Close the high side first, close the low side maybe 1/3 or 1/2 the way, turn on the thermostat, then connect power to the disconnect. I try to always have the indoor fan running, get some heat on that coil helps it pump down fast. Once you hit zero, pull the disconnect, and close the suction valve as fast as you can. Done!
@@jamesdavid2043 thats what i thought as well, because by closing first your putting a barrier between the condensor and the copper line.and power well its power atlongest you cut if off so the compressor doesnt bust a load on ya
Absolutely great and helpful video I been in the air condition business for 22 years and I appreciate the fact that your professional and you know what you're talking about it's a great help to other people keep the videos common I learn something everyday and thank you again for your videos😁🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸
The system will pump down faster if you're running the indoor fan anyways, so always a good idea to set the thermostat to cooling, and the temp setting to minimum. If the indoor coil is cold already, and wet, and you use the screwdriver method, you run the risk of freezing up the evaporator coil, and with no heat to boil off the refrigerant, it's going to take awhile to pump the system down (been there, done that).
Nice video brother. Im am transitioning from commercial installer to a full service commercial/residential contractor. This info helped me out some. thanx
Easy, step 1. Make sure the unit is off. Step 2, hook up your gauges. Purge your hoses (good practice to do all the time anyway). Step 3. Make sure your high side and low side pressures are equal. If not equal, wait. If you aint got time to wait, equalize em yourself! Just make sure your yellow hose is connected to something and purged, and just open up both your manifold valves all the way!. Once pressures are equal, high and low, then close up your gauge valves. Then go ahead and pump down!
20 + years ago we always called that a "manual pump down" for line set less than 20 feet. You had all the right procedures my friend regardless of what others say.
I usually close the liquid line first then close the suction half way and run it with the contactor pushed in and when it hits zero I close the suction with it still running b/c won’t it migrate back out if you let the system turn off before you shut the suction?
After you powered off. Your low side pressure went up a little bit to around 20 or so. Shouldn’t you close the low side valve first and then power off to prevent that?
Well put. You called BS and you are right. You can do it either way and it will work just fine. You pumping it down from a dead stop or me doing it from its normal running state is a matter of preference. However, if you are doing this on a large unit and you do it from a dead stop, the oil will not be traveling at enough velocity to fully pump back to the compressor. This may be an issue occasionally. Just saying.
so i learned this by using the contactor and pressing the middle switch down. when it would get close to 0 we were told to start closing the vavle and try to get it to stop between 5 and 0
Was thinking the same thing, but then realised if pressure is less than 60 PSI, then all that is left in evaporator and line set is gas. By volume this is a very small amount of freon.
He had it down to 0 psi, why not shut it (low side) down there? It is not going to hurt the compressor any more or any less, the few seconds it runs while shutting off the low side. Common practice in the field.
Yep, as long as the high and low side pressures are equal, then should be no problem to start the compressor! If not, then you're going to need to check your contactor for burnt/pitted contacts, check your voltage, and your run cap mfd's etc.
There won't be any heavy startup load on the compressor if the system has been off long enough. There is a heavy load on the compressor though if you crank down that high side valve while it's running. You can't instantaneously close that valve, so while you have it 1/2 closed, you're putting in a restriction on the system, causing a big spike in head pressure. Besides, most modern units these days have scroll compressors which have internal unloading.
Bong Sill, the refrigerant is stored in more than just the compressor. Its in the condenser coils and discharge lines also. you pump down a system so u can isolate the line set and evaporator. ie- replace your suction line or replace a TX valve or an A-coil
turn on the thermostat?? yeah maybe that's "by the book" but in the real world we just push in the contactor relay contacts with a screwdriver and BAM! btw good tip about not closing the high-side valve right away and letting the system normalize so you don't put a heavy startup load on the compressor
Um yah you have to have manual control from the unit, if you pull a scroll compressor into or close to a vacuum, you can really damage it fast. I prefer to turn off the disconnect, then go back in and turn on the thermostat, pump the system down, with one hand on the disconnect so I can shut off power immediately. I use a screwdriver method sometimes, such as on a split system when the condenser is 3 floors up on the roof. Eliminates 2 trips up and down the ladder...
Yeah but you still have pressure on the gauge. So that gas is recoiliig back into the evap lines, maybe to a lesser degree but will escape if cutting the evap lines. Yes/ no ?
The best and most simpliest way is to close the high side and then close the suction side but once the suction is closed give it three turns back to open then press the contactor and wait for the pressures to drop close to 0 psig then close the suction now release the contactor and booo ! Baby ! lol
You have that backwards, when you front seat the valves, they read the line set pressure, downstream from the valves, not on the compressor. Your high side gauge should be reading about the same as the low side when pumping down. Some heat pumps have a 3rd access port, that always connects to the suction of the compressor, on the compressor side of the reversing valve, to make pumping the system down easier, or, to measure the actual suction pressure when running in heating mode. Cheers
dont neede to be open, because closed position makes possible to read on the gauges, you only open when you are doing the following: charging, recovering or vacuum; if you open the mainfold gaiges valves vapor and liquid will mix and could damage the compressor.
Vacuum uses the surrounding atmosphere to create work force by pulling on, rather than pushing. The pressure differential is what pushes the out the gas, not the compressor.
Good video. How do I disconnect the lines. Do they screw into the machine or do I have to cut them? The appear to go into the wall. Our unit needs to be temporarily moved, then put back in the same spot. Also, how do I know which is the high vs. low side? Do I have to add anything back to the unit like refrigerant?
Aren't you supposed to close the suction side first before you disconnect the power?? The gauge clearly showed it repressurized to about 20psi after you turned the power off. Can't just vent that into the air!
Damn, that's also true. Now I'm all confused... so which way is the better way?? We usually do it the former way i.e. close the high-side valve first and then pump-down...
Finally got it up and running. The only delays we had was because we realized we needed some extra parts (I’ll list that below) ruclips.net/user/postUgkxihMYiJNXcHdbH-7ihymsLz61l7jVyb5O . So we have a loft where our current hvac just couldn’t seem to keep cool during the summer. We have been using a window unit since we bought this house over 6 years ago (all the houses in this neighborhood were built in the 80’s and majority of the houses built like ours use a window unit). I hate window units because they are just so noisy and the one we had really only cools one side of the loft. I had contemplated upgrading our current HVAC, but with all the rising prices these days, it would take years before saving up enough to do that. With the advice of my father-in-law (used to run an HVAC business), he recommended we get an inverter instead. We thought we bought everything we needed, but there were just a few other parts we didn’t anticipate needing (which is what caused most of our delay). My friend and father-in-law did all the work to get it installed and running and now we have nice cool air circulating nicely throughout the entire loft. It is very quiet and even the outside unit is much quieter than our main HVAC unit. Saved ourselves thousands getting this.
Only question I have, maybe it's been answered already, what do you do with the remaining charge? I see your gauges reading somewhere around 25 PSI on the suction. Surely you aren't suggesting to vent that?
Hi i have a multi system ac unit which runs two indoor units off the one outdoor unit. I only need to take one of the indoor units off. Do i need to pump down both sets of units? Or do each of them have a separate compressor etc in the one outdoor unit?
Hi cory thnx for this informative video but I have questions. 1. Does the compressor have enough capacity to hold the refrigerant once being pump down without any damage to the compressor? 2. Does pumping down applicable to all types of compressor? 3. Why do we have to pump down a system in the first place? I have basics in refrigeration but I need more information specially its maintenance procedure. Thank you
Now is there any difference if you have say a piston compressor or another type of conpressor? The reason I ask is because a technician that know has told me that it differs per compressor type.
to prevent back feed of refrigerant you should close of valve before shutting off power. also should mention not to pump down into a vacuum to prevent air getting in system in case there is a leak. You don't want to suck air in.
no.. if u did pump down to replace the Schrader, u would have to pull another vacuum.. there is Schrader valve removal tool they make to replace the Schrader, without having to even pump down the system
I know about the tool I just wanted to know if I can do it without the tool by just shutting down the service valve not pumping down the system. it looks like I have to buy the tool
The access port in the valve is on the side that gets closed off. To read refrigerant pressure while pumping a system down it would need an access port on the compressor discharge line, or any other location on the other side of the valve.
I am a maintenance person at an apartment community and diagnose/repair only 2 ton condensers. I do not know it all obviously but am learning more. I just bought a house and someone installed a 3 ton condenser with a 2.5 evap. The unit can not keep up so I am going to install the new 3 ton evap myself. My question is i will pump down the unit, install new air handler, but as far as pulling a vacuum on the line, what is the best way of doing that when the freon is stored in the unit? I have actually put units in at the complex but the lead maintenance guy doesn't do things the correct way and that's why I'm even asking this (stupid) question. So, I just need to know how the proper procedures for pulling a vacuum after installing the new evaporator with the charge in the condenser. Thank you for your help.
well if you have already pressure tested with nitrogen and found no leaks then all you do is connect one of your hoses to the vacumm pump and obviously you connect your high side and low side and then you open up your high side and low side... on your gauges.. im talking about the stoppers, turntables and start pulling the vacumn if you reach 500 macaronis then you close your knobs on your gauges take your hose of the vac pump make sure your knobs are closed then you take your service tool and open up the valves then turn on the system inspect your charge add or subtract then go home
It's true, installation manual says it can damage the scroll compressors. Deep vacuum can cause scroll compressors to create internal static that can short out windings.
the Goodman condenser units that have a scroll compressor, indicate not to pump down the unit, the way you are describing it will damage the compressor.
If worried about damaging the compressor, then stop at 40 PSI. This will be like having a system low on freon. All the liquid freon will be in the condenser at this point.
from my understanding, when front seating and you have your gauges on, they read the pressure on the side the compressor (high side) which should increase when you storing liquid during the pump down. Why is the pressure reading on your high side gauge decreasing as if you reading the pressure in the liquid line.
Before hooking up the manifold, are both valves (liquid and suction line valve of the manifold, not the compressor) be "Close or Open". I haven't found any clip related to pump down even mention about the position of valves of the manifold. I tried this same procedure on a 3 phase Goodman, 5 ton, r410, slipped unit. it seems that both lines are at around 150psi and needles weren't move at all when Power Reset button on the condenser was pushed to ON, for around 2 minutes. Before Reset Switch was pushed, Liquid line's nut was completely" closed or front seated", suction nut was about a few turns left to be completely "closed or front seated". No power to Air Handler/evap. coil? Did I do something wrong or was missing something? Thanks. Please verify
if it was overcharged by quite a bit, then the most likely scenario would be the compressor overheating and cutting out on thermal overload. I'm pretty sure that it would not lock up.
This is for all you worry about pumping down scroll, if Goodman is telling you to never pump-down a scroll then ask them why there are systems with pump-down circuits and scroll compressors. Sounds like you guys are not that experienced. Cory Paeper did pump it down the right way, you never pump down to vacuum specially scrolls cause they go to deep vacuum quick and can damage internal parts (this is for any compressor), as long as you stop around 10-15 psi you can recover whatever vapor left in system.
I'm fascinated by a/c videos, some guys are too cautious, some guys ought to be in jail! It was great to see this, engineering background but not formally trained in hvac, I had a theory this could be done and it was great to see it! reading comments I now must research scrool / scroll compressor. btw I don't think it was a big deal the small pressure that came back before closing low side...
Brandon Quinnett1 second agoto prevent back feed of refrigerant you should close of valve before shutting off power. also should mention not to pump down into a vacuum to prevent air getting in system in case there is a leak. You don't want to suck air in.
You've got to remember too if it's a scroll or hermetically suction pump.Its not suggested that you pull down below zero in Scroll because of scroll configuration is weak under vancum poor design compressor for minimal vancum. now hermetically suction pump is suggested you pull them down into a 5 Psi minus what I usually do would have done is I would have started closing my suction line halfway and then started closing my liquid line while the unit was running the liquid line takes approximately 54 more cranks then of the suction line.
Can anyone tell me how to do this on a modulating heatpump? Inverter compressor is going out on error and shutting down before it pumps down all the way
no u can not.. when u pump down.. refrigerant is stored in the outdoor unit.. if u then start cutting away piping to compressor or reversing valve your in for a big surprise
it is a ratcheting service wrench designed for opening and closing service ports access valves. sorry i didnt let you see it. I'll remember that next time.
Shouldn't he have closed the suction side (the low side) while the unit is still running? This is how I do it. You can see his low side gauges jump back up as he pulls the disconnect and the charge bleeds back into the system
Close the high side first, close the low side maybe 1/3 or 1/2 the way, turn on the thermostat, then connect power to the disconnect. I try to always have the indoor fan running, get some heat on that coil helps it pump down fast. Once you hit zero, pull the disconnect, and close the suction valve as fast as you can. Done!
I close lowside first and then disconnect.
@@jamesdavid2043 yes to have little to no pressure in the lines
@@jamesdavid2043 thats what i thought as well, because by closing first your putting a barrier between the condensor and the copper line.and power well its power atlongest you cut if off so the compressor doesnt bust a load on ya
@@DJV94022 correct especially when you go hard and don’t use thermostat. Straight from the contactor 👍
Or just push in the contactor and simultaneously shut valve yall be doing the most.
Absolutely great and helpful video I been in the air condition business for 22 years and I appreciate the fact that your professional and you know what you're talking about it's a great help to other people keep the videos common I learn something everyday and thank you again for your videos😁🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸🇺🇸
Thank you Cory, too many “experts” in here but you are #1 in my book. Thanks again
The system will pump down faster if you're running the indoor fan anyways, so always a good idea to set the thermostat to cooling, and the temp setting to minimum. If the indoor coil is cold already, and wet, and you use the screwdriver method, you run the risk of freezing up the evaporator coil, and with no heat to boil off the refrigerant, it's going to take awhile to pump the system down (been there, done that).
Nice video brother. Im am transitioning from commercial installer to a full service commercial/residential contractor. This info helped me out some. thanx
boss you are the man...you instruction and explanation are very clear...you should make more video...thanks.. God bless
So when in the field we should all take the time and walk in customs home to turn thermostat on!! No heel no!! Glad your a teacher 👨🏫
I start HVAC school in fall seems like a great job field
Posted 6 years ago how did things turn out for you if you see this
How is it going
And no one has seen or heard from this man again lol
@@jacemenard9168Once he learned that he couldn't use cologne as a refrigerant, he "bounced."
Answer back bro it’s been 10 yrs give us your update 😂
You're the man to thank for sharing this information ℹ️ 🤛🏾
2:14 WTF??? LOL!!!
🤣🤣
Easy, step 1. Make sure the unit is off. Step 2, hook up your gauges. Purge your hoses (good practice to do all the time anyway). Step 3. Make sure your high side and low side pressures are equal. If not equal, wait. If you aint got time to wait, equalize em yourself! Just make sure your yellow hose is connected to something and purged, and just open up both your manifold valves all the way!. Once pressures are equal, high and low, then close up your gauge valves. Then go ahead and pump down!
awesome video. straight to the point and very informative. thanks
20 + years ago we always called that a "manual pump down" for line set less than 20 feet. You had all the right procedures my friend regardless of what others say.
you forgot to close low side before powering off
I thank you very much to share the knowledge to people . God bless your family .
Shut down hi side.push in contactor as nearing 0 on suction start quickly closing low side ,release contactor...finish
I usually close the liquid line first then close the suction half way and run it with the contactor pushed in and when it hits zero I close the suction with it still running b/c won’t it migrate back out if you let the system turn off before you shut the suction?
After you powered off. Your low side pressure went up a little bit to around 20 or so. Shouldn’t you close the low side valve first and then power off to prevent that?
Well put. You called BS and you are right. You can do it either way and it will work just fine. You pumping it down from a dead stop or me doing it from its normal running state is a matter of preference. However, if you are doing this on a large unit and you do it from a dead stop, the oil will not be traveling at enough velocity to fully pump back to the compressor. This may be an issue occasionally. Just saying.
so i learned this by using the contactor and pressing the middle switch down. when it would get close to 0 we were told to start closing the vavle and try to get it to stop between 5 and 0
Mario Munoz yeah that's the way I do it... Only I stop when it gets a little below 0 because when you shut power the pressure jumps back up slightly.
It's better to pump down with contactor incase there's a pressure switch which will shut the unit off before completion
Should really shut of the suction line before cutting power, just saying.
Was thinking the same thing, but then realised if pressure is less than 60 PSI, then all that is left in evaporator and line set is gas. By volume this is a very small amount of freon.
He had it down to 0 psi, why not shut it (low side) down there? It is not going to hurt the compressor any more or any less, the few seconds it runs while shutting off the low side.
Common practice in the field.
Agreed
yea it didn't pump down all the way to zero even
pressure wont blow back thru comp, so why bother you only pull a vacuum on the low side and contaminate the system if the suction seat leaks.
Yes. Absolutely. keep them closed for a pump down and open for recovery.
Yep, as long as the high and low side pressures are equal, then should be no problem to start the compressor! If not, then you're going to need to check your contactor for burnt/pitted contacts, check your voltage, and your run cap mfd's etc.
May god bless this man
This is a safe way to pump down. Thanks!
There won't be any heavy startup load on the compressor if the system has been off long enough. There is a heavy load on the compressor though if you crank down that high side valve while it's running. You can't instantaneously close that valve, so while you have it 1/2 closed, you're putting in a restriction on the system, causing a big spike in head pressure. Besides, most modern units these days have scroll compressors which have internal unloading.
Very nice explanation dudde ur Awsome
After pumping down can I already go ahead and cut the copper in order to move the unit ??
Yes
This video tutorial is gold
Bong Sill, the refrigerant is stored in more than just the compressor. Its in the condenser coils and discharge lines also. you pump down a system so u can isolate the line set and evaporator. ie- replace your suction line or replace a TX valve or an A-coil
The suction gauge raised up, you should close the suction valve first, before disconnecting the power on this unit
Hallelujah!
turn on the thermostat?? yeah maybe that's "by the book" but in the real world we just push in the contactor relay contacts with a screwdriver and BAM!
btw good tip about not closing the high-side valve right away and letting the system normalize so you don't put a heavy startup load on the compressor
Um yah you have to have manual control from the unit, if you pull a scroll compressor into or close to a vacuum, you can really damage it fast. I prefer to turn off the disconnect, then go back in and turn on the thermostat, pump the system down, with one hand on the disconnect so I can shut off power immediately. I use a screwdriver method sometimes, such as on a split system when the condenser is 3 floors up on the roof. Eliminates 2 trips up and down the ladder...
AWESOME TEACHER.
Yeah but you still have pressure on the gauge. So that gas is recoiliig back into the evap lines, maybe to a lesser degree but will escape if cutting the evap lines. Yes/ no ?
The best and most simpliest way is to close the high side and then close the suction side but once the suction is closed give it three turns back to open then press the contactor and wait for the pressures to drop close to 0 psig then close the suction now release the contactor and booo ! Baby ! lol
You have that backwards, when you front seat the valves, they read the line set pressure, downstream from the valves, not on the compressor. Your high side gauge should be reading about the same as the low side when pumping down. Some heat pumps have a 3rd access port, that always connects to the suction of the compressor, on the compressor side of the reversing valve, to make pumping the system down easier, or, to measure the actual suction pressure when running in heating mode. Cheers
very good explanation.
Your good. Keep it up. If turning the service port takes you long enough to cause a problem with the system, you have other issues. lol.
Nice very good job!!!!!!!
Aha, good tip on the fast equalize.
Yes of course it's a good practice to purge!
Subscribed to your channel! ;)
Yuo have to shut off low side too. absolutely.
you said it is stored all in the compressor... that is not correct
I refer to condenser unit as compressor sometimes
dont neede to be open, because closed position makes possible to read on the gauges, you only open when you are doing the following: charging, recovering or vacuum; if you open the mainfold gaiges valves vapor and liquid will mix and could damage the compressor.
You said compressors do not push... What do you think the discharge hot gas off the compressor is doing?
Vacuum uses the surrounding atmosphere to create work force by pulling on, rather than pushing. The pressure differential is what pushes the out the gas, not the compressor.
why do u power down before closing the low/suction
Good video. How do I disconnect the lines. Do they screw into the machine or do I have to cut them? The appear to go into the wall. Our unit needs to be temporarily moved, then put back in the same spot. Also, how do I know which is the high vs. low side? Do I have to add anything back to the unit like refrigerant?
when you hook the guages on do you open the valves on the manifold before you start the pump down or do you leave tthem closed?
Aren't you supposed to close the suction side first before you disconnect the power?? The gauge clearly showed it repressurized to about 20psi after you turned the power off. Can't just vent that into the air!
why didn't you close your suction line valve before you cut the power?
you have any good video to put the condenser back in service once you are ready to? Cory Paeper
Damn, that's also true. Now I'm all confused... so which way is the better way??
We usually do it the former way i.e. close the high-side valve first and then pump-down...
Finally got it up and running. The only delays we had was because we realized we needed some extra parts (I’ll list that below) ruclips.net/user/postUgkxihMYiJNXcHdbH-7ihymsLz61l7jVyb5O . So we have a loft where our current hvac just couldn’t seem to keep cool during the summer. We have been using a window unit since we bought this house over 6 years ago (all the houses in this neighborhood were built in the 80’s and majority of the houses built like ours use a window unit). I hate window units because they are just so noisy and the one we had really only cools one side of the loft. I had contemplated upgrading our current HVAC, but with all the rising prices these days, it would take years before saving up enough to do that. With the advice of my father-in-law (used to run an HVAC business), he recommended we get an inverter instead. We thought we bought everything we needed, but there were just a few other parts we didn’t anticipate needing (which is what caused most of our delay). My friend and father-in-law did all the work to get it installed and running and now we have nice cool air circulating nicely throughout the entire loft. It is very quiet and even the outside unit is much quieter than our main HVAC unit. Saved ourselves thousands getting this.
How do you pump down if the unit isn’t working ?
Close off the suction line valve before turning off the power so you don't get refrigeration back into the line set.
Should the gauges be open for this procedure?
Only question I have, maybe it's been answered already, what do you do with the remaining charge? I see your gauges reading somewhere around 25 PSI on the suction. Surely you aren't suggesting to vent that?
He did it wrong hahaha
I don't know about this .... 410a label right there and why would you leave the low side with pressures reading about 10psi?
But cant the gauges read pressure without the manifold being open.
nice one this is my work
Hi i have a multi system ac unit which runs two indoor units off the one outdoor unit. I only need to take one of the indoor units off. Do i need to pump down both sets of units? Or do each of them have a separate compressor etc in the one outdoor unit?
Hi cory thnx for this informative video but I have questions. 1. Does the compressor have enough capacity to hold the refrigerant once being pump down without any damage to the compressor? 2. Does pumping down applicable to all types of compressor? 3. Why do we have to pump down a system in the first place? I have basics in refrigeration but I need more information specially its maintenance procedure. Thank you
Now is there any difference if you have say a piston compressor or another type of conpressor? The reason I ask is because a technician that know has told me that it differs per compressor type.
lol so you shut the unit down before closing the low side and now you've lost some Freon to the evaporation side.
Pull a vacuum anyway😒
to prevent back feed of refrigerant you should close of valve before shutting off power. also should mention not to pump down into a vacuum to prevent air getting in system in case there is a leak. You don't want to suck air in.
Is their times when you cannot pump a system down..
Does this process work on a scroll type compressor?
Yes just don’t pump it down past 5 psi
awesome, and im assuming you can do this with R-22 as well?
Hello Mr Paeper, if that unit has a Copeland scroll compressor, is it recommended to pump it down to 0 (zero)?
If you’re hitting zero and not holding that contactor in then that system does not have pressure switches to protect that compressor
hey Cory was that a reciprocating compressor or a scroll in that unit?
Front seated or back seated, the service valves
so if the unit failed....... this does not help?
Were you using and Allen wrench? Why do pump it down.....
So this shut off valve also shuts the gauge? in other words can I use this shut off valve to replace my schrader valve? thanks
no.. if u did pump down to replace the Schrader, u would have to pull another vacuum.. there is Schrader valve removal tool they make to replace the Schrader, without having to even pump down the system
I know about the tool I just wanted to know if I can do it without the tool by just shutting down the service valve not pumping down the system. it looks like I have to buy the tool
The access port in the valve is on the side that gets closed off. To read refrigerant pressure while pumping a system down it would need an access port on the compressor discharge line, or any other location on the other side of the valve.
I am a maintenance person at an apartment community and diagnose/repair only 2 ton condensers. I do not know it all obviously but am learning more. I just bought a house and someone installed a 3 ton condenser with a 2.5 evap. The unit can not keep up so I am going to install the new 3 ton evap myself. My question is i will pump down the unit, install new air handler, but as far as pulling a vacuum on the line, what is the best way of doing that when the freon is stored in the unit? I have actually put units in at the complex but the lead maintenance guy doesn't do things the correct way and that's why I'm even asking this (stupid) question. So, I just need to know how the proper procedures for pulling a vacuum after installing the new evaporator with the charge in the condenser. Thank you for your help.
well if you have already pressure tested with nitrogen and found no leaks then all you do is connect one of your hoses to the vacumm pump and obviously you connect your high side and low side and then you open up your high side and low side... on your gauges.. im talking about the stoppers, turntables and start pulling the vacumn if you reach 500 macaronis then you close your knobs on your gauges take your hose of the vac pump make sure your knobs are closed then you take your service tool and open up the valves then turn on the system inspect your charge add or subtract then go home
per Goodman technical: you never pump down a scroll compressor!
Why can’t you shut the gage off when the machine is still running?
What if you have a low pressure cut off?
You have to bypass with jumpers
I called Goodman in Houston the tech told me that pump down a system especially a scrool compressor is not recommended.
It's true, installation manual says it can damage the scroll compressors. Deep vacuum can cause scroll compressors to create internal static that can short out windings.
the Goodman condenser units that have a scroll compressor, indicate not to pump down the unit, the way you are describing it will damage the compressor.
I pump them down all the time.
If worried about damaging the compressor, then stop at 40 PSI. This will be like having a system low on freon. All the liquid freon will be in the condenser at this point.
from my understanding, when front seating and you have your gauges on, they read the pressure on the side the compressor (high side) which should increase when you storing liquid during the pump down. Why is the pressure reading on your high side gauge decreasing as if you reading the pressure in the liquid line.
Before hooking up the manifold, are both valves (liquid and suction line valve of the manifold, not the compressor) be "Close or Open". I haven't found any clip related to pump down even mention about the position of valves of the manifold. I tried this same procedure on a 3 phase Goodman, 5 ton, r410, slipped unit. it seems that both lines are at around 150psi and needles weren't move at all when Power Reset button on the condenser was pushed to ON, for around 2 minutes. Before Reset Switch was pushed, Liquid line's nut was completely" closed or front seated", suction nut was about a few turns left to be completely "closed or front seated". No power to Air Handler/evap. coil? Did I do something wrong or was missing something? Thanks. Please verify
They should be closed.
Can you do this on a heat pump?
+celina gonzalez yep
This shit right here will save you about $200
question. if you tried doing this and the system was over charged to begin with, would the compressor start to lock up?
if it was overcharged by quite a bit, then the most likely scenario would be the compressor overheating and cutting out on thermal overload. I'm pretty sure that it would not lock up.
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Closes off lines = frontseat ????? Thanks in advance.
Yes
This is for all you worry about pumping down scroll, if Goodman is telling you to never pump-down a scroll then ask them why there are systems with pump-down circuits and scroll compressors. Sounds like you guys are not that experienced. Cory Paeper did pump it down the right way, you never pump down to vacuum specially scrolls cause they go to deep vacuum quick and can damage internal parts (this is for any compressor), as long as you stop around 10-15 psi you can recover whatever vapor left in system.
I'm fascinated by a/c videos, some guys are too cautious, some guys ought to be in jail! It was great to see this, engineering background but not formally trained in hvac, I had a theory this could be done and it was great to see it! reading comments I now must research scrool / scroll compressor. btw I don't think it was a big deal the small pressure that came back before closing low side...
btw, I would have liked to see a close up of closing the valves but assume it is not a big deal.
You mean you're just going to close the suction valve without "going ahead" and closing the suction valve?
Thanks for the video Corey
Did you have to recover remaining refrigerant in vapor form?
Brandon Quinnett1 second agoto prevent back feed of refrigerant you should close of valve before shutting off power. also should mention not to pump down into a vacuum to prevent air getting in system in case there is a leak. You don't want to suck air in.
You've got to remember too if it's a scroll or hermetically suction pump.Its not suggested that you pull down below zero in Scroll because of scroll configuration is weak under vancum poor design compressor for minimal vancum. now hermetically suction pump is suggested you pull them down into a 5 Psi minus what I usually do would have done is I would have started closing my suction line halfway and then started closing my liquid line while the unit was running the liquid line takes approximately 54 more cranks then of the suction line.
Can anyone tell me how to do this on a modulating heatpump? Inverter compressor is going out on error and shutting down before it pumps down all the way
Press emergency cooling button. Do it promptly before the machine realises
Can you pump down in heat mode to remove a bad reversing valve or compressor
Yes you can. Put it in heating and your indoor coil become the condenser.
no u can not.. when u pump down.. refrigerant is stored in the outdoor unit.. if u then start cutting away piping to compressor or reversing valve your in for a big surprise
Why would you do this?
it is a ratcheting service wrench designed for opening and closing service ports access valves. sorry i didnt let you see it. I'll remember that next time.
better hope its not a long run with extra charge.
What do you want to see next?
Shouldn't he have closed the suction side (the low side) while the unit is still running? This is how I do it. You can see his low side gauges jump back up as he pulls the disconnect and the charge bleeds back into the system
Why should pumpdown be used in cold room systems?
Yes they have a special pump down timer & solenoid to have a safe liquid free start on the next cycle