LENNOX PACKAGE UNIT HIGH HEAD PRESSURE
Vložit
- čas přidán 31. 07. 2019
- This was a call on a Lennox package unit that had high head pressure. I found the the units condenser was a little dirty, the run caps for both condenser fan motors were bad and the unit was slightly overcharged.
To support my videos please visit either of the links below
For Patreon / hvacrvideos
For Streamlabs streamlabs.com/hvacrvideos
-TOOL LINKS
Fieldpiece Sman 480v- amzn.to/2SLOOYF
Samsung Tab A amzn.to/2IZxSKY
Ottor Box case amzn.to/2ZWYIZZ
Fieldpiece JobLink probes amzn.to/2XeiKNI
Veto Tech MC- amzn.to/2K4eqNH
Veto Tech Pac- amzn.to/2YGhXKB
Fieldpiece SC660- amzn.to/2SQHUS8
For Optimizing my videos I use Tube Buddy
www.tubebuddy.com/HVACRVIDEOS
Please consider subscribing to my channel and turning on the notification bell by clicking this link goo.gl/H4Nvob
Social Media
Facebook / hvacr-videos. .
Instagram / hvacrvideos
For any inquiries please contact me at hvacrvideos@gmail.com
A couple years ago I installed about 100 new Lennox RTUs on two buildings. We were having head pressure issues in October and November in Phoenix. Lennox engineering decided that the units were overcharged for our climate. I think we reduced charge by about 10% per unit to resolve the issues.
2:48 It's an led matrix, meaning the LEDs are wired with a shared anode going in one direction (either up to down or left to right), and a shared cathode in the other direction, this means that only one row can be controlled completely independently, so the displays light up one row at a time, usually using a crystal clock which isn't running at the 60/30FPS of the camera
Pushing in the wrong contactor can be dangerous and may I add expensive and likely non billable
Great advice as always Chris!👍
1:56 I didn't know that could happen and I've been working on these for a few months now. Your a life saver
I just found your videos
I enjoy them very much.
Only complaint.... "VFD Drive" is redundant. You are actually saying Variable Frequency Drive Drive....
Keep on keeping cool!
Love the technical diagnosis man!! Deep info! 🔥
Another great video. Been doing HVAC for 38 years and I think I'm pretty smart but I always seem to pick up a little nugget of knowledge from you. However, I only rinse away the crap from the condenser around the unit so I don't have to kneel in it later when I'm checking the performance. Yeah... call me selfish... it's all about me.
I enjoy your honesty! Keep up the good works!
Had a Trane unit with 25uf caps motors required 10uf. This caused the motors to over heat and trip internals. I think you should have checked the bearings on the motors. Amps can show ok but bearings can be worn heating up the motors and tripping internals as well. Good video. Always add Freon it fixes everything lol jk.
not to mention weak capacitors can cause improper rpm, but that's often reflected in current reading
Great video. I'm not a tech but enjoy learning new stuff.
Nice job I am learning everyday I’m not a super tech thanks for the help. I started just residential with my company. I now do commercial but refrigeration is still a learning curve for me.
I’m just starting to work on package units and I’m learning quite a bit from your videos. Thanks so much. Keep them coming
I will be going live on CZcams this evening 8/19/19 @5:pm
(pacific time) to discuss my most recent uploads and answer questions from
CZcams comments, the chat, and emails. Come check it out if you can czcams.com/video/cFVJGl-KVEc/video.html
You the MAN!!!! Thank you Chris I learned alot from you!
Loved the tip on taking the amp draw of the condenser motor off the relay.
Thank you for taking your time and putting this videos out man, I'm a 24 year old tech and I've learned a lot from you 👍🏼
Like your veto backpack setup. When I did residential service work I pretty much had the same set up as yours.
Chris what you should do is put your phone at 1080p 60fps because the lcd refresh rate is 60 and it will read it I tried it with my phone and I had no problem
good idea. i run my iphone at 1080 60fps too. much clearer video's too.
I agree
Good job troubleshooting and telling how to check the troubleshooting for good data. When something isn't working correctly it is easy to get blinders on and read all bad signals as if they are real but it is wise to double check the troubleshooting data. Troubleshooting the troubleshooting before moving forward is a wise move.
Great Video, I never have ran across VFD Drive, so I just learned something new about pushing in contactors randomly. I have ran across low indoor airflow with a TXV that actually caused high side pressure switch to trip, being it was on a Friday night I took the sensing bulb off the suction line till I did repair the following week, the unit did keep running without tripping high pressure switch. I hope you will still do those other videos with your wife, I know you said it was not as popular, but I liked them from another owners aspect of running a business and having a family.
Superior Comfort Heating & Air LLC had a Trane heat pump last week that the txv did that. I also like his wife videos.
Great video 👍 Just had a similar thing happen to me on a Lennox Energence 20 Ton RTU due to low airflow (dampers closed) -it was very weird- it had low suction pressure, fairly low superheat, the subcooling would start out normal and then climb to 45-50 degrees and the head pressure would climb quickly at that point until it tripped out on high head. After the first strike, the second and third strikes would only take 2-3 seconds to go from 300psi to cut out(675psi I think...). I suspect the low load on the evap due to low air flow (even with 89 deg return air😲) was allowing for normal superheat with very little refrigerant flow through the coil and started to stack the refrigerant up into the microchannel condenser.....causing the subcooling to climb until critical mass was acheived. It behaved the same for all four circuits. As soon as we located the closed supply dampers and opened them everything ironed out and ran fine. Very frustrating 😠. Thank you for all of your thorough videos-keep up the good work 👍.
I know it sucks but with package units, really good diagnostic is to recover and weigh in.. With that said I would have quadrupled checked my tools especially my vapor temp. I was wondering about the airflow this whole video... This guy puts out awesome videos I share with my guys all the time for training, absolutely love when we can have discussions about this stuff👍.
tough way to learn that lesson, i bet that dude never pushed in a contactor ever again.
Once I was soldering caps on some vacated kitchen plumbing pipes, in a bank. Tripped a smoke detector even without causing any smoke. The bank manager didn't know how to shut off the alarm n a fire truck showed up. Lessons learned by this kind of stuff are not easily forgotten.
@@jpp9876 i did the same thing in a hospital , welding in a condensing unit. i Met Everybody that day ! Fireman, Police, Building maint guys, and on.
@@jpp9876 lol
@@OcRefrig major whoopsy :))
@@throttlebottle5906 laws of physics are pretty reliable. Our lack of understanding them all can get us in trouble.
Great job Chris.
Always very helpful videos.
Please keep the good work.
Thank you for making these great videos.Love your step by step analysis. You help me become a better technician. Keep up the great work.
I'm laughing. Your talking about ice on the roof and it's 95 degrees outside. Your in the zone.
You should try working here in Buffalo, NY where you have to shovel your way to units on mall roofs.
Nice find on the run caps, common high head issue that happens when your not there
Sean Mack I was thinking the same thing?
hey bud , you should try to work here in quebec. winter like 8 month i hate it so much. would love to work where he work with no humidity
Great and instructional video as always Chris..keep them coming. Good catch on caps
It was mostly likely run caps, bad run caps can cause a hp issues, let alone burn the motors up, good you caught that before it damaged the motors to much.
Awesome video I had no ideal this line of work could be so dangerous!
I recently had that happen on a Lennox unit I was working on. One of the run caps was weak and was causing the other condenser fan motor to run backwards. Sometimes both would run backwards if it was windy enough.
TFW at 4:13 you realize the problem is someone put a REALY in, instead of a RELAY
That is awesome!!! Good eye. I could have watched this vid 100 times and would have missed it every time. That obviously was misspelled on a ton of units before they caught it and revised the diagram.
@@hvacguru-Kansas Made in China
Thanks for the video, more advanced troubleshooting and fine tuning.
Thanks for the contactor warning.
You are the best. Thx for teaching us
You have to be very careful pushing in the contactor no matter what the situation is, and always use something insulated to prevent shock, one time I pushed in a regular contactor to test it and it sparked bad because few strings of one of the legs was actually touching some metal by it, thankfully I had a insulated screw driver to tap it, otherwise I would of had some juice run through me.
The LED marquis display is a multiplexing display, so it has an actual refresh rate and of course different than the camera, as you had mentioned. You had said you didn’t know what caused it, so there you go. :)
Always re-mark the units I work, for easy ID. Malls are the worst when you get new contracts. Having to call the north east monitoring companies, also can get tedious. Good stuff for beginners and veteran hvac people ! Thanks, PEACE
I always chuckle a bit on the inside, when people make fun of wearing kneepads. It's almost like they are completely unaware of the fact. That they won't have any cartilage in their knees, by the age of 60, maybe a lot sooner...lol!!!
I love the backpack. Its so much easier to carry on those roof ladders that have those saftey cages around them
Well done
I like it how they misspelled relay on the legend
I like how simple Lennox makes their wiring/diagrams tho.. even tho I think prodigy boards are straight trash
Do you have a restriction tho?
Shap shap chris nice work bro happy new year
Bad ass tech learn something new in every video thanks 👍🏼
Great video
I try to carry my M18 leaf blower if I’m washing micro channels. It’s amazing how much water comes out
Great tip
I have been dealing with micro channel for the last 12 years never thought about using a leaf blower as an option, great idea Lucas👍
i use a co2 tank to blow out the coils. a leaf blower is lighter. thanks for that !
@@OcRefrig did I not mention cordless blower to help cleaning in the past? maybe it wasn't on your videos, I ricochet all over the place lol
if it's really stopped up, compressor or tank is still better, more velocity and pressure in a smaller area.
I carry my blower with me everywhere I go.
Good job.
Have a Aaon unit that trips the breaker but not a fuse. It doesn't go off on high pressure either. In weather over 80f or thereabouts I have to spray water on the condenser.I did remove some charge like you had to but it still trips the breaker. As long as a bit of water sprays onto the coil it will run trouble free all summer. The coil is very clean and in good shape. Just one of those crazy things. I tried moving the condenser fan blade up and down , same problem. New oem motor and and blade too. Amps do go up with the heat as would be expected.
Greg M use an infrared on the breaker see if it’s getting hot. The breaker could be the problem. Also at the disconnect. A loose connection will cause extra heat and trip it as well.
Great video!
I have had my Klein backpack for years now..its like 60-70lbs. But it saves on trips back and forth.
Yeah same here.. although I do want a Vito pack. They are nicer and better balanced.
Dude, you so rock. 👍
great advice, nice video
I lot of good tips in this video.
I wonder if the under-performing capacitors could have been causing the fans to turn more slowly, in turn causing the high head pressure? Would be interesting to re-check performance with the new caps installed. Might show slightly undercharged now?
I have personally seen motors kick on with bad caps, run correctly, and then after a few minutes/hours hit internal OL or even start running backwards. Most of the time when I have a bad motor the cap will discharge when I short the terminals. A cap with improper mFd for the motor will cause more heat and a shorter life.
The motors will overheat quite often when the capacitor is weak. This will cause the motor to trip the thermal protection which resets after a few minutes.
if you increase the shutter length youll get a good picture. (make the shutter stay open longer). if you have a cheap camera you probally cannot do this.
just bought the veto tech pac. Its SUCH a hard decision to pick from the awesome VETO lineup.
next up are the joblink probes; its been difficult to convince the wife why i need them though....lol
I did the bubble thing the other day on a Lennox just like that one. Lol
Thank you for putting the Link for the Veto Tech pac. it Looks nice. i'm going to check it out.
in your veto bag if u want to lighten it up a bit. you could remove the tubing cutters and that small crescent. i believe u have 2 - 8" crescents allready. i don't believe your going to be using tubing cutters on a service call.
that's for the next level bag thats needed when cutting into a system, welding evac etc. i'm thinking.
also i'd probably remove those demo screwdrivers at least 1. maybe those tin snips too. i'll bet u don't use that often.
What u could do is:
For 1 Week Take a Picture of Every tool + everything u use out of your service bag and that's what i would prob keep in my tool bag.
Nice!
Another great video learned something again from you I work more in building automation then refrigeration but do you both and you help me understand more more the little things they can make a system work real well. Can you make any more suggestions with micro channel coils to me i’ve done my own reading and research what is there anything else you need that you could pass along? Have a good day!
The problem is the TXV's are sticking or the screens (if equipped) have debris in them. If no screens at the entry of the TXV's then debris is stuck inside the TXV's preventing them from reacting correctly to the super heat sensed by the bulbs. Essentially the TXV's are locked down. If they are adjustable TXV's then loosen the spring pressure on the valves to open them up. It's not an overcharge situation. The caps needed changed but not the problem.
If they are not adjustable TXV's remove the bulbs from the evaporator outlet lines and watch your head pressures go down and suction pressures go up. Add A/C renew, run for a couple days then put the bulbs back on the lines. If no change in pressures after removing bulbs then the bulbs must likely lost thier charge and replace the power heads on them (if that type of TXV). If not replace the txvs
Nice videos keep it up
Sub cooling should be around 7-9 on those Lennox models in my climate at least . Also the newer style prodigy boards are in black font . They got rid of the bright red font and over sized white box . I just landed 100 Lennox energence series models , “via helicopter” . Then I got trained later to do startups on the new logic . Lennox is # 1 !
Till da end 😎
Your the reason CNN's ratings are tanking , everybody's watching your vids ... Lol ... As soon as you take the scissors and c-wrench out , you'll need em ... Much appreciated Chris ...
If it weren't for empty airports, CNN would have 0 viewers.
I’ve had like 9 different Lennox micro channels over charged straight out of the factory.
I like your videos.
I like the tool bag. My next bag has to have wheels. By the way, moisture can increase head pressure- might need to check the oil. If checking the oil sounds like too much of a problem, make sure the crankcase heater is working properly.
This stupid site isn't letting me edit my comment...
And I'm calling it right now, the cause of higher than normal head pressure was moisture or contamination, and it was more than likely from putting gauges on it every now and then. I still do not know the best way to hook up gauges without contaminating the system, as there will always be a little crossing when connecting.
@@DW-vl2wi Fieldpiece Wireless pressure probes or Testo ,other brands are available too. If you need to add refrigerant Schrader core removal tool or use a tee appion makes .
@@Gcanno Just checked those out. Put my man3 to shame. Damn.
If you turn down the exposure sometimes you can get the camera to pick up the multiplexing
Nice!!
Would like to see a video of the bubble machine😂
probably just fan motor rpm's slow from low caps, the dirty coil and overcharge stacking liquid and heat up in the coil.
I believe there's a point of weak caps that will slow the motor down and decreases the load by fan blades, that could fool anyone into thinking all is well when seeing lower than average amperage.
in theory they should not be overheating either if the current is less also. the controller could be trying to compensate by ramping up the vfd drive, who knows, but it sounds like something they'd do :))
Miss working on the units, but not the work getting to the units.
Last big place was at had a 14 achre roof
Solid
Here is my OCD problem.
If I was the architect of that building I would want purpose built drain line support.
Something made of stainless steel or UV protected poly.
I can tell you right now if the German's used AC they would never settle for blocks of crappy wood for supports.
Does the blower running direct off of contactor vs digital drive control effect system performance or charging? I assume that blower runs at full speed off contactor vs partial due to load?. Thanks
No doubt you would be a good instructor and thanks for the tip about not blowing anything up. Wanted to know your opinion on reusing reclaim refrigerant. How do you deal with that.
Good vid. i was thinking capacitors too. good catch. subcool awfully high with low temp on liquid = restriction in liquid line. older unit, driers full of shit / coming apart. recommend replace driers and metering device. metering device with crap in it. i'd do one stage and see what u find. oil turning to tar ? i would have liked to see discharge temp ? You know u can buy those probes seperateley now. maybe get 1 more fieldpiece probe. i'm going to get a few.
Question: That was a 10 ton Profile --- your only working on 5 tons worth of unit. each time u Profile.
some people might profile at 5 Tons. maybe worth a talk on your talk sessions. Profiling measure quick with multiple compressors.
2 - 5 ton compressors right ? interesting question For Jim B.
Thinking about it the air flow is 10 Tons so, i guess profiling at 10 tons is Proper ?
Condenser coil cleaner bubbles video, please 😄
👍👍
Cold liquid line ? Maybe the compressor head cooling is sticking open.... seems like that would make weird temps throughout condenser... just a thought...
sir thank you for your nice and interesting videos...Im asking if what is the best for low temperature refrigeration ..it's. resiprocating compressor or scroll compressor ????
👌🏻😎
👍
I wonder, how often do people wire their burgular alarm "ARMED" output via a inverted relay to the occupancy input of the AC? (so the occupancy input would be shorted and set to OCP when the alarm system is in a disarmed state)? If rare, I think it should be done more often, since using the burgular alarm's state is a smart way to know a building's occupancy state.
@phillip perkins Many ACs want to know if the building is occupied or not, to know if it should run in an lower "economy mode" or "full mode". This is done by having *something* to tell the building occupancy status via an input called "OCP" on the AC, which should be shorted to +24v to tell the system that the building is occuped.
Now to the smart idea. Many technicials install unneccessary occupancy sensors, when you actually, in most buildings, have a very good occupancy sensor - the burgular alarm system.
Most alarm panels do have a ouput, called "ARMED", that is pulled high once the system is put in a armed state. Usually this output sends out a +12v (most alarm systems are +12v) signal when the alarm system is armed, which makes it a effective vacancy signal, that instead tells when the building is empty of humans.
The smart idea is to wire this "ARMED" signal (since you would want to invert the vacancy signal to make it an occupancy signal) to an +12v relay, and then wire the relay's COM and NC outputs to the OCP and +24v signal on the AC.
The net effect is that the OCP signal will then be high when the alarm is disarmed (either by a employee scanning his access badge in a access reader on the morning, or entering the code in the panel to disarm the system) and the OCP signal will then be low once the system is armed (either for example the last employee entering the code in the panel to turn it on, the last employee pressing B and then scanning is badge or similiar action, or by timer, that the alarm system is turned on like 16:00 every day automatically if not armed before).
Another good source of an occupancy signal, if you don't have a building alarm system, is to put an microswitch inside the door jamb of the night lock and wire the microswitch's NC output to OCP,, or if the night lock is equipped with a microswotch position inside the lock body, so when the last employee leaves and locks the night lock, it will push the microswitch in and thus disable the OCP signal, tellig the system that the building is now empty.
Can i get the information on the fieldpeace devices that you are using to check this unit on the video
Thanks bro
Another Check this Taken from ACHR News www.achrnews.com/articles/102428-checking-for-noncondensables
Common causes of elevated high-side pressure on systems using an air-cooled condenser are dirty coils, insufficient airflow across the condenser, and recirculation of condenser air. These possibilities should be investigated first before looking at noncondensables as the cause.
If a technician does suspect the cause of a system problem is noncondensables trapped in the system, the following procedure can be used to determine this on a refrigeration system that has an air-cooled condenser.
• Determine the type of refrigerant in the system.
• Electrically disable the compressor and allow the condenser fan to operate.
• Attach a temperature probe to both the discharge line and liquid line.
• Place a third temperature probe to measure the temperature of the air entering the condenser.
• Connect a pressure gauge on the system to measure the pressure of the refrigerant in the condenser.
• When all three temperature probes - discharge line, liquid line, and air entering the condenser - are at the same temperature, record the pressure of the refrigerant in the condenser.
• Using a pressure-temperature chart, convert the measured pressure to its saturation temperature.
• The converted temperature should be within a few degrees of the measured discharge, liquid, and air entering temperatures.
• If the converted temperature is higher than the measured temperatures by more than a few degrees, there are noncondensables in the system that need to be removed.
Publication date: 1/08/2006
What doesn't make sense is why do VFD bypass contactors stay uncovered? Couldn't they use an ice cube relay or a different relay type?
Surprised Measure Quick doesn't not have an external source for outside air such as a weather site for your location.
Very informative videos!!!!!!!😀😃😄😁😁
My main question is that: do you charge your customers for HOURLY RATES OR do you charge your customers for a FLAT RATE INCLUDING A diagnostic fees?????????????????????????
I'm probably talking out of my back side , but would it be possible that there was uncondensables in the circuit ?
Nice video and you didn't blow anything up 😁😁😁
you must have one happy team. i would be if i was working under you. (Cyber Hi-five)
How do you like your tool bag? I’m looking at getting the Veto pro pack LC. Bigger than your bag but I’ve only ever had Jensen bags so I’m just curious about daily use. Thanks.
EDIT: 13:40 well that answers that question. Never mind. 👍🏼
My head pressure is always high in the morning.
As I understand it your camera and the unit scroll rates do not sync up. Cameras scroll video in different ways horizontal and vertical are two ways. Sometimes you can turn the camera sideways and it will correct the problem putting the unit scroll and the camera scroll perpendicular to each other and allowing it to be viewed. Either way no worries as long as you read them out. I will try and find this video of it that I watched a few weeks back and post a link.
Here is the link of a video that explains this effect.
czcams.com/video/dNVtMmLlnoE/video.html
Had same problem on a couple of these units. The head pressure will start to climb after 10 min or so and that same hi sc. Maybe something to do with the microchannel coils.
i love pushing contactors in.. easy way to know if u got enough gas.. no lennoxs where i live.. no problem
Will bad run caps cause the fan speed to lower?
Funny you should mention that. I don't remember which video it was where you were cleaning a couple condensers using a coil gun and coil cleaner. What coil gun and cleaner do you use? I have an older Nu-Calgon 4774-0 but have lost the quick coupler that goes on the hose nozzle. Looking to acquire another coil gun.
Donald Dayton I use a miracle grow fertilizer on my hose. Drilled out the air port for more cleaner and it works great. I use Master Coil cleaner. Best stuff I’ve ever used. Order it through Johnson Supply.
Update: I-found the video I-was looking for
Can I ask. What software are you using with the fieldpiece job link kit? Is that the fieldpiece job link software? I only ask as I downloaded the app here in the UK and it looks very different. Thank you for the uploaded videos quickly becoming one of my favourite learning channels 🙂👍
Measurequick Is the App
@@HVACRVIDEOS thank you really appreciated 🙂
would you ever work on a 100 ton chiller unit?
Why are all your videos about units that are screwed up? You should do a video of bits about systems that run like a champ and why they are.
Did the head pressure come down more after you replaced the run caps?
No the head pressure stayed the same