching all these HVAC videos? I don't even have a central unit or any major refrigeration. I must say though, rather interesting. I love problem-solving and love "fixing things", and your videos are loaded with both of these.
@BenTh174 жыл бұрын
That copper chunk in the headmaster was a special gift from heat craft just for you!
@richardpowell1814 жыл бұрын
Christ this video was brutal to watch. The highs of replacing the expansion valve, the lows of seeing the bypass triggering, the further lows seeing the outdoor light gradually turning to evening with no end in sight.
@richardpowell1814 жыл бұрын
Truly a saga any engineer knows :(
@potatolew4495 Жыл бұрын
I have been repairing refrigeration, HVAC, and ice makers on commercial fishing vessels for almost 30 years. Though some systems are different, like using water to cool the condenser as opposed to air. I have picked up many good tips on checking certain components. Always try to keep learning. Thanks for sharing this great content.
@dericcs9214 жыл бұрын
I really enjoy watching you trouble shoot and enjoy your videos. Personally I enjoying trouble shooting difficult issues that others can't figure out. My line of work is very different from yours. I really enjoy watching you trouble shoot. A long video and I know it was very frustrating issue but I really enjoyed it.
@jameshendry99064 жыл бұрын
I know this video was a long one but your long videos are the best ones I’m sure it was a pain in the ass to deal with all that but it makes for a very good content thanks for passing on the knowledge
@killerBGarage Жыл бұрын
I feel you man. I've been doing commercial refrigeration for 15 years. This one had me frustrated watching. Keep up the good content man. 👌
@ront1573 жыл бұрын
Love you videos, I’ve been a residential tech for 8 years and just made the jump to commercial earlier in the year and this helps me learn.
@tracysellman1562 Жыл бұрын
Chris, I had this same issue head-master by passing but only every now and then and then the internal scroll leaked by and fought the pressure control, this was new install only two months old and we had to install two pressure controls. Heath Craft just sent us authorizations to replace the whole condenser, everything worked like it was supported to ,for more then 2 years after that.
@EricK-ig4ko4 жыл бұрын
The best HVACR in the business!!!
@spearvlogs83474 жыл бұрын
No one cares Ok
@RideCamVids3 жыл бұрын
Chris we all have these sorts of days, you find one problem and you fix it, then it shows up another problem which then takes you on to a further problem. Good call on staying the course and chasing the ghost in the machine.
@HVACRVIDEOS3 жыл бұрын
Thanks bud, I am going live on KZbin this evening 8/9/21 @ 5:PM (pacifc) to discuss my recent uploads and answer questions from the livechat, KZbin comments and emails, Come over and check it out kzbin.info/www/bejne/m6mxpH2Iqcp3hbc
@josephconway19683 жыл бұрын
Your watch makes it into view at the 19:(02) minute mark. I can't be the only one who said that is cool, I want one! What is it? If its Apple , not for me. GREAT video!! Even the calls that seem to test you, you still have a great way of explaining your troubleshooting process! That, to me is probably one of the more important things you do! Its to easy for someone without your experience to get overwhelmed by the scope of how the entire system works and not focus on step by step. For me, that's why I love watching you work!!
@HVACRVIDEOS3 жыл бұрын
It's a Samsung Galaxy active 2 watch with a supcase band
@karizmatic54 жыл бұрын
Thanks again, Chris. Love your videos. Truly.
@captainkirk77024 жыл бұрын
I think you did a very good job of all your diagnosis, I’ve had them every so often just like what you had! Hair pullers! Multiple offenders that throw you off! But your persistence was correct! That compressor within a few months weeks to a month or so is going to crap out on you. Seen it it too many t! This one is very good teachable moment! Keep it up Chris! Keep plugging!
@aungthiha50504 жыл бұрын
Hey Chris, i been repairing lab chiller in my company. They use EEV. When i faced the symptom that temperature keeping lowering although u see the step is zero in your PCB, then i replaced both EEV coil and valve together. But what manufacture say is always keep one spare EEV coil to comfirm whether it is coil or valve issue. They dont say what cause EEV coil to fail. They say it is either coil or valve when u r having temperature unstable problems.
@vanmarcell60403 жыл бұрын
I have seen this very thing about year ago. it can drive you crazy. Great job.
@yz250a2 жыл бұрын
Your persistence is commendable.
@richbrockmeier3922 Жыл бұрын
I show your videos, particularly this one, to my techs here in Asia. Big picture through small details. This video is super instructional. As always, thanks Chris. 🍺
@jonathan_calixto4 жыл бұрын
Like someone said, I dont know anything about these types of things but I enjoy watching the videos.
@jerryfrigeration2 жыл бұрын
You make a bunch of great videos. This by far has been my favorite. Thanks
@jamesmooney53482 жыл бұрын
This was a good one! Thanks!!!
@ianorr7604 жыл бұрын
That was a tricky one Chris, no doubt frustrating for you but these are the ones we love as techs... great work mate 👍🏼
@MrRealtalkME4 жыл бұрын
Video of the year , even with everything happening still was able give great info
@Goldstacker1972-kp2bh10 ай бұрын
I've had that happen several times with those txv and it was because moisture got in the head of the solenoid valve. If you run across that problem again take the head off the txv and dry it out good then put it back together. I've done that on about 6 of them and it fixed the issue everytime.
@jamestoy4264 жыл бұрын
The thermo imaging camera would have helped hear to see the head master bypassing nice job l learned a lot here I was ready to replace the compressor again nice job thanks for the video
@EduardoRamos-lm3mk4 жыл бұрын
Thank you for your videos it really helps me to figure out when I encounter similar problems.
@Muslim9414 Жыл бұрын
Thanks man for what you doing
@natepeterson71454 жыл бұрын
Thanks for the video, perseverance paid off.
@Ted_E_Bear4 жыл бұрын
Another awesome video Chris !!
@jeffreykubiak51264 жыл бұрын
Good job Chris been in a minute! Since viewing! Stay safe got Hurt bruised knee cap fell down steps coming down from roof!
@craigcork90004 жыл бұрын
Carel e2v coils fail often here in uk (aldi supermarkets). When the coil goes faulty the body is stuck in its last known position regardless of what steps it thinks it’s at. Probably just a new coil needed but nevertheless job well done. Keep up the good work :)
@AmericanLocomotive14 жыл бұрын
...and of course Carel will just refuse to sell the coil. Even if the EEV was mechanically stuck, it really wouldn't cause the coil to burn out since the control doesn't continuously keep stepping the valve.
@WafflesASAP2 жыл бұрын
@@AmericanLocomotive1 is this true? does Carel not allow customers to buy the coil separately?
@raya51134 жыл бұрын
Bro..... there are few who understand what it takes to be successful in this field. This video captures a part of it. I watch your video on my off time. Thanks for taking us with you on this one. We really appreciate it.
@hvac014534 жыл бұрын
Those pesky hot gas controls can cause lots of problems. When you replace them, make sure to don’t install the new ones without first making sure to order two inlet screens first, they unfortunately are Considered optional, don’t ask me why... also when you have the king valve front seated, and the gauges on the left service valve, how do you expect to read the compressor high side without an additional pressure gauge on the discharge line. If you had, you would have likely seen the head pressure climbing way up
@hvac014534 жыл бұрын
I had the same problem and it was reading some real wackyshit and it was the TXV AND the HGB. I think when the HGB fails it kills the TXV.
@fritzjean-baptiste59354 жыл бұрын
Always big picture diagnosis. Good job brother. I learn a lot of good things from that video.
@SidebandSamurai4 жыл бұрын
awesome video, shows the problems you run into when working with these systems.
@kerrydavis29192 жыл бұрын
Great video! Thank you for filming your thought process. It really makes for a good video and I always pickup on some information.
@hkhvac2704 жыл бұрын
Best ever troubleshoot steep u are the best good luck thanks for sharing u knowledge.
@tjrogers40793 жыл бұрын
Excellent job! BIG PICTURE!
@XTreMe2k64 жыл бұрын
this was a mess but it gave us a extra long video and i enjoyed every second of it :D
@TheLenaweeTrekker4 жыл бұрын
The very first time I ran into one of those those systems was at a Little Caesars. I was on the horn with tech support, and told them what I had found and followed their directions, and they said to replace the solenoid coil. I asked what could have caused the coil to fail. Tech support told me they had a run of bad coils. Ok, it was still under the warranty so we do what they say to do. So I changed the coil. Unit was working great again. Three months later, same thing happened. This time tech support tells me to change the EEV, EEV coil, sensors, and the board. The manufacturer's paying for it so Ok. No more problems from the system to the best of my knowledge. Given what you found in the headmaster valve, there may have been smaller copper particles that got to the EEV and were jamming the valve up enough to start burning out the EEV coil. I think I will miss the big Sporlan TXV tests with the magnet on the valve. A good solid fast "thunk" and you know it's just a burned up coil. And a weak quiet valve would get replaced or rebuilt. Oh well, that's progress. So they say.
@xraybravo71804 жыл бұрын
I have watched the video to the end, great work and great skills man.
@dennisedwards75244 жыл бұрын
I love the way you question yourself while you are trouble shooting! Several times I found myself thinking the same thing you are saying. I also love how thorough you are. Could you mention how you talk to the customer to get them to go along with what you are doing. This was only the 3rd video I have seen. I look forward to going through all of your videos. Thank you so much and keep up the great job!
@maaltagabriel4 жыл бұрын
I understand what he says but I don't know what he means. And I still think these videos are amazing content to watch. Keep up the great work!
@Abhishek-C924 жыл бұрын
Honest HVAC technician till date without any bullshit talks. To the point jobs.
@captainkirk77024 жыл бұрын
🤔
@k.sullivan63033 жыл бұрын
Then I'm thinking probably the board. Then I hear it from you 2 seconds after I continue the video. This is hilarious! Somebody stop me!
@ngreed4 жыл бұрын
Great video! I don't mind the length, it helps show the entire process.
@kevinpoore56264 жыл бұрын
Sounds like you're having as much fun as I did today I live in Greenville South Carolina and we just got slammed my hurricane Zeta trees down everywhere big tent no longer big Palace crafts but Keep On Keepin On
@saturninorangel23552 жыл бұрын
Perfect gob hi Lauren every year with your videos thank you so much appreciate thank you again we lord we learn we still learn thank you my friend I am Mexicano
@silasmarner75864 жыл бұрын
I fell asleep a couple times but I slept-learned what you were doing and oddly followed along the entire time!
@haydenuk024 жыл бұрын
Great work as always and thanks for the content stay safe and take care
@Alex-nf5go3 жыл бұрын
Love your Show bros.
@stephenhunter704 жыл бұрын
At 28:31 I'm thinking the solenoid went first due to to many defrosts everything wrong in the condenser on the roof may have been the result of to many defrosts. At 35:42 I'm thinking the extra defrosts may have been configured due to the faulty head pressure valve on the roof. I'm also thinking that compressor is not long for this world.
@tomoliver84984 жыл бұрын
Me thinks someone from the bar fiddeled with it and thought "37" was the temperature setting
@michaelbuckley38084 жыл бұрын
Chris, we had a similar issue with our QRC controller. The electronic expansion valve was bad. It was replaced. The plug end on the electronic expansion valve solenoid has 4 pins. It's not a keyed connector and It can be plugged in incorectly.
@FlyEaglesFly191114 жыл бұрын
You can always use the silica inserts on a leaking flare fitting to get it tight and no leak.. they are a life saver. I was wrong on FB about wrong refrigeration. But you said something out of the norm
@GB-ue6wr4 жыл бұрын
My man, I envy your knowledge, but not some of the jobs you get. Great job, you are the man!
@killah_turtle60384 жыл бұрын
Love your videos!👍
@ronaldscott22844 жыл бұрын
You are a thorough kik ass tech i just learned a ton of shit from you i love refrigeration but have only done simple fixes you are the man im going to subscribe!
@CHOMAHOMA2 жыл бұрын
Thank you for this video. Learning a lot.
@KadirYildiran4 жыл бұрын
Then I was able to watch the whole video. How hard you have worked. I wish you convenience🙏🙏🙏
@jefflarocque31464 жыл бұрын
I do not do this for a living but I find your videos fascinating. I can appreciate your attention to detail. Very professional!
@HappilyHomicidalHooligan4 жыл бұрын
The best analogy I can think of to explain the Wet Rag heat compound is it's a battery that deals with heat instead of electricity... You put it on and it charges up as you braise the joints but eventually, it can't absorb anymore heat - the tank is full and it starts discharging that heat into whatever it's in contact with, either the component it protected or it's storage container...what receives that discharged heat depends on whether or not you cleaned it off the component soon enough...
@michaelgibson39494 жыл бұрын
Watching from Australia love the vids mate
@antoniofabro37594 жыл бұрын
Thanks for those videos was a pain but u got through it ! Keep it up
@gregbowman35984 жыл бұрын
Good one Chris👍
@ThePete24324 жыл бұрын
Heatcraft got me in a similar way, had a copper curly-q in a headmaster a couple years ago
@donnierobertson30884 жыл бұрын
Great job and video like always
@qualitybarsolutions61074 жыл бұрын
Wow, that was some job! Fantastic job! well done 👏🏻👏🏻👏🏻👏🏻
@harrydickson45754 жыл бұрын
Another excellent job and video 👍👍👍
@persimonsen87924 жыл бұрын
Those valves are easy to damage during soldring. They don't take that much heat. You should get the service magnet from Carel. Then you can manually open and close the valve. Had one on a large CO2 system, where the controller was off for 2 weeks, and the coil still iced up. It was with a PJEZ0000C controller and a EVD driver module.
@sublim90083 жыл бұрын
I recently finished my studies as a technician in domestic and industrial refrigeration ... I love your videos :D ... give me a job :P
@aarondelauder81964 жыл бұрын
Great video thank you so much!!!!!
@AKStorm494 жыл бұрын
Great video Chris. That was a hell of a call.
@NoDissasemble4 жыл бұрын
Great to hear your logical process for problem solving. The synchronisation of valves to controller is a problem I've encountered in heavy industrial systems. I had a massive 6.6kV water chilling plant where the valves had resistance position measurement fed into a 4-20mA transducer then into the controller. They had a tendency to drift over time so you had to recalibrate the relationship of 4-20 to real position.
@christiansommer9144 жыл бұрын
Wauw Chris, hat off to you for a great job.. Pro diagnostic 🥇
@koolhub5891 Жыл бұрын
Those pressure controls/ cut in and cut out are tricky, I worked in a Ice Plant where we ran R-502, and R-22, but we ran R-717 Ammonia Freon, with water cool towers. The Freezers in door evaporators, and the condensing units had those cut- out differential controls, I remember when the evaporator coil ice up, and iced up to the low side suction line, the compressor was off and the fan too, so we reset the low side pressure control, and check the high side, and the systems came on, the defrost clock timer was ok.