It's really hard to have shorts with ice from condensation or water vapors since it doesn't have any minerals in it and it doesn't conduct electricity.
Well, that's only true if there's no metal in the vicinity which isn't the case here. Some of the metal will be picked up by the water and make it more conductive than pure water. But for a real short you need either a high voltage, or you have very close connections. Just some water next to electricity with 1-2 cm to travel to the next ground, will have way too much resistance for a short.
Ice tends to be "pure" water. Minerals that can act as electrolytes are pushed to the center as water freezes. Or as mentioned, water vapor will be pure also. That makes ice relatively non-conductive.
I think you do a great job with every job you show us. Always making sure the customer is happy. I really enjoy watching you teaching us. I looking to get into commercial hvac from apartment maintenance. I’m enjoying learning from you. Thank you sir for your time to teach us
The plugged strainer likely slowed refrigerant velocity. The slowed velocity aided in poor oil return. Correcting the problem with the valve might possibly allow the return of oil. Cycling the unit sevral times from operation to pump down likely would scavage the oil back to the compressor. Piping design might play a role but what you had there isnt uncommon piping from what ive seen although likely not the propper way. Id honestly do a few pump downs and let it run for a week or two and return to see if the problem possibly resolves its self. We never had thermal cameras back in the day and often were listening to the old timers wisdom. As you said in the video it is hard to know if its a feed issue or a oil log. Could also be trash in a capilary. Customers dont realize alot of out work can be guestimation based on experience or the data we obtain on site as you generally never run into the exact same install because its field fabricated unlike say a car built on a assembly line
Industrial Refrigeration always have traps -- even with the CU less than 10' above the evaporator. Rarely see commercial apps with a trap for oil return.
I'm missing something. How did you come to oil logging from ice build-up? Everybody is so excited about this "oil problem" and I see no direct causal relationship between stated problem and this diagnosis. Any help will be appreciated.
As a mechanic of 5 years, I can tell you, assembly line or not, the job is still NEVER the exact same due to several other factors and variables that come into play. Every vehicle has it's own story, no engine is ever given the same demand, and no vehicle goes through same places or terrains/conditions. Every damn year and model is a completely different design nearly. There is a design that the engineers have put in place for the HVAC system in every vehicle, they have to route everything to fit just right, that is true, but that does not make them impervious to imperfections, random mishaps, McGyvers/DIYers, untrained individuals, or poorly thought out engineering from turning them into just as much of a complex nightmare. The guy that takes his shit to the river is gonna have a lot more chances at stuck bolts/parts, broken bits/plastics, and unforeseeable obstacles than any vehicle that sat in an air conditioned garage most it's life. Automobiles are introduced to some of the most severe weathering conditions and demand. Much more severe than a stationary slab on the side of the building. No matter what, it's all hard work, and takes a lot of skill to be apart of.. Most of all, it ain't easy fixing things so that they not only last, but so that it doesn't happen again.. There are tricks to each trade that you aren't going to know unless you're apart of it, but it'd be nice to not see the trades be devalued by one another simply because they "think" the other trade is somehow easier, when they each require the same amount of time, effort, and devotion to be considered a "professional" at.. My diagnosis would be blockage in the system.. Causing a difference in pressure in the bottom part of the evaporator.. Hence all the icing. Restricted vein in the evaporator. Reciprocating compressor that's been changed before.. If the system wasn't properly cleared of debris the first time.. Makes sense that some bits could finally make their way to the Evaporator causing this condition. That is my guess based on my roundabout knowledge of automotive A/C systems..
a lot of good comments here although they all seem to be saying the same thing to me. you can mess with the plumbing all you want but you still end up having to reinstall the windows or replace it with Linux. Yeah I do Mac windows and Linux support same mantra. Lol you build up knowledge of the field and half the time you're guessing at what it can be or there's even where Crossing fields of knowledge helps make you thank what might be the problem from some unrelated thing.
This kind of difficult diagnosis videos are priceless to learn & avoid all the work it's done, for instance, swaping that TXV a saturday night. Can't express to you more gratitud to take the time to film that kind of things. Thank you very much Chris, I've become a better tech observing & thinking more and working less hard thank to your teachings.
I used mine in the same manner. I once used it on a Scotsman ice machine and clearly saw only half the cutting grid was working. That cutting wire doesn’t get too God awful hot.so it shows the difference nicely
Oil logging. I've had some success by pumping the system down, linking out the defrost & cooking the evap coil to lower the viscosity of the trapped oil. Then opening the receiver valve so that the sudden inrush of refrigerant pushes the runnier oil out of the evap. Repeat a few times & it should do the trick.
Now this was a good call for a lot of people out there on this video. Oil log is not something you see every day but it’s out there and can make you scratch your head!!! This is a teachable call even for me!!! I would have gone the same path but when I was first starting in the business this would have drove me crazy!!!
@@HVACRVIDEOS its always like that.... i had the same thing... it failed the day before... (started acting up) lets call at 4:30pm on a friday so Thursday Afternoon till Friday 4:30..... SMH LOL!! that Compressor AVA 2490 its Heavy Noisey BUT its a work horse
Right ? Must not have had too much expensive product in the freezer. But, I have worked (I am a chef) for owners that hope for a miracle that it will straighten itself out. I have always been a huge fan of preventive maintenance. You see frost... I call "The Guy". If you were on the East Coast, you'd be "The Guy" that I'd call. Damn, you're so thorough.
Your method is the same approach I would have taken. I disagree the coil is oil logged conclusion just yet. There are 2 other points I would consider to further evaluate before going with oil logged. R502 system originally. Now r404 compressor in a 502 condenser coil. R404 needs a larger condenser coil by design. r404 cannot be a direct drop in for r502. Your SUBCOOLING was low at 3 degrees in my opinion, usually 8 to 10 degrees is what I see even with a receiver. So I'm wondering if your liquid is not subcooled enough and flashing off before the distributor. An evaporator 1/2 colder on bottom makes me also consider a second problem, your nozzle could be oversized. Liquid and vapor separate, based on density, liquid bottom half of coil and vapor top half. This coil frost pattern problem could have been around for a long time.
You are on the right path! If your customers got a solid 20 years from a unit they shouldn't expect much more! If you repair the evaporator coil tomorrow it may be the roof unit! You have given the best advice.
im allways amazed that your electronics are so open and fly wired. In germany we have to put every electric connection inside wireboxes and such so they arent open
Just an example: You cannot drill a hole thru a wall and stick some pipe or some wire thru it. You need to have it sealed against fire breakthrough with special mortar.
David der Kabauter its legal to have wire nuts connection inside equipment. Equipment cover is a box so no additional box need. Same as canada i dont know what u guys talking about. You guys have different NEC code book?
I think you nailed it when you mentioned that it used to be 502. They likely never attempted to blow out the evap and the oils mixed and fouled up over time. Probably turning wax like. I’d cut a couple sections out see what comes out.
Appreciate how thurough you are. I've learned a ton from your videos. I've been doing hvac for 5 years, and just started doing refrigeration a year ago. Keep it up!!! Thanks!!!!
It’s hard to tell how much oil is in a system with the hermetic compressor unless it has A site glass in the compressor. But you’re probably right the oil my graded from the previous compressor and there’s probably too much oil in the system. Great analysis!
I had an emergency service call at a chick fil a about a week ago. The manager told me “The freezer has been temping around 10 to 15 degrees for like three weeks but we were concerned today because the temp has been above 18 degrees and we can’t allow it to get too warm” lol this took place on a Thursday night around 8 pm!
I dont have any knowledge or experience with HVAC nor am I looking for a career in HVAC but these videos are awesome to watch. Its the "fix it" bug in me that keeps me watching lol
Wow. I'm having flashbacks. I studied refrigeration and air conditioning in a good JC vocational program, right before I joined the Air Force in 1983. I then was trained at the Air Force's civil engineering refrigeration and air conditioning technical school at Wichita Falls Texas. Everything you're discussing is coming back to me. You are very good at describing systems, sharing your troubleshooting process, and also teaching the overall mindset you have to put yourself in, if you are going to really fix a problem. You are dead on about how important it is to be thorough and honest with customers. It is not easy especially when we accidentally screw something up (as we all do). It still pays off, because you gain trust. If you haven't already done so, you should consider looking at being an instructor somewhere.
Nice work Chris, You went for the least expensive option for your customer, Oil logging is not worth the repair Because you could have had bad components due to oil loss and now your on the hook, NOTHING GETS PAST YOU AWESOME STUFF THANKS FOR SHARING
Videos like this make me happy I only work on vehicles in my driveway LOL. However a lot of respect goes out to you guys who deal will all of these issues so that we can have a comfy life at the restaurants and places we visit. The amount of Knowledge and Experience that goes into being an industrial HVACR Tech is amazing. My hats off to you guys! Thanks for sharing. Best Wishes & Blessings. Keith Noneya
Reminds me of the 3 dr rif with the cap tube I spoke with you about. I ended up going back, replaced the cap tube again, drilled there accumulator in there evap coil, got some oil out, restarted it and still had low suction pressure compared to what I'm used to. Total waste of time, so I agree it's time for a new evap coil. It could also have a little bit of a restriction in the distribution tubes. Who knows. Total guessing game at times, good video👍👍
love it mate. youre well setup and so thorough with your inspections! Im in AC and sometimes need to dive into mid temp + low temp and it throws me off at times. You are an excellent methodical explainer
Water is actually a lousy conductor, and ice from condensate is basically distilled water. It's all the contaminants (like salt) that water can pick up and dissolve that makes it conductive.
Not an HVACR by trade, but have done my own residential stuff while buying a fixer-upper. I found your videos through related searches and got addicted. The way you diagnose and work these issues is fantastic. If I was in the need of a tradesman of any kind, I truly hope I get one that is like-minded to you. Customers emotions can be a unique thing, but your work flow is always in their best interests.
I work as a locksmith and I can’t tell you how many times someone realizes their issue Friday morning at 7 but waits until 11:30pm to call in an emergency because they “can’t secure the store.” Then sometimes I’ll go out there and it’ll be something stupid like a back door alarm that has NOTHING to do with securing the door. (Passive alarm to alert when the door is opened)
I found this video very interesting! I have an understanding of automotive A/C systems, went to school for that, and I've been thinking of going back to school for commercial HVAC.
Whats worse... I'm probably going to watch it anyways... And start getting recommendations on other similar videos... Next thing you know, I want to be a freezer technician...
Thanks for this video. Yes its difficult to flush out the oil from the evaporator ,since u mentioned P/U traps. Could u pls, show us how the piping could be done for better oil return.also with a system that has multiple evaporator s,connected to a single condensing unit. Lastly what about an oil seperator being used. Thanks.
Hello, I enjoy your videos, as I used to be in the trade. I’ve seen this one before- when you had the system running, look at where your frost starts- it doesn’t start at the valve, but at the distributor. I used to have to play around with the distributor sizes to get it right on retrofits or old mismatched equipment. Ive even drilled some out the next size up. The literature will tell you the size for given refrigerant. (Although its just a guide) That being said, when the box is down to temperature, that is when you look at your pattern. Too large a orifice, the refrigerant doesn't have enough velocity to shoot through the tubes evenly. Midway and up, the coil is dry. Too small of an orifice will feed evenly, but the superheat will be way too high for oil return and performance. Gut instinct tells me it is a bit too large, but I don't know how cold the box was when you showed the system running.
Sometimes you can get the oil out by flooding the evaporator. Drop the bulb in hot water and let'er rip. Obviously be careful with the compressor so you don't flood that too. I think it's less likely that it's a distributor or capillary problem owing to the pattern of frost. If one or two loops had problems, sure. But we're frosting up more in the bottom and less and less towards the top. Another thing, but i don't really see how it would be happening in this case, is an air flow issue. I experienced this when working on Liebert units in data centers. They had a little plate on the back of the coil presumably to hinder the air stream from blowing condensation out of the drain pan, but it also had the adverse effect that the lowermost loops would have the air flow restricted, thus causing the expansion valve to close and the upper loops being starved of refrigerant. Very difficult to get adjusted. In time we just got rid of those little plates and lo and behold we could get the evap pressure up significantly and it was suddenly a bliss to adjust the valves.
If that riser is less than 3 feet a trap isn’t required, but I would still reverse trap the top side to prevent oil draining back to the evaporator from above. If it’s greater than 10’, use a velocity riser.
i had a call for a unit flooding really hard back to unit.coil had some frost on it not enough to restrict air flow.what i found was a coil not flooded,but still liquid was coming back to compressor.the coax heat exchanger in the case had broken internally liquid wasn t going through txv. but dumping directly into suction line back to compressor.by passed liquid line and that solved my oil failure issues.
Great great video this is/should be one of ur best videos and u have alot , but I said dat Because this is not something u run into often and the lesson to be learned from this is priceless..great video Chris.
I always was told, when the compressor is above the coils, you put in a ptrap. After hundreds of service calls, I very seldom see them. I prefer to put service ports in the box, so I can check pressures and pump downs, without hauling everything onto the roof, we have snow to deal with...last but not least. When you replaced the TXV, you should have had oil come out...but since the compressor was replaced. It was old oil, and the TXV was replaced and the oil drained out from the prior work...
You raise a good point about measuring the oil charge. I’m just an apprentice but the oil logged evaporator diagnosis makes sense. John Tomczaks book has a small section on troubleshooting oil logged evaporators and one of the symptoms is unexplained compressor failures, especially more than one. The plugged strainer likely didn’t aid in oil return along with the missing P trap. Low heat conduction from those bottom coil rows makes sense and explains the frosting. Just like low airflow. Did you thermal image the distributor? Just thinking perhaps there was a restriction on one of the capillary tubes. They all looked pretty uniform in the video though. Thanks for a great video! Always learning something.
Have seen pipes crushed flat due to ice in coils which mess up the flow. Also seen distributors plugged, especially on systems that have been converted from mineral oil.
I just had to fix about 10 univents last week that hadn't been serviced since the late 60s. They hadn't worked since the 80s but with covid the school department seems to think they'll help with ventilation (they have no fresh air intakes). And replacing isn't an option.
Holy hell Bro, that’s an awesome find. I agree with you, just give the customer their best options and go from there. I think you did everything correct and good job.
The bottom defrost coil is pulled away from the evap coil. Possibly having the bottom of the coil warmer will help oil logging by better heating the oil in the bottom of the coil. Push it back into the depression so that it now contacts the aluminum coil again and secure with ss wire tied to the evap tube. If you added a suction filter to the condensing unit then you'd have a port where you wanted it.
Good diag.... distributor lines could be an issue, but now that you have restored refrigerant velocity, there's a good chance in a few weeks the oil finds its way "home"..
Good I have been through such challenges and at times feel like I don't know my work and it hard to explain to the customer. But thump rule from this video always tell the truth and let the customer decide
Just look at the frost pattern on the distributor. The plugged strainer would tell you the orifice in the distributor is plugged. Take it out and let the expansion valve do the work. It's also using a different refrigerant that the original. My bet is that they didn't change the orifice. Seen that WAY too many times.
IDK if it would work for this system, but over here on larger systems we have an oil recovery cycle, never really studied it but from first glance they have a bypass on the TX with a solenoid, the basic idea is to get full flow with no evaporator restriction, obviously no cooling but the speed and volume of refrigerant going around the system picks up the oil. They also have a huge u-trap above the compressor to then get the oil back out I assume. Like I said, this is probably no help, but food for thought maybe.
Refrigerant piping and oil return is the least understood and overlooked part of refrigeration, in my opinion. In the 35+ years I've been doing refrigeration, I can't tell you how many times I've gone on a call only to find no P-trap installed when the condensing unit is on the roof and the evaporator coil is downstairs. Regarding checking the compressor valves on a hermetic compressor, I just simply shut down the condensing unit and feel the suction line with my hand, along with watching the pressures. Many times, you can hear the valves whistling. I have rarely front-seated the suction service valve on any compressor. Hopefully, the owner changes out the system because it has definitely seen its better days. Thanks for the video!
did you replace it yet? was that top part all full of oil in the end and not flowin? idk how this stuff works for the most part but i'm interested to know how it turned out!
I might guess that all that moisture was pulled out of the air so there aren’t salts or minerals in it to conduct electricity. Or much less. Love the content!
That style of metal wire shelf will easily hold 300-500 Pounds. We used the big 2ftx8ft racks at a cooler re manufacturing facility to hold our warranty compressors until they were released to be recycled. We almost always had the three lower racks filled with 30-50 pound compressors. Probably one of the best portable shelf designs on the market.
Ive run into this issue before, changed the txv to no avail like you did. One thing i noticed was that the noise of the refrigerant thru the coil sounded restricted, and was getting an odd frost pattern like you. Pretty sure its still running like that on reduced capacity, they only have issues on their busiest days but the customer didnt approve further work as they were moving from that site. Sometimes it takes a few tries before you get it right, good luck explaining that to the customer tho.
if its only oil sludge eveporator coil, there is simple trick most of the time may success, mark the position of TXV superheat adjustment then fully open - bypass controles - run compressor - off liquid solonoid and pump down - when reach vacuum open solonoid and let some refrigerant pass and off solonoid again , do this purge continuelly few time, with vacuum support purging refrigerant will bring oil back to comepressor , if have oil sight glass in compressor can see oil level increase while this process.
When the doors propped open to load freezer turn your timer. Turns system off and fans so you don’t draw in moisture. The timer is so when your done loading up you don’t forget to turn the system back on.
Fyi 6'2" 205lb 55yo. Did restaurants in house hot/cold for 30yrs, now with an outside contractor, for 8yrs, we do mid-size retail. Use your 32' fiberglass extension ladder every day just for the hell of it.
It's really hard to have shorts with ice from condensation or water vapors since it doesn't have any minerals in it and it doesn't conduct electricity.
And as ice freezes, it pushes impurities out. Why ice made from an ice machine is much more pure that ice made in trays.
That's interesting and makes total sense, I wouldn't have thought of that.
I will add the caution; condensate from a furnace can be conductive due to an abundance of CO2
Well, that's only true if there's no metal in the vicinity which isn't the case here. Some of the metal will be picked up by the water and make it more conductive than pure water.
But for a real short you need either a high voltage, or you have very close connections. Just some water next to electricity with 1-2 cm to travel to the next ground, will have way too much resistance for a short.
Ice does conduct its just high resistance so not a short. Short is zero resistance so current go to infinity.
Still 6'7" and 300+ pounds doing restaurant refrigeration.
You'd be surprised what a Metro rack will hold.
😂😂😂
christ youre tall
Damn dude football didn’t work out or what lol stay safe.
I’m 5’11”. 280. 😳
@@rookierefrigeration4357 same height for me, but im hovering around 240-235 and slowly dropping (again, from 260+) :)
Ice tends to be "pure" water. Minerals that can act as electrolytes are pushed to the center as water freezes. Or as mentioned, water vapor will be pure also. That makes ice relatively non-conductive.
I think you do a great job with every job you show us. Always making sure the customer is happy. I really enjoy watching you teaching us. I looking to get into commercial hvac from apartment maintenance. I’m enjoying learning from you. Thank you sir for your time to teach us
The plugged strainer likely slowed refrigerant velocity. The slowed velocity aided in poor oil return. Correcting the problem with the valve might possibly allow the return of oil. Cycling the unit sevral times from operation to pump down likely would scavage the oil back to the compressor. Piping design might play a role but what you had there isnt uncommon piping from what ive seen although likely not the propper way. Id honestly do a few pump downs and let it run for a week or two and return to see if the problem possibly resolves its self. We never had thermal cameras back in the day and often were listening to the old timers wisdom. As you said in the video it is hard to know if its a feed issue or a oil log. Could also be trash in a capilary. Customers dont realize alot of out work can be guestimation based on experience or the data we obtain on site as you generally never run into the exact same install because its field fabricated unlike say a car built on a assembly line
Great response! I agree it may have not been long enough for the oil to return after correcting the dirty strainer.
Industrial Refrigeration always have traps -- even with the CU less than 10' above the evaporator. Rarely see commercial apps with a trap for oil return.
I'm missing something. How did you come to oil logging from ice build-up? Everybody is so excited about this "oil problem" and I see no direct causal relationship between stated problem and this diagnosis. Any help will be appreciated.
As a mechanic of 5 years, I can tell you, assembly line or not, the job is still NEVER the exact same due to several other factors and variables that come into play. Every vehicle has it's own story, no engine is ever given the same demand, and no vehicle goes through same places or terrains/conditions. Every damn year and model is a completely different design nearly. There is a design that the engineers have put in place for the HVAC system in every vehicle, they have to route everything to fit just right, that is true, but that does not make them impervious to imperfections, random mishaps, McGyvers/DIYers, untrained individuals, or poorly thought out engineering from turning them into just as much of a complex nightmare. The guy that takes his shit to the river is gonna have a lot more chances at stuck bolts/parts, broken bits/plastics, and unforeseeable obstacles than any vehicle that sat in an air conditioned garage most it's life. Automobiles are introduced to some of the most severe weathering conditions and demand. Much more severe than a stationary slab on the side of the building. No matter what, it's all hard work, and takes a lot of skill to be apart of.. Most of all, it ain't easy fixing things so that they not only last, but so that it doesn't happen again.. There are tricks to each trade that you aren't going to know unless you're apart of it, but it'd be nice to not see the trades be devalued by one another simply because they "think" the other trade is somehow easier, when they each require the same amount of time, effort, and devotion to be considered a "professional" at..
My diagnosis would be blockage in the system.. Causing a difference in pressure in the bottom part of the evaporator.. Hence all the icing. Restricted vein in the evaporator. Reciprocating compressor that's been changed before.. If the system wasn't properly cleared of debris the first time.. Makes sense that some bits could finally make their way to the Evaporator causing this condition. That is my guess based on my roundabout knowledge of automotive A/C systems..
a lot of good comments here although they all seem to be saying the same thing to me. you can mess with the plumbing all you want but you still end up having to reinstall the windows or replace it with Linux. Yeah I do Mac windows and Linux support same mantra. Lol you build up knowledge of the field and half the time you're guessing at what it can be or there's even where Crossing fields of knowledge helps make you thank what might be the problem from some unrelated thing.
This kind of difficult diagnosis videos are priceless to learn & avoid all the work it's done, for instance, swaping that TXV a saturday night. Can't express to you more gratitud to take the time to film that kind of things. Thank you very much Chris, I've become a better tech observing & thinking more and working less hard thank to your teachings.
our ac has been down for 2 days in 100+ heat, I appreciate guys in your line of work
LOVE when you get this call on a Friday at 6 and you say “when did you notice it?” “Oh last Tuesday” 😐
The most common comment that you hear from commercial refrigeration accounts or the other infamous one is you guy was here last week and did pm
Its always nice when your evaporator has a small leak and goes BOOM in the middle of the night!
Great use of the thermal camera. I love using it as a tool for diagnosing
I used mine in the same manner. I once used it on a Scotsman ice machine and clearly saw only half the cutting grid was working. That cutting wire doesn’t get too God awful hot.so it shows the difference nicely
Oil logging. I've had some success by pumping the system down, linking out the defrost & cooking the evap coil to lower the viscosity of the trapped oil. Then opening the receiver valve so that the sudden inrush of refrigerant pushes the runnier oil out of the evap. Repeat a few times & it should do the trick.
Now this was a good call for a lot of people out there on this video. Oil log is not something you see every day but it’s out there and can make you scratch your head!!! This is a teachable call even for me!!! I would have gone the same path but when I was first starting in the business this would have drove me crazy!!!
Down since the morning? But let’s call at 9:30? Lmao
Yep
@@HVACRVIDEOS its always like that.... i had the same thing... it failed the day before... (started acting up) lets call at 4:30pm on a friday so Thursday Afternoon till Friday 4:30..... SMH LOL!! that Compressor AVA 2490 its Heavy Noisey BUT its a work horse
God it’s always that way!! I’d rather them not tell me it’s been down all day because makes me soo angry sometimes.
Right ? Must not have had too much expensive product in the freezer. But, I have worked (I am a chef) for owners that hope for a miracle that it will straighten itself out. I have always been a huge fan of preventive maintenance. You see frost... I call "The Guy". If you were on the East Coast, you'd be "The Guy" that I'd call. Damn, you're so thorough.
Yep, night shift attitude: I'm at work so why aren't you?
Your method is the same approach I would have taken. I disagree the coil is oil logged conclusion just yet.
There are 2 other points I would consider to further evaluate before going with oil logged.
R502 system originally. Now r404 compressor in a 502 condenser coil. R404 needs a larger condenser coil by design. r404 cannot be a direct drop in for r502. Your SUBCOOLING was low at 3 degrees in my opinion, usually 8 to 10 degrees is what I see even with a receiver. So I'm wondering if your liquid is not subcooled enough and flashing off before the distributor.
An evaporator 1/2 colder on bottom makes me also consider a second problem, your nozzle could be oversized. Liquid and vapor separate, based on density, liquid bottom half of coil and vapor top half.
This coil frost pattern problem could have been around for a long time.
Absolutely no idea how I ended up here
LOL
But I watched the whole vid
You are on the right path! If your customers got a solid 20 years from a unit they shouldn't expect much more! If you repair the evaporator coil tomorrow it may be the roof unit! You have given the best advice.
im allways amazed that your electronics are so open and fly wired.
In germany we have to put every electric connection inside wireboxes and such so they arent open
Are the Germans worried about a new Hitler showing up if the electrical are out?
@@GoatzombieBubba its the same in canada, yall are just the wild west down there
Well, that's the reason why fire insurances in Germany are way lower ;P
Just an example: You cannot drill a hole thru a wall and stick some pipe or some wire thru it.
You need to have it sealed against fire breakthrough with special mortar.
David der Kabauter its legal to have wire nuts connection inside equipment. Equipment cover is a box so no additional box need. Same as canada i dont know what u guys talking about. You guys have different NEC code book?
I think you nailed it when you mentioned that it used to be 502. They likely never attempted to blow out the evap and the oils mixed and fouled up over time. Probably turning wax like. I’d cut a couple sections out see what comes out.
brandon thermal image which one are you using I’m looking in to buying one
I have no idea why TH-cam suggested one of your videos to me a few weeks back, but I've been hooked since. Pure relaxing cozy content.
Appreciate how thurough you are. I've learned a ton from your videos.
I've been doing hvac for 5 years, and just started doing refrigeration a year ago. Keep it up!!! Thanks!!!!
It’s hard to tell how much oil is in a system with the hermetic compressor unless it has A site glass in the compressor. But you’re probably right the oil my graded from the previous compressor and there’s probably too much oil in the system. Great analysis!
I had an emergency service call at a chick fil a about a week ago. The manager told me “The freezer has been temping around 10 to 15 degrees for like three weeks but we were concerned today because the temp has been above 18 degrees and we can’t allow it to get too warm” lol this took place on a Thursday night around 8 pm!
I dont have any knowledge or experience with HVAC nor am I looking for a career in HVAC but these videos are awesome to watch. Its the "fix it" bug in me that keeps me watching lol
Wow. I'm having flashbacks. I studied refrigeration and air conditioning in a good JC vocational program, right before I joined the Air Force in 1983. I then was trained at the Air Force's civil engineering refrigeration and air conditioning technical school at Wichita Falls Texas. Everything you're discussing is coming back to me. You are very good at describing systems, sharing your troubleshooting process, and also teaching the overall mindset you have to put yourself in, if you are going to really fix a problem. You are dead on about how important it is to be thorough and honest with customers. It is not easy especially when we accidentally screw something up (as we all do). It still pays off, because you gain trust. If you haven't already done so, you should consider looking at being an instructor somewhere.
always makes my day seeing hvacr posted another video
Nice work Chris, You went for the least expensive option for your customer, Oil logging is not worth the repair Because you could have had bad components due to oil loss and now your on the hook, NOTHING GETS PAST YOU AWESOME STUFF THANKS FOR SHARING
Videos like this make me happy I only work on vehicles in my driveway LOL. However a lot of respect goes out to you guys who deal will all of these issues so that we can have a comfy life at the restaurants and places we visit. The amount of Knowledge and Experience that goes into being an industrial HVACR Tech is amazing. My hats off to you guys! Thanks for sharing. Best Wishes & Blessings. Keith Noneya
Reminds me of the 3 dr rif with the cap tube I spoke with you about. I ended up going back, replaced the cap tube again, drilled there accumulator in there evap coil, got some oil out, restarted it and still had low suction pressure compared to what I'm used to. Total waste of time, so I agree it's time for a new evap coil. It could also have a little bit of a restriction in the distribution tubes. Who knows. Total guessing game at times, good video👍👍
Just stumbled onto your channel. Your a pro man I’m learning a lot for you thank you man.
TH-cam recommended is weird... But I don't regret watching at all
love it mate. youre well setup and so thorough with your inspections! Im in AC and sometimes need to dive into mid temp + low temp and it throws me off at times. You are an excellent methodical explainer
Brilliant, just brilliant. That oil investigation video would be awesome.
I mean 27 years, they got their money's worth. Also not what I'd consider being proactive in taking care of their equipment
If it ain't broke dont fix it. I'd rather a 93 over what they make today. The newer stuff is made to break
Maybe you have a nozzle between the TXV and the refrigerant distributor Look up inside for that little disk
Awesome videos. Thanks
Love your videos! I share your link with newer techs
Water is actually a lousy conductor, and ice from condensate is basically distilled water. It's all the contaminants (like salt) that water can pick up and dissolve that makes it conductive.
Not an HVACR by trade, but have done my own residential stuff while buying a fixer-upper. I found your videos through related searches and got addicted. The way you diagnose and work these issues is fantastic. If I was in the need of a tradesman of any kind, I truly hope I get one that is like-minded to you. Customers emotions can be a unique thing, but your work flow is always in their best interests.
I work as a locksmith and I can’t tell you how many times someone realizes their issue Friday morning at 7 but waits until 11:30pm to call in an emergency because they “can’t secure the store.” Then sometimes I’ll go out there and it’ll be something stupid like a back door alarm that has NOTHING to do with securing the door. (Passive alarm to alert when the door is opened)
Thank you so much for this information.,could replace just the evaporator coil?
I found this video very interesting! I have an understanding of automotive A/C systems, went to school for that, and I've been thinking of going back to school for commercial HVAC.
I watch every one of your videos until the end. I do the same exact jobs you do, damn near daily.
Everything you say makes sense. You are a super tech. Have a great one. Thanks for the videos. Very instructional.
Great video! Please make a follow up vid if you end up replacing the equipment! I definitely learned something new today. Thanks as always.
A year later... did you replace the system? And did you find oil in the evap? I didn’t see a link to any updates in the description. Thanks!
This was a great educational episode !
Your videos are awesome! Thank you!
Why is this on my recommended lol
Whats worse... I'm probably going to watch it anyways... And start getting recommendations on other similar videos... Next thing you know, I want to be a freezer technician...
I am also confused why it is showing
This and a video of a man declogging a pipe in a lake appeared on my recommendation
@@timslocum145 I got that one too. Have to admit, I watched it.
@@BobWiersema lol. so did I for a few minutes then it got boring
I think your diagnosis is on the money. Yes time for a new system. As usual great work Chris!
Use Blue Leak Lock on the flares ! 👍
Thanks for this video. Yes its difficult to flush out the oil from the evaporator ,since u mentioned P/U traps. Could u pls, show us how the piping could be done for better oil return.also with a system that has multiple evaporator s,connected to a single condensing unit. Lastly what about an oil seperator being used. Thanks.
Good job dude way to go look at the whole picture good synopsis good troubleshooting
Thanks for the great information on the video, you are so smart !
I appreciate.
you put a lot making this video.
Great work ! Finally getting caught up on your videos, work has been hectic latley
Hello, I enjoy your videos, as I used to be in the trade. I’ve seen this one before- when you had the system running, look at where your frost starts- it doesn’t start at the valve, but at the distributor. I used to have to play around with the distributor sizes to get it right on retrofits or old mismatched equipment. Ive even drilled some out the next size up. The literature will tell you the size for given refrigerant. (Although its just a guide)
That being said, when the box is down to temperature, that is when you look at your pattern. Too large a orifice, the refrigerant doesn't have enough velocity to shoot through the tubes evenly. Midway and up, the coil is dry. Too small of an orifice will feed evenly, but the superheat will be way too high for oil return and performance. Gut instinct tells me it is a bit too large, but I don't know how cold the box was when you showed the system running.
Sometimes you can get the oil out by flooding the evaporator. Drop the bulb in hot water and let'er rip. Obviously be careful with the compressor so you don't flood that too. I think it's less likely that it's a distributor or capillary problem owing to the pattern of frost. If one or two loops had problems, sure. But we're frosting up more in the bottom and less and less towards the top. Another thing, but i don't really see how it would be happening in this case, is an air flow issue. I experienced this when working on Liebert units in data centers. They had a little plate on the back of the coil presumably to hinder the air stream from blowing condensation out of the drain pan, but it also had the adverse effect that the lowermost loops would have the air flow restricted, thus causing the expansion valve to close and the upper loops being starved of refrigerant. Very difficult to get adjusted. In time we just got rid of those little plates and lo and behold we could get the evap pressure up significantly and it was suddenly a bliss to adjust the valves.
The box has been down since this morning!!! Just another SNAFU!!
If that riser is less than 3 feet a trap isn’t required, but I would still reverse trap the top side to prevent oil draining back to the evaporator from above. If it’s greater than 10’, use a velocity riser.
i had a call for a unit flooding really hard back to unit.coil had some frost on it not enough to restrict air flow.what i found was a coil not flooded,but still liquid was coming back to compressor.the coax heat exchanger in the case had broken internally liquid wasn t going through txv. but dumping directly into suction line back to compressor.by passed liquid line and that solved my oil failure issues.
Great great video this is/should be one of ur best videos and u have alot , but I said dat Because this is not something u run into often and the lesson to be learned from this is priceless..great video Chris.
I always was told, when the compressor is above the coils, you put in a ptrap. After hundreds of service calls, I very seldom see them. I prefer to put service ports in the box, so I can check pressures and pump downs, without hauling everything onto the roof, we have snow to deal with...last but not least. When you replaced the TXV, you should have had oil come out...but since the compressor was replaced. It was old oil, and the TXV was replaced and the oil drained out from the prior work...
Thank you for sharing
Thanks for doing restaurant work so that I dont have to. 🤙
You raise a good point about measuring the oil charge. I’m just an apprentice but the oil logged evaporator diagnosis makes sense. John Tomczaks book has a small section on troubleshooting oil logged evaporators and one of the symptoms is unexplained compressor failures, especially more than one. The plugged strainer likely didn’t aid in oil return along with the missing P trap.
Low heat conduction from those bottom coil rows makes sense and explains the frosting. Just like low airflow.
Did you thermal image the distributor? Just thinking perhaps there was a restriction on one of the capillary tubes. They all looked pretty uniform in the video though.
Thanks for a great video! Always learning something.
Have seen pipes crushed flat due to ice in coils which mess up the flow. Also seen distributors plugged, especially on systems that have been converted from mineral oil.
Nice find in market you find oil problems alot... Some similar to this... Good move playing all the cards you have
I just had to fix about 10 univents last week that hadn't been serviced since the late 60s. They hadn't worked since the 80s but with covid the school department seems to think they'll help with ventilation (they have no fresh air intakes). And replacing isn't an option.
Idea, why not flush the lines when you find a plugged strainer which is evidence of improper prior service procedures?
Holy hell Bro, that’s an awesome find. I agree with you, just give the customer their best options and go from there. I think you did everything correct and good job.
You are the man I like your ideas I like your style
The bottom defrost coil is pulled away from the evap coil. Possibly having the bottom of the coil warmer will help oil logging by better heating the oil in the bottom of the coil. Push it back into the depression so that it now contacts the aluminum coil again and secure with ss wire tied to the evap tube. If you added a suction filter to the condensing unit then you'd have a port where you wanted it.
Always learn something new from your videos ! Thanks for your efforts, I Appreciate it!
Good diag.... distributor lines could be an issue, but now that you have restored refrigerant velocity, there's a good chance in a few weeks the oil finds its way "home"..
Chris there should be more mechanics like you in this business restaurant work is the toughest most guys will not do it
Good I have been through such challenges and at times feel like I don't know my work and it hard to explain to the customer. But thump rule from this video always tell the truth and let the customer decide
Just look at the frost pattern on the distributor. The plugged strainer would tell you the orifice in the distributor is plugged. Take it out and let the expansion valve do the work. It's also using a different refrigerant that the original. My bet is that they didn't change the orifice. Seen that WAY too many times.
Awesome video learned a lot how do you know how much oil is suppose to be in the compressor can you also explain flooding back
IDK if it would work for this system, but over here on larger systems we have an oil recovery cycle, never really studied it but from first glance they have a bypass on the TX with a solenoid, the basic idea is to get full flow with no evaporator restriction, obviously no cooling but the speed and volume of refrigerant going around the system picks up the oil. They also have a huge u-trap above the compressor to then get the oil back out I assume.
Like I said, this is probably no help, but food for thought maybe.
When there is that much ice, oil will be a problem. I use external heat to help move the oil from coils faster.
Question: Does your vacuum pump ever draw in the oil that is inside of the system?
Refrigerant piping and oil return is the least understood and overlooked part of refrigeration, in my opinion. In the 35+ years I've been doing refrigeration, I can't tell you how many times I've gone on a call only to find no P-trap installed when the condensing unit is on the roof and the evaporator coil is downstairs. Regarding checking the compressor valves on a hermetic compressor, I just simply shut down the condensing unit and feel the suction line with my hand, along with watching the pressures. Many times, you can hear the valves whistling. I have rarely front-seated the suction service valve on any compressor. Hopefully, the owner changes out the system because it has definitely seen its better days. Thanks for the video!
Could you have taken your torch to heat up the capillary tubes? Maybe the restriction was in those?
did you replace it yet? was that top part all full of oil in the end and not flowin? idk how this stuff works for the most part but i'm interested to know how it turned out!
I might guess that all that moisture was pulled out of the air so there aren’t salts or minerals in it to conduct electricity. Or much less.
Love the content!
I can’t wait for you to find out about the oil being trapped in that evaporator
What does a P-trap do in an refrigeration line?
Condensation is cold distilled water, virtually an insulator :), lack of shorts actually makes a whole lot of sense
That style of metal wire shelf will easily hold 300-500 Pounds. We used the big 2ftx8ft racks at a cooler re manufacturing facility to hold our warranty compressors until they were released to be recycled. We almost always had the three lower racks filled with 30-50 pound compressors. Probably one of the best portable shelf designs on the market.
If they do get new equipment. I would love to see a video on it and the old coil
Old school suggest to add some miniral oil to the system its connect better with the refrigerant and will circulate the oil back to the compressor
Enjoy your videos. Wish I lived in California I would take you up on the hiring offer
Ive run into this issue before, changed the txv to no avail like you did. One thing i noticed was that the noise of the refrigerant thru the coil sounded restricted, and was getting an odd frost pattern like you. Pretty sure its still running like that on reduced capacity, they only have issues on their busiest days but the customer didnt approve further work as they were moving from that site. Sometimes it takes a few tries before you get it right, good luck explaining that to the customer tho.
When I saw the thumbnail, I thought he would make the fan blades spin so fast that they would come off the motors. 😂😂 I think very differently haha
if its only oil sludge eveporator coil, there is simple trick most of the time may success,
mark the position of TXV superheat adjustment then fully open - bypass controles - run compressor - off liquid solonoid and pump down - when reach vacuum open solonoid and let some refrigerant pass and off solonoid again , do this purge continuelly few time,
with vacuum support purging refrigerant will bring oil back to comepressor , if have oil sight glass in compressor can see oil level increase while this process.
Did you change the evap motors? That would definitely be another reason to change the evaporator.
I am quite curious as to why there is a time switch on the coil itself.
When the doors propped open to load freezer turn your timer. Turns system off and fans so you don’t draw in moisture. The timer is so when your done loading up you don’t forget to turn the system back on.
Just recently subscribed, I enjoy your channel and all the effort you put into your video's. Please keep them coming.
Great very informative video. I just had one with a similar issue. Luckily for me it was only a bad fan motor
Fyi 6'2" 205lb 55yo. Did restaurants in house hot/cold for 30yrs, now with an outside contractor, for 8yrs, we do mid-size retail. Use your 32' fiberglass extension ladder every day just for the hell of it.