Almost an hour long video? YES! My baby boy was cheering while you were brazing. Hopefully, if he wants to go into the trades, he will continue to have that enjoyment. Good work, Chris!
Very much a "Compressors don't just die, they're murdered" situation imo. One bit of sand or a bad connection in the contactor and suddenly the compressor isn't getting the power it wants and it's not going to be happy. Contactor changeout as a preventative measure is just doing right by your customers. 👍 Watching from Australia, this stuff's fascinating. Made it to the end 😃.
Sand in contacts is a real problem. I have had this problem on light switches before, due to renovations happening at the same time the switches were being installed. Lesson learnt.
Wow i said I would not touch a/c s but I got a call one day from a place that uses 13 of these 3 compressor types units. The hvac guy says power problem. Turns out the condenser fan relay burnt. I fix it but this the only person that explains this stuff so well. A million tanx bro
Anyone who tells you Chris , that changing contactors is an over waste , THERE DEFINITELY GOT NO IDEA AND HAVE NO PLACE IN THIS TRADE !!!!!! I’ve seen the first hand experience of low voltage and no low voltage issues, especially miss diagnostic test , over looking. ‘ pitted ‘. Burn’t contactor points , working normally they will 100% wear out and I’ve personally changed soooo many , low voltage and uneven load and phase will definitely cause. ‘ Brown - out ‘ burnt outs to occur , and house keeping has saved my clients and myself to call outs a good 40% on cooling tower fan units and especially compressor prematurely failing . It’s the basic rookie test of finding back to basics of diagnosing and testing ,mostly over looked and like your self , finding why, because , it’s the most important instead of just r & r , your statement is beyond true and I’m sure many , many , many , repeat repairs by air - con techs have gone to the same repair , more than once or replaced a new compressor to only return weeks or days later with another fault that was over looked !!! Well done and once again thanks for posting Chris, safe travels 😊 and Godbless 😊 , and I’ve watched the video , from start to end !!!
This is insane, the condition this equipment or people operate in. I live in Wyoming, We "might" have temps in the 90's 3 weeks out of the year. AC might run 3 months or 4 months out of the year. But our furnaces run 9 months out of the year. Really like you channel. Ted Cook "anti DIY HVAC gave you a shout out. You're really knowledgeable of your trade. Great workmanship and ethics. Until watching your channel, didn't realize how many of us take the contacts for granted.
I’ve been watching for about a year and a half. My friend/coworker that I respect and go to for guidance recommended you. I have recommended the videos to multiple co workers as well. I have learned a great deal, I had 20ish years in residential before coming to commercial.
Just wanted to say you are a troubleshooting Master! I have learned so much from your videos and I very much enjoy watching through everything, always learn something new! I’m 3 years in to the hvac trade and barely started commercial a year ago and your videos have helped me so much with troubleshooting commercial equipment, thank you sir.
This job like many jobs is about CYA ( cover your a** ). You perform "big picture diagnosis" to cover the customer, to cover yourself and your company. You provide solutions to all problems found and let the customer choose what they want to do....as Chris stated. It the best, professional and proper way to be a quality tech. The money isn't ours to spend. You handled that in every aspect like a true pro Chris......job well done......I'd hire you 😁😆😄
Thank you so much for showing the testing to ground immediately. I never learned that until this video. 2 yrs into the trade and I learned more with your videos and other technicians videos. Please continue I'm now following you like a hawk!
I absolutely appreciate the time you take to be thorough on your jobs. I started watching your channel about 2yrs ago already- and recently I was able to land a position with a Commercial HVACR business- but I've learned so much just by watching your trouble shooting methods but also, I'm beginning to understand the mentality of "take the extra 15mins to check on something or to do a task", which prevents so many issues down the road. I'm from Central Texas and the work I come to find is simply laziness. Love the videos, you're thinking and attitude, stay cool and be safe!
I really can't wait to keep sharing your channel! Been a sub for a while, and i must say you are simply the best! Your ability to explain every step you do plus your accountability to be honest, sets you apart from every other tech that is in the same trade. Thanks so much!
I miss some of your videos, so I'm playing catch up. I see the outside temp you work in and I feel your PAIN. I was a jet engine tech for the j-79 which was on the older C-130'S. There are many times in Arkansas summer when the temp on a wing can reach 105 to 120 deg. Believe it or not we had to wear coveralls and special gloves just to handle a prop or engine during a change and that can take between 6 and 8 hrs. Stay safe and don't go to long in the heat, it will bite you hard.
I rebuild semi hermetic compressors for a living. Its clear when you turn the rotor on the table that shine on one side indicates the rotor was rubbing against the stator. That will cause a burn out eventually.
You do amazing videos!! I always look forward to watching them. Learned a bunch of content from you. Watched the entire video from the beginning!! Be safe
Chris, in this day of corporate cost cutting by employers, talking about total man hours on jobs like this would be really useful to techs old and new. Other than that I love your videos and appreciate you sharing your knowledge, especially with the failure analysis stuff, which is my first love from my Navy ET days. That root cause stuff and the curiosity behind it truly is what makes great techs. 🎉 Thank you!
Keep up the good work I think you got the best hvac channel on RUclips. You do a great job explaining your thought, & execution process on things. I am a residential/ commercial tech that's disabled with multiple sclerosis. I really loved the trade, & videos like yours still makes me feel apart of the trade still.
Made it to the end! I didn't even realize it was 58 minutes until halfway through - quite the journey. I appreciate your thoroughness and eye for preventative maintenance - contactors included. Thinking about future potential trouble helps in other fields, too - including software engineering, what I'm pursuing.
Chris, Awesome video and diagnosis. I like how your approach is very carefully planned and cautious. I have a story on a 40ton McQuay RTU. The unit had two circuits with 4 stages of cooling. 1st stage compressor had one blown fuse feeding compressor contactor. Checked all basics before checking compressor. Compressor checked out ( electrically) using Copeland mobile app , ohms were good in spec and no shorts to ground. Very handy app. So at this point I decided nothing left to do but to put fuse in and check under power. WELL.... the compressor had a mechanical problem and broke. Blew compressor terminal plug out like it was hit with a shotgun buckshot with a massive arch of quick flash fire. It immediately went out. Blew the refrigerant charge out. Thank God I was like 8ft back away from unit when it came on. I immediately killed the disconnect and went off the roof to change my underwear..... scary stuff. I found out later the TXV was completely plugged and bad. It was banging off high pressure control and would reset later to continue to do it again. Always use caution and be careful cause usually there is a reason something broke.....
I’m going to tech school next year and I chose hvac as one of my trades and I honestly am so excited to learn about this stuff, your videos teach me a lot!
Awesome bud, I’m going live on RUclips this evening 7/25/22 @ 5:PM (pacific) to answer questions from the live chat, emails and RUclips comments, come over and check it out…or not ruclips.net/video/5HS0Ag5fTes/видео.html
Great teardown and analysis of the compressor failure. I do agree, I believe the blowing sand seems the root cause of the contactor failure and thus, compressor failure. My thoughts: Contactor contacts are accessible to the enviromentals, so sand contaminated them. Because the 3rd stage is used less then the 2nd and 1st stage, the contacts in the 3rd stage contactor remain open overall longer, and had more time to have sand/dirt build up. One or more phases may have become open, or a resistance developed in the contacts of the contactor and resulted in a low voltage condition. Eventually the overload in the compressor will have cut. Once the overload reset, and stage 3 call initiates, the process repeated with each time degrading the overload and windings. Eventually the overload may have failed stuck on or shorted, causing the compressor winding to heat up until the winding varnish failed and a short to ground developed and tripped the breaker. Perhaps the winding varnish failed first. Thats my educated guess. The contactor is def the Achilles heel. Makes me ponder how great it would be to have something monitoring the 3 phase power to the compressor itself, in addition to the normal protections. Such microprocessor powered monitoring could disable the stage much faster, throw an error code and alert for service call. Perhaps such already exists (I never messed with large systems like that). Your maint PM plan on regularly changing the contactors is a great idea. That is much less expensive then a catastrophic failure and extended unexpected down time vs a lesser planned down time.
I love your big picture thing. Get in there and LOOK for problems or potential problems and bring it up to the customer. A nearly hour long video and I watched it all. I love your work.
I believe that compressor fail due to refrigerant in liquid state flushed the oil .a mechanical issue ending in an electrical failure.part of the problem loose blower motor belt you corrected the problem. Congratulations I enjoyed your videos. Thanks again
Seems to me that changing contactors to sealed EP type (e.g. Class I Div 1/2) would be more cost effective than routine replacements. Just a thought! Another great video, Chris!
I will discuss this on my livestream this evening 7/25/22 @ 5:PM (pacific) on RUclips come over and check it out… or not ruclips.net/video/5HS0Ag5fTes/видео.html
Contactors are a fraction of the cost of a new compressor. Hence I am with Chris on this one. I will do the same if I was in this position, and indeed when I used to design stuff like this I recommended to the installers that they do the same, to avoid myself having been called out to answer for product failure and it has saved me from at least two lawsuits.
thank you for your videos. one of the reasons i watch them (aside from pure learning, which there is alot of) is at the end you sometimes you dismantle the components, in this case a compressor and contactor. you then explain how they work, and give excellent insight as to why they failed. i appreciate all you do to help educate myself and all the other folks who pursue this never ending industry of woes.
100% agree with not charging anymore on the split. You probably have a TXV that’s over feeding right now because it’s so hot. And don’t get me started on those wires sticking out the top. I’ve seen way too many dry rot and short. I always wrap my exposed wires in electrical tape. Trevor Matthews is an awesome asset! Great guy and great knowledge. Thank you, sir, for your dedication to the channel and and the industry!!
Thank you so much for making all those videos, the autopsy and and the discussion part. I only recently learned that the initial intent was to release those videos internally for your employees, so again, thanks for letting all of us take part in what you're doing :D Wish I had your beard!
Instead of replacing all the contactors every PM you can sell them ICM450 phase monitors. This will prevent phase imbalance and low voltage problems. it will save the compressors.
I just diagnosed a compressor short in a household portable dehumidifier. They used in in an industrial setting with fine dust and never cleaned the stuff out, the whole thing was full. So it was an overheating issue. The thermal switch probably saved it a hundred times already, but it eventually welded shut and failed to protect the last time. Probably. All I want to say is, there is all that electronics control, why no self-diagnostic for overheat too? When there are overheat events, possibly with increasing frequency, then after the n-th one, shut the system dowm with an error code as an early warning. There is no use of that auto-resetting thermal switch, if no one is getting notified that it is happening. Just as an example that similar thing already exists: in safety-critical industrial systems, a lot of stuff, for example contactors, sensors, etc are duplicated, in case if one fails the other will still do the job. BUT! If there would be no notfication about it, then the system would become as unsafe as with just one contactor or sensor or anything. For this exact reason, the system (safety relays) monitor everything that is duplicated, and when the paired things does not match state, it always disables the system (into a known good, safe state) and/or notify staff about the degraded safety, depending on how critical is to keep operating.
There was a blank plate in that location at once. Only supposed to remove it if you're installing an electric heat strip though. Great video as always!
Great video, very entertaining! This case specifically makes me wonder why the manufacturers of these AC units don't put a dustproof, well insulated box for the contactors to be in. The failure rate could go down drastically, as well as repair costs (especially in this case). What I mean is that it could lower the rate of catastrophical failure, like this one where it possibly single-phased the compressor, destroying it, not regular failure, like for example a compressor wearing out over time naturally. This applies to defrost clocks as well. Delicate parts are exposed to the outside influences when they can be very simply protected from them. Just a thought, feel free to correct me if there is a reason it's not done this way, maybe it's not up to code or something, idk. :D Have a wonderful day everyone!
That 5 ton should have a cover plate. They probably took it off for a better hand grip during install and never put it back in. We almost always install heat strips but I don't imagine you need them in so cal!
@@garousata4261 it's for emergency heat and they are usually set to kick on when the temp is more than 3 degrees below what heat is set to. In the south it is only used when it gets really cold or if the condensing unit stops working.
I work and live in the high desert, and that sand is no joke. A couple months ago I did a spring PM on a residential AC. I removed a Home Depot bucket’s worth of sand out of the condensing unit and then some. I make a point of getting all the dirt and sand out of condensing units before hosing down the coil, otherwise it will turn into a huge muddy mess and becomes a time consuming headache. I learned this the hard way last summer. I’ve also been making a point lately to take apart fan motors that I’ve replaced to see what went wrong in them when I have the time for it, for a learning experience and out of shear curiosity. I had one blower motor that I could hear arcing in the attic while I was at the Tstat, just before it tripped the breaker. Took that one apart, it appeared that the bearings failed and caused the rotor to make contact with the stator. The windings were a blackened charred mess as well.
I respect the integrity to which you do your wk. Your customers receive the best return for their $ spent. The BIG PICTURE battle cry has helped me in my own job to keep me striving to move further in diagnosis. We all need the reminder when things get summer crazy out here. God bless you and family, I appreciate all you have done and are doing!
Maybe Try sealing contactor so sand can't get in. Do Quality work tighten wires to spec. reduce contact resistance and overheating. Replacing cover and panels to prevent Sun UV deterioration and sand infiltration. These thing may help. All the best to you. Thanks for the video.
I like your videos. Very professional. Worked on identical unit last week. 2nd stage compressor shorted internally. Only difference was it blew out the L2 pin and the entire refrigerant and oil charge. Was a serious mess.
I love the music around the 30 min mark. Was half expecting the camera to turn and show John & Ponch riding up the road, turning on lights and sirens 🚨 and then nailing the throttle!!
Always love your vids always keep Me sharp and on game whenever im working or air conditioning I’ve done learned a lot from your vids made me definitely a better at all this stuff keeps me motivated and just want to show appreciation for your vids because i do Understand that it takes time for you do so I understand everything you say in your vids super educated and clearly knowledgeable about refrigeration and air conditioning and some other interesting things I’ve seen yah done there but yeah you show me a-lot in just a video it’s amazing to me always waiting for the next one can’t wait to Start my own videos but yeah much respect and love man
Excelente contenido, mi rubro es la refrigeración y aire acondicionado domésticos en Argentina desde hace unos 9 años, y en mi opinión sobran los motivos para reemplazar contactores mucho más en éstas condiciones, sin dar demasiadas explicaciones a quien diga que no es necesario, es porque evita mayores reparaciones y costos asociados, podrías también hacer un video para orientarnos sobre cómo y dónde cortar compresores sería genial ver eso, excelente tu trabajo y realización del contenido!
On changing contactors: The same situation has presented itself THOUSANDS of times during my career in electronics. Relays, contactors, and the switches. They fail, and cause issues LIKE THIS! HVAC, gate automation, shutter door automation, you name it I've seen it all. It is a cheap component that can be replaced and prevent issues happening later.
Could you double up contactors? I.e. give the electricity a redundant second path in case sand gets into one of that pair of contactors and blocks it from making a proper connection?
@@Pystro No two contactors are the same, their speed to make/break will be different across the same batch, therefore one set will burn contacts and the other set will be hardly used and vice-versa. We tried this approach long ago in the early 2000s with gate automation- the solution was full VFD / H-bridge
@@thesoniczone Well, in my proposed use case the intent is to avoid single phasing (or other consequences of 1 of the 3 contacts staying open), which I would guess would then only happen for half a second at a time or so which won't burn out a compressor. (No idea if that's true, though. I'm not an electrician.) The inspiration was that the contactors are dirt cheap compared to the equipment they are controlling, so you can avoid using more of them (both in terms of frequent replacing and in terms of requiring 2 of them to fail simultaneously before that damage can propagate to other components). Secondly, if there's a grain of sand on a contact face, the current could go through the other contactor (while both contacts are "closed"), and thus avoiding arcs of electricity persisting around that grain long enough that it gets welded into the contact face - unless the contact face with the sand grain is the slower one to open, but even then you'd only get a transient arc. But I agree. In these conditions some silicon-based solution would be preferable.
@@Pystro I was an engineer for 14 years but I traded it for a career in software dev. I was working at one body shop (software development house) around 2016 and the A/C failed, yet it had electronics to detect single phasing, and it displayed the error code which we looked up before calling a service technician. We indeed did single phase and because of a wire that burnt off (YELLOW PHASE). So it is possible to detect these conditions electronically- I don't understand why they don't do this though on these commercial units.
Saw belt deflection being tested. Wanted to share: the other day, someone taught me a formula for belt tension. 1/64 per inch on belt for deflection. So an example: an ax-64 belt should have 1 inch of deflection. An ax-32 belt should have 1/2" deflection... And so on. Hope it helps someone...
Probably 3rd stage contactor damaged because of it works less and contacts are open most part of time, sand settles between contacts. Meanwhile 1st & 2nd stage contacts are closed and not so damaged. IMHO. Cool work and investigation 🔎!
Good tip on keeping your grinder to shallow cuts, one to keep debris out, but also two it can preserve the life of a cutting wheel. In my experience plunging the wheel wears it out so much faster, especially since little twists can wear out the faces of the disk making them just disintegrate
Always make it to the end! I've said forever that I'd love to be able to put a motor starter/contactor cabinet down in the building. It would take a ton of wiring from each unit but if you could put all the VFDs and contactors inside the building, it would certainly prevent a lot of failures.
They sell sealed contactors that have enough of a cover to keep sand out. And the unit could be designed to keep it's own control electronics cool even if it's mounted outside - it's a f'ing box that literally makes COLD AIR. My first thought is "mount the control and VFD in the conditioned air space", but then "what if the VFD blows up? All that crap gets sucked inside - that's bad" - ok fine. Idea #2, mount the control and VFD on a heatsink that sits on the cold air side of the unit, but the parts themselves are still on the outside side. These things are just designed to be cheap, and fail. They could also include current monitoring on every compressor and fan motor in this thing, and detect failures long before they actually happen, and for not very much BOM cost, but they don't do that either.
I will discuss this on my livestream this evening 7/25/22 @ 5:PM (pacific) on RUclips come over and check it out… or not ruclips.net/video/5HS0Ag5fTes/видео.html
Just so you know, some (usually older) breaker panels don't have isolation for the connection points where the wires will connect to the panel for the individual, breakers so it can be risky to work inside the panel (ie replacing the wires) as you can be very close to live busbars or connections. That's maybe why they needed to shut the whole building (panel) down.
Hey buddy I like your style you always look out for the next guy coming up I've been watching your videos for a couple years now and I watched them all to the end you make it sound exciting you have to love what you're doing I tell the young kids today you have to love what you're doing I can tell you love your job I'm the same way keep up the good work Buddy
I think your hypothesis is correct. I know what sand does to your relays and contactors. Sand is a very good isolator. So it is very easy to get one phase missing situation which burns your motor. That is why motor protection circuit breakers are recommended.
Great video! Liked your call on blowing system with nitrogen, checking oil and looking at the bigger picture and changing all compressor contactors. Hard to find techs who analyze and solve. Also enjoyed the compressor autopsy. Gave us a view of something we normally wouldn’t get to see and learn from. Thanks for taking the time and energy in sharing quality info! Btw, that heat strip opening in that carrier fcu is supposed to be blanked off if heat strip is not installed. A bit of supply air short cycles back to negative section. Carrier has been getting away with this forever! Ok done ranting! Keep em coming!
I'd consider to use a big lathe (works for round compressors, not oval) or a milling machine to cut the compressor open. But you use what you have at hand.
This is why I put phase monitors on all my equipment...needed or not. Condom principle...better to have and not need than need and not have...one day it will safe thousands if not more...
The armature looks like it was contacting the steel laminations of the field windings; my guess is that the lower motor bearing failed and the drag caused by the bearing failure caused the motor to be incinerated
I’m surprised you don’t have a molecular transformator for 410a recovery in that heat! I just got one to recover about 30lbs of 410a for a compressor change. It was high 90s in the Michigan summer and that thing made a HUGE difference in recovery time. Just dropped it in a bucket of ice water and let that machine suck. Never got over 300psi in the tank.
I will discuss this on my livestream this evening on RUclips 8/1/22 @ 3:PM (pacific) come over and check it out ruclips.net/video/HSIOTgOXxV0/видео.html
The contactors looked like OEM, that is usually overlooked, and or ignored by most techs who come to do a hurry-up maintenance. Voltage Spikes in a building are real, could it be when the other unit had its problem with the wiring that this occurred ? As for the (2) Two condensing units blowing towards it ! most definitely an issue. Heat of compression cannot freely escape. Solution here is a deflector shield great video, really liked the time it took IE extra help lumping equipment.
EET here! Could have been a rub in the insulation of the magnet wire, happens from time to time when manufacturing motors and transformers. This kind of issue could be dormant for years, then one day the winding get shorted to another one and the motor gets oversaturated and overheats.
I had the same exact thing happened to me on the same exact unit. Third stage compressor went out, and going back through it and found it was single phased
I see quite a few comments indicating potential failure points on this compressor, I do want to add a few other electrical things that may have led to this. That contactor looks like it took a lot of heat on all three phases. Now it was already mentioned that the third stage is going to cut in and out far more than the others when it is operating, but that also started to make me think. You could have had single phasing, but you could have just had a plain case of low voltage. The overload looks like it also took a lot of heat due to the bluing I see. Now that could mean excess current flowing. A few electrical conditions that will cause excess current over a longer period of time would be single phasing, under-voltage, and even mechanical overload which was also mentioned in another comment regarding the rotor rubbing the stator. I think all of these factors (Single phasing included or not) lead to the burn out. The third stage activates when there is a heavy load during high heat, this is when the power grid is at high load meaning the potential of lower line voltages. Even if the voltage was in specification, you have the stator and rotor in contact with each other, this means slightly more time at locked rotor current and you could...at least in theory have failure to start and the overload cutting in and out a bit. If there were cases of single phasing this would be greatly amplified.
Washington state is in the 90s right now too. I’m so glad I have a 14,000BTU unit even if it only keeps my 500sqft apartment 70F since it’s on the 6th floor.
It’s easy to see someone else who is doing something wrong. It’s harder to do the same thing. The trick is learning how to control the grinding. Still it’s very informative to hear from your experience.
Made me laugh out loud when you were shaking those wires because I immediately thought of a situation where I did this and no problems and a day later I had to come back because AC wasn't working. I was like "what the heck?" go back up there check my wiring and it took about 15 minutes, but I found one broken wire about an inch below where I just stripped and put on a new wire nut.
if you are ok with running the compressor and cycling the overload protector on and off you can use the overloaded state to warm up the compressor so the gas will boil out of the oil and recover easier. metal flakes in the oil means you are well on the way to destroying the compressor and blocking up the txv/cap line and even radiator coils if they are like car radiators with small channels.
Almost an hour long video? YES! My baby boy was cheering while you were brazing. Hopefully, if he wants to go into the trades, he will continue to have that enjoyment. Good work, Chris!
Hopefully if he goes into the trades his first boss isn’t a scam artist or straight a hole.
Very much a "Compressors don't just die, they're murdered" situation imo.
One bit of sand or a bad connection in the contactor and suddenly the compressor isn't getting the power it wants and it's not going to be happy.
Contactor changeout as a preventative measure is just doing right by your customers. 👍
Watching from Australia, this stuff's fascinating. Made it to the end 😃.
Sand in contacts is a real problem. I have had this problem on light switches before, due to renovations happening at the same time the switches were being installed. Lesson learnt.
What's up , new hvac tech here ( 2 years ) , love your videos man !!! I'm gonna watch em' all for sure , keep going
Always change your contactor on 3 phase unit when you change the compressor.
Wow i said I would not touch a/c s but I got a call one day from a place that uses 13 of these 3 compressor types units. The hvac guy says power problem. Turns out the condenser fan relay burnt. I fix it but this the only person that explains this stuff so well. A million tanx bro
Anyone who tells you Chris , that changing contactors is an over waste , THERE DEFINITELY GOT NO IDEA AND HAVE NO PLACE IN THIS TRADE !!!!!! I’ve seen the first hand experience of low voltage and no low voltage issues, especially miss diagnostic test , over looking. ‘ pitted ‘. Burn’t contactor points , working normally they will 100% wear out and I’ve personally changed soooo many , low voltage and uneven load and phase will definitely cause. ‘ Brown - out ‘ burnt outs to occur , and house keeping has saved my clients and myself to call outs a good 40% on cooling tower fan units and especially compressor prematurely failing .
It’s the basic rookie test of finding back to basics of diagnosing and testing ,mostly over looked and like your self , finding why, because , it’s the most important instead of just r & r , your statement is beyond true and I’m sure many , many , many , repeat repairs by air - con techs have gone to the same repair , more than once or replaced a new compressor to only return weeks or days later with another fault that was over looked !!!
Well done and once again thanks for posting Chris, safe travels 😊 and Godbless 😊
, and I’ve watched the video , from start to end !!!
This is insane, the condition this equipment or people operate in. I live in Wyoming, We "might" have temps in the 90's 3 weeks out of the year. AC might run 3 months or 4 months out of the year. But our furnaces run 9 months out of the year. Really like you channel. Ted Cook "anti DIY HVAC gave you a shout out. You're really knowledgeable of your trade. Great workmanship and ethics. Until watching your channel, didn't realize how many of us take the contacts for granted.
I’ve been watching for about a year and a half. My friend/coworker that I respect and go to for guidance recommended you. I have recommended the videos to multiple co workers as well. I have learned a great deal, I had 20ish years in residential before coming to commercial.
It is my pleasure to watch a professional work.
Just wanted to say you are a troubleshooting Master! I have learned so much from your videos and I very much enjoy watching through everything, always learn something new! I’m 3 years in to the hvac trade and barely started commercial a year ago and your videos have helped me so much with troubleshooting commercial equipment, thank you sir.
Really digging the 80's montage music, it's like I'm learning how to type in 6th grade off a laserdisc all over again.
Always enjoy your videos. You have the heart of a teacher.
What about a clear box to enclose the contactor to extend the life in sandy conditions?
1h video? What a treat. Thanks, yum-yum.
I'm not an HVACR tech. But I'm an electro mechanical tech and like the electrical troubleshooting you do well. Keep up the great work!
This job like many jobs is about CYA ( cover your a** ). You perform "big picture diagnosis" to cover the customer, to cover yourself and your company. You provide solutions to all problems found and let the customer choose what they want to do....as Chris stated. It the best, professional and proper way to be a quality tech. The money isn't ours to spend. You handled that in every aspect like a true pro Chris......job well done......I'd hire you 😁😆😄
The closing words are so important to follow in this trade, be a technician, not a parts changer, figure out why it failed. 👏
Thank you so much for showing the testing to ground immediately. I never learned that until this video. 2 yrs into the trade and I learned more with your videos and other technicians videos. Please continue I'm now following you like a hawk!
I watch from beginning to end its great when you take them apart you have all kinds of awards
I appreciate the brazing montages and the effort put into it with the music and everything, really love watching them!
I absolutely appreciate the time you take to be thorough on your jobs. I started watching your channel about 2yrs ago already- and recently I was able to land a position with a Commercial HVACR business- but I've learned so much just by watching your trouble shooting methods but also, I'm beginning to understand the mentality of "take the extra 15mins to check on something or to do a task", which prevents so many issues down the road. I'm from Central Texas and the work I come to find is simply laziness. Love the videos, you're thinking and attitude, stay cool and be safe!
I really can't wait to keep sharing your channel! Been a sub for a while, and i must say you are simply the best! Your ability to explain every step you do plus your accountability to be honest, sets you apart from every other tech that is in the same trade. Thanks so much!
I miss some of your videos, so I'm playing catch up.
I see the outside temp you work in and I feel your PAIN. I was a jet engine tech for the j-79 which was on the older C-130'S.
There are many times in Arkansas summer when the temp on a wing can reach 105 to 120 deg. Believe it or not we had to wear coveralls and special gloves just to handle a prop or engine during a change and that can take between 6 and 8 hrs.
Stay safe and don't go to long in the heat, it will bite you hard.
I rebuild semi hermetic compressors for a living. Its clear when you turn the rotor on the table that shine on one side indicates the rotor was rubbing against the stator. That will cause a burn out eventually.
You do amazing videos!! I always look forward to watching them. Learned a bunch of content from you. Watched the entire video from the beginning!! Be safe
Chris, in this day of corporate cost cutting by employers, talking about total man hours on jobs like this would be really useful to techs old and new.
Other than that I love your videos and appreciate you sharing your knowledge, especially with the failure analysis stuff, which is my first love from my Navy ET days. That root cause stuff and the curiosity behind it truly is what makes great techs. 🎉 Thank you!
I had a great time taking apart our 34 hp recip low stage compressor after we oil slugged it. It was a great learning experience.
Keep up the good work I think you got the best hvac channel on RUclips. You do a great job explaining your thought, & execution process on things. I am a residential/ commercial tech that's disabled with multiple sclerosis. I really loved the trade, & videos like yours still makes me feel apart of the trade still.
Made it to the end! I didn't even realize it was 58 minutes until halfway through - quite the journey.
I appreciate your thoroughness and eye for preventative maintenance - contactors included. Thinking about future potential trouble helps in other fields, too - including software engineering, what I'm pursuing.
Loved the 80's/90's Sitcom music while Brazing LOL
Chris,
Awesome video and diagnosis. I like how your approach is very carefully planned and cautious. I have a story on a 40ton McQuay RTU. The unit had two circuits with 4 stages of cooling. 1st stage compressor had one blown fuse feeding compressor contactor. Checked all basics before checking compressor. Compressor checked out ( electrically) using Copeland mobile app , ohms were good in spec and no shorts to ground. Very handy app. So at this point I decided nothing left to do but to put fuse in and check under power. WELL.... the compressor had a mechanical problem and broke. Blew compressor terminal plug out like it was hit with a shotgun buckshot with a massive arch of quick flash fire. It immediately went out. Blew the refrigerant charge out. Thank God I was like 8ft back away from unit when it came on. I immediately killed the disconnect and went off the roof to change my underwear..... scary stuff.
I found out later the TXV was completely plugged and bad. It was banging off high pressure control and would reset later to continue to do it again.
Always use caution and be careful cause usually there is a reason something broke.....
As much as I watch these videos, the more I admire who do this job. Stuff is way more complicated than I ever could have imagined
Made it to the end, love listening to your job debriefings.
I’m going to tech school next year and I chose hvac as one of my trades and I honestly am so excited to learn about this stuff, your videos teach me a lot!
Awesome bud, I’m going live on RUclips this evening 7/25/22 @ 5:PM (pacific) to answer questions from the live chat, emails and RUclips comments, come over and check it out…or not ruclips.net/video/5HS0Ag5fTes/видео.html
Recommend contactors to be installed inside closures to protect from sand damage.
You can still service them
Great teardown and analysis of the compressor failure. I do agree, I believe the blowing sand seems the root cause of the contactor failure and thus, compressor failure.
My thoughts:
Contactor contacts are accessible to the enviromentals, so sand contaminated them. Because the 3rd stage is used less then the 2nd and 1st stage, the contacts in the 3rd stage contactor remain open overall longer, and had more time to have sand/dirt build up. One or more phases may have become open, or a resistance developed in the contacts of the contactor and resulted in a low voltage condition. Eventually the overload in the compressor will have cut. Once the overload reset, and stage 3 call initiates, the process repeated with each time degrading the overload and windings. Eventually the overload may have failed stuck on or shorted, causing the compressor winding to heat up until the winding varnish failed and a short to ground developed and tripped the breaker. Perhaps the winding varnish failed first.
Thats my educated guess. The contactor is def the Achilles heel. Makes me ponder how great it would be to have something monitoring the 3 phase power to the compressor itself, in addition to the normal protections. Such microprocessor powered monitoring could disable the stage much faster, throw an error code and alert for service call. Perhaps such already exists (I never messed with large systems like that).
Your maint PM plan on regularly changing the contactors is a great idea. That is much less expensive then a catastrophic failure and extended unexpected down time vs a lesser planned down time.
No Idea how I ended up here but DAMN it was interesting, this dude knows his craft.
I love your big picture thing. Get in there and LOOK for problems or potential problems and bring it up to the customer. A nearly hour long video and I watched it all. I love your work.
I believe that compressor fail due to refrigerant in liquid state flushed the oil .a mechanical issue ending in an electrical failure.part of the problem loose blower motor belt you corrected the problem. Congratulations I enjoyed your videos. Thanks again
Hi, it's awesome the work you do, I'm really happy to hear that the restaurant is getting properly cooled.
I always change contactors with a compressor.
You’re the most awesomeness HVAC guy in America
How's that boot taste?
Seems to me that changing contactors to sealed EP type (e.g. Class I Div 1/2) would be more cost effective than routine replacements. Just a thought! Another great video, Chris!
I will discuss this on my livestream this evening 7/25/22 @ 5:PM (pacific) on RUclips come over and check it out… or not ruclips.net/video/5HS0Ag5fTes/видео.html
Contactors are a fraction of the cost of a new compressor. Hence I am with Chris on this one. I will do the same if I was in this position, and indeed when I used to design stuff like this I recommended to the installers that they do the same, to avoid myself having been called out to answer for product failure and it has saved me from at least two lawsuits.
thank you for your videos. one of the reasons i watch them (aside from pure learning, which there is alot of) is at the end you sometimes you dismantle the components, in this case a compressor and contactor. you then explain how they work, and give excellent insight as to why they failed. i appreciate all you do to help educate myself and all the other folks who pursue this never ending industry of woes.
100% agree with not charging anymore on the split. You probably have a TXV that’s over feeding right now because it’s so hot. And don’t get me started on those wires sticking out the top. I’ve seen way too many dry rot and short. I always wrap my exposed wires in electrical tape.
Trevor Matthews is an awesome asset! Great guy and great knowledge.
Thank you, sir, for your dedication to the channel and and the industry!!
Thank you so much for making all those videos, the autopsy and and the discussion part. I only recently learned that the initial intent was to release those videos internally for your employees, so again, thanks for letting all of us take part in what you're doing :D Wish I had your beard!
Instead of replacing all the contactors every PM you can sell them
ICM450 phase monitors. This will prevent phase imbalance and low voltage problems. it will save the compressors.
I just diagnosed a compressor short in a household portable dehumidifier. They used in in an industrial setting with fine dust and never cleaned the stuff out, the whole thing was full. So it was an overheating issue. The thermal switch probably saved it a hundred times already, but it eventually welded shut and failed to protect the last time. Probably.
All I want to say is, there is all that electronics control, why no self-diagnostic for overheat too? When there are overheat events, possibly with increasing frequency, then after the n-th one, shut the system dowm with an error code as an early warning.
There is no use of that auto-resetting thermal switch, if no one is getting notified that it is happening.
Just as an example that similar thing already exists: in safety-critical industrial systems, a lot of stuff, for example contactors, sensors, etc are duplicated, in case if one fails the other will still do the job. BUT! If there would be no notfication about it, then the system would become as unsafe as with just one contactor or sensor or anything. For this exact reason, the system (safety relays) monitor everything that is duplicated, and when the paired things does not match state, it always disables the system (into a known good, safe state) and/or notify staff about the degraded safety, depending on how critical is to keep operating.
I agree with you.
Dirty micro channel and 410A= multiple head preassure trips could have caused contactor to stick and phase out compressor.
There was a blank plate in that location at once. Only supposed to remove it if you're installing an electric heat strip though. Great video as always!
Great video, very entertaining! This case specifically makes me wonder why the manufacturers of these AC units don't put a dustproof, well insulated box for the contactors to be in. The failure rate could go down drastically, as well as repair costs (especially in this case). What I mean is that it could lower the rate of catastrophical failure, like this one where it possibly single-phased the compressor, destroying it, not regular failure, like for example a compressor wearing out over time naturally. This applies to defrost clocks as well. Delicate parts are exposed to the outside influences when they can be very simply protected from them.
Just a thought, feel free to correct me if there is a reason it's not done this way, maybe it's not up to code or something, idk. :D
Have a wonderful day everyone!
That 5 ton should have a cover plate. They probably took it off for a better hand grip during install and never put it back in. We almost always install heat strips but I don't imagine you need them in so cal!
Why do you need heat strips in the frist place? That thing is an heat pump right? ( Or at least it should be....
@@garousata4261 it's for emergency heat and they are usually set to kick on when the temp is more than 3 degrees below what heat is set to. In the south it is only used when it gets really cold or if the condensing unit stops working.
I work and live in the high desert, and that sand is no joke. A couple months ago I did a spring PM on a residential AC. I removed a Home Depot bucket’s worth of sand out of the condensing unit and then some. I make a point of getting all the dirt and sand out of condensing units before hosing down the coil, otherwise it will turn into a huge muddy mess and becomes a time consuming headache. I learned this the hard way last summer. I’ve also been making a point lately to take apart fan motors that I’ve replaced to see what went wrong in them when I have the time for it, for a learning experience and out of shear curiosity. I had one blower motor that I could hear arcing in the attic while I was at the Tstat, just before it tripped the breaker. Took that one apart, it appeared that the bearings failed and caused the rotor to make contact with the stator. The windings were a blackened charred mess as well.
Hey bud thank you for taking the time to make these videos. Your approach to trouble shooting the best I’ve ever seen and very educational
I respect the integrity to which you do your wk. Your customers receive the best return for their $ spent. The BIG PICTURE battle cry has helped me in my own job to keep me striving to move further in diagnosis. We all need the reminder when things get summer crazy out here. God bless you and family, I appreciate all you have done and are doing!
You're showing your age with these daggy 80's soundtracks Chris.
😆😆🔥❄️
Maybe Try sealing contactor so sand can't get in. Do Quality work tighten wires to spec. reduce contact resistance and overheating. Replacing cover and panels to prevent Sun UV deterioration and sand infiltration. These thing may help. All the best to you. Thanks for the video.
Yet another great video. Been busy over in the uk aparently our ac units cant handle a bit heat
A wealth of information here. Thanks!
Thank you
Nice job explaining things and showing the inside of the compressor really helps.
I like your videos. Very professional.
Worked on identical unit last week. 2nd stage compressor shorted internally. Only difference was it blew out the L2 pin and the entire refrigerant and oil charge. Was a serious mess.
This is a great video! I am an HVAC Engineer and your videos are def helpful for the design too. Keep up the good work💪🏻
I love the music around the 30 min mark. Was half expecting the camera to turn and show John & Ponch riding up the road, turning on lights and sirens 🚨 and then nailing the throttle!!
Always love your vids always keep
Me sharp and on game whenever im working or air conditioning I’ve done learned a lot from your vids made me definitely a better at all this stuff keeps me motivated and just want to show appreciation for your vids because i do
Understand that it takes time for you do so I understand everything you say in your vids super educated and clearly knowledgeable about refrigeration and air conditioning and some other interesting things I’ve seen yah done there but yeah you show me a-lot in just a video it’s amazing to me always waiting for the next one can’t wait to Start my own videos but yeah much respect and love man
Hi here in the UK we have three phase and neutral plus where possible we always use solid-state contactors with DC voltage
Excelente contenido, mi rubro es la refrigeración y aire acondicionado domésticos en Argentina desde hace unos 9 años, y en mi opinión sobran los motivos para reemplazar contactores mucho más en éstas condiciones, sin dar demasiadas explicaciones a quien diga que no es necesario, es porque evita mayores reparaciones y costos asociados, podrías también hacer un video para orientarnos sobre cómo y dónde cortar compresores sería genial ver eso, excelente tu trabajo y realización del contenido!
"Pocket sand!"
- Dale Gribble
On changing contactors:
The same situation has presented itself THOUSANDS of times during my career in electronics.
Relays, contactors, and the switches. They fail, and cause issues LIKE THIS!
HVAC, gate automation, shutter door automation, you name it I've seen it all.
It is a cheap component that can be replaced and prevent issues happening later.
Could you double up contactors? I.e. give the electricity a redundant second path in case sand gets into one of that pair of contactors and blocks it from making a proper connection?
@@Pystro No two contactors are the same, their speed to make/break will be different across the same batch, therefore one set will burn contacts and the other set will be hardly used and vice-versa. We tried this approach long ago in the early 2000s with gate automation- the solution was full VFD / H-bridge
@@thesoniczone Well, in my proposed use case the intent is to avoid single phasing (or other consequences of 1 of the 3 contacts staying open), which I would guess would then only happen for half a second at a time or so which won't burn out a compressor. (No idea if that's true, though. I'm not an electrician.)
The inspiration was that the contactors are dirt cheap compared to the equipment they are controlling, so you can avoid using more of them (both in terms of frequent replacing and in terms of requiring 2 of them to fail simultaneously before that damage can propagate to other components).
Secondly, if there's a grain of sand on a contact face, the current could go through the other contactor (while both contacts are "closed"), and thus avoiding arcs of electricity persisting around that grain long enough that it gets welded into the contact face - unless the contact face with the sand grain is the slower one to open, but even then you'd only get a transient arc.
But I agree. In these conditions some silicon-based solution would be preferable.
@@Pystro I was an engineer for 14 years but I traded it for a career in software dev. I was working at one body shop (software development house) around 2016 and the A/C failed, yet it had electronics to detect single phasing, and it displayed the error code which we looked up before calling a service technician. We indeed did single phase and because of a wire that burnt off (YELLOW PHASE). So it is possible to detect these conditions electronically- I don't understand why they don't do this though on these commercial units.
Saw belt deflection being tested. Wanted to share: the other day, someone taught me a formula for belt tension. 1/64 per inch on belt for deflection. So an example: an ax-64 belt should have 1 inch of deflection. An ax-32 belt should have 1/2" deflection... And so on. Hope it helps someone...
This music reminds me of the Saved by the Bell , Full House and Family Matters days haha. Love it
Nice video, very informative and interesting. Especially for me as a german to see all the differences between the us and europe.
Probably 3rd stage contactor damaged because of it works less and contacts are open most part of time, sand settles between contacts. Meanwhile 1st & 2nd stage contacts are closed and not so damaged. IMHO.
Cool work and investigation 🔎!
Good tip on keeping your grinder to shallow cuts, one to keep debris out, but also two it can preserve the life of a cutting wheel. In my experience plunging the wheel wears it out so much faster, especially since little twists can wear out the faces of the disk making them just disintegrate
Always make it to the end! I've said forever that I'd love to be able to put a motor starter/contactor cabinet down in the building. It would take a ton of wiring from each unit but if you could put all the VFDs and contactors inside the building, it would certainly prevent a lot of failures.
They sell sealed contactors that have enough of a cover to keep sand out. And the unit could be designed to keep it's own control electronics cool even if it's mounted outside - it's a f'ing box that literally makes COLD AIR. My first thought is "mount the control and VFD in the conditioned air space", but then "what if the VFD blows up? All that crap gets sucked inside - that's bad" - ok fine. Idea #2, mount the control and VFD on a heatsink that sits on the cold air side of the unit, but the parts themselves are still on the outside side. These things are just designed to be cheap, and fail. They could also include current monitoring on every compressor and fan motor in this thing, and detect failures long before they actually happen, and for not very much BOM cost, but they don't do that either.
I will discuss this on my livestream this evening 7/25/22 @ 5:PM (pacific) on RUclips come over and check it out… or not ruclips.net/video/5HS0Ag5fTes/видео.html
Just so you know, some (usually older) breaker panels don't have isolation for the connection points where the wires will connect to the panel for the individual, breakers so it can be risky to work inside the panel (ie replacing the wires) as you can be very close to live busbars or connections. That's maybe why they needed to shut the whole building (panel) down.
Or the piece of crap Zinsco breakers and panels...still in use out there.
Hey buddy I like your style you always look out for the next guy coming up I've been watching your videos for a couple years now and I watched them all to the end you make it sound exciting you have to love what you're doing I tell the young kids today you have to love what you're doing I can tell you love your job I'm the same way keep up the good work Buddy
I always put into the vapor side and flip the tank upside down and it goes very good everytime
Great detail video! I’m an HVACR Technician Las Vegas.
I think your hypothesis is correct. I know what sand does to your relays and contactors. Sand is a very good isolator. So it is very easy to get one phase missing situation which burns your motor. That is why motor protection circuit breakers are recommended.
Great video! Liked your call on blowing system with nitrogen, checking oil and looking at the bigger picture and changing all compressor contactors. Hard to find techs who analyze and solve. Also enjoyed the compressor autopsy. Gave us a view of something we normally wouldn’t get to see and learn from. Thanks for taking the time and energy in sharing quality info! Btw, that heat strip opening in that carrier fcu is supposed to be blanked off if heat strip is not installed. A bit of supply air short cycles back to negative section. Carrier has been getting away with this forever! Ok done ranting! Keep em coming!
Love the 80s theme music in the back ground 😆 😎
I'd consider to use a big lathe (works for round compressors, not oval) or a milling machine to cut the compressor open. But you use what you have at hand.
This is why I put phase monitors on all my equipment...needed or not. Condom principle...better to have and not need than need and not have...one day it will safe thousands if not more...
The armature looks like it was contacting the steel laminations of the field windings; my guess is that the lower motor bearing failed and the drag caused by the bearing failure caused the motor to be incinerated
I’m surprised you don’t have a molecular transformator for 410a recovery in that heat! I just got one to recover about 30lbs of 410a for a compressor change. It was high 90s in the Michigan summer and that thing made a HUGE difference in recovery time. Just dropped it in a bucket of ice water and let that machine suck. Never got over 300psi in the tank.
I will discuss this on my livestream this evening on RUclips 8/1/22 @ 3:PM (pacific) come over and check it out ruclips.net/video/HSIOTgOXxV0/видео.html
Lock out and tag. I highly recommend this. Great video
The saxophone music. Perfect. 🤣
The contactors looked like OEM, that is usually overlooked, and or ignored by most techs who come to do a hurry-up maintenance. Voltage Spikes in a building are real, could it be when the other unit had its problem with the wiring that this occurred ? As for the (2) Two condensing units blowing towards it !
most definitely an issue. Heat of compression cannot freely escape. Solution here is a deflector shield
great video, really liked the time it took IE extra help lumping equipment.
EET here! Could have been a rub in the insulation of the magnet wire, happens from time to time when manufacturing motors and transformers. This kind of issue could be dormant for years, then one day the winding get shorted to another one and the motor gets oversaturated and overheats.
Really thinking about getting into air-conditioning now, i use to work in the feild only on the electrical and controls side
Saw this whole video coming back from Vegas. Great video
I like to do an acid test on the oil and add an HH filter drier and acid scavenger if it is positive.
Also could you go into more detail on how to use setup, remove a micron gauge. I flooded mine with refrigerant and am saving for a new one
I had the same exact thing happened to me on the same exact unit. Third stage compressor went out, and going back through it and found it was single phased
Awesome video thanks for the autopsy
Skilled technician with perfect tools
I see quite a few comments indicating potential failure points on this compressor, I do want to add a few other electrical things that may have led to this. That contactor looks like it took a lot of heat on all three phases. Now it was already mentioned that the third stage is going to cut in and out far more than the others when it is operating, but that also started to make me think. You could have had single phasing, but you could have just had a plain case of low voltage. The overload looks like it also took a lot of heat due to the bluing I see. Now that could mean excess current flowing. A few electrical conditions that will cause excess current over a longer period of time would be single phasing, under-voltage, and even mechanical overload which was also mentioned in another comment regarding the rotor rubbing the stator. I think all of these factors (Single phasing included or not) lead to the burn out. The third stage activates when there is a heavy load during high heat, this is when the power grid is at high load meaning the potential of lower line voltages. Even if the voltage was in specification, you have the stator and rotor in contact with each other, this means slightly more time at locked rotor current and you could...at least in theory have failure to start and the overload cutting in and out a bit. If there were cases of single phasing this would be greatly amplified.
Washington state is in the 90s right now too. I’m so glad I have a 14,000BTU unit even if it only keeps my 500sqft apartment 70F since it’s on the 6th floor.
Only 70F? How cold do you want it?
Here in Texas I'm lucky to hit 73F during peak times.
It’s easy to see someone else who is doing something wrong. It’s harder to do the same thing. The trick is learning how to control the grinding. Still it’s very informative to hear from your experience.
Un-brazing the discharge line of a scroll compressor is a bad idea.
That said, you're a quality tech and I like your videos.
Made me laugh out loud when you were shaking those wires because I immediately thought of a situation where I did this and no problems and a day later I had to come back because AC wasn't working.
I was like "what the heck?" go back up there check my wiring and it took about 15 minutes, but I found one broken wire about an inch below where I just stripped and put on a new wire nut.
45:12 nice offroad? wheel mod for your cooler.
if you are ok with running the compressor and cycling the overload protector on and off you can use the overloaded state to warm up the compressor so the gas will boil out of the oil and recover easier.
metal flakes in the oil means you are well on the way to destroying the compressor and blocking up the txv/cap line and even radiator coils if they are like car radiators with small channels.