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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) ua-cam.com/users/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.
Why jump it out? When it goes off on low pressure, you can just push your contactor in. To me that's more to my benefit cause i don't have to pull the disconnect to stop it, just let go of the contactor plunger
It is just something to watch out for if running the system in ac mode. I highly encourage techs to have the indoor fan running during the pump down. This way, the pressure does not rise after the pump down process is complete due to vaporization, thanks!
I've been doing this for 30 years and I thought to myself I don't need to watch this what am I gonna learn and then I thought no I might learn something and I did Micro channel I had no idea that you couldn't pump it down on microchannel
Great stuff, Craig. With respect to pump down videos in general…I think it’s important to reiterate that outdoor condensing units do not have endless refrigerant storage capacity. Despite countless videos showing someone closing the LL, holding in the contactor, closing the SL, etc…and viola! Firstly, your professional recommendation (safer I'll add) is much better. Secondly, well, some times/often it doesn’t work so easily. Depending on evaporator size, lineset specs, etc. even brand new compressors will trip their pressure relief during pump down-puzzling many (here assuming limit switches were bypassed). In these cases, you trap what you can get and evac the rest. My point is IF you think you’re going to always conveniently ‘pump down’ every system into its ODCU, you’re mistaken. I’ve had brand new units pump down to around 225 psig on the LL and that’s it.
Great instruction Craig. In previous pump down videos you have advised that due to the insulating properties of the refrigerant in scroll compressors not to pump down to a vacuum, but only go down to 5 LBS psig. In this video you advise NOT to pump down systems with Scroll Compressors. Please explain the change. Also, please do a video on just how you now would pump down/evacuate a system with a Scroll Compressor. Thanks a lot.
John, so you can usually pump down a scroll compressor but just not into vacuum so I usually stop at 5 to 10 psi. In this video I just meant don't fully pump it down, thanks!
I do not understand a vacuum is quite a good electrical insulator between windings and frame and at a potential of 240v x 1.4 you should be able to pump down to a very low pressure and not cause any shorting out of a scroll compressor, just curious
I’m enjoying your videos! I wish you could come to my house. My new 20 Seer AC has a difference between intake and return vents of only ten degrees or less and the local technicians don’t have a clue so far. I understand it should be at least 15.
There is one thing I heard and kinda confused. You said on a scroll compressor do not pump down bc if you remove the refrigerant it could damage compressor. But if I can’t pump it down then I would have to recover all Freon. If I did that wouldn’t that remove all Freon? And potentially compromise the compressor??
ok watched again. if the low pressure switch fails and txv clogs then we could get a grounded compressor, correct? Do you know at what low pressure the insulating factor of the gas does not work?
My Goodman heat pump has a scroll compressor and I found this in the service manual: "Because of the potential damage to compressors, do not allow suction pressure at service valve to drop below 20 PSIG when pumping unit system down"
And what about the scrolls compressors on a freezer room, or an a walk in coolers, on these systems the condenser unit has to pumps down frequently when the thermostat stop the solenoid valve, and many techs adjust the LPS at zero psig
Quick question on this one as a newbie: could you not flash the refrigerant back in the system? Because you ended up with hoses full of refrigerant there?
A great video, love your content. Just wondering when you pump down a mini split and intend to relocate it with new pipe work do you need to add oil? I am used to car a/c and adding oil when replacing components and pipes. So when moving the unit I will be renewing the pipe work. Many thanks in advance if you choose to answer the question.
Great work. I’m doing this process because I’m moving a customers unit about 10 ft. after I pump it down am I able too cut the line set close to service valves and move the unit???
Thank you for your important information it means alot.???? I ask a question làst week about how long the mini split unit line set can bee and in what occasion u add gas
Each model mini split will have a different line set length that the unit's refrigerant charge will be good for. Look on the outdoor unit rating plate and the installation literature, thanks!
Pub Cat, that is correct. I mentioned before that Scrolls can be pumped down to 5-10 psi unless the manufacturer says not to for that specific model and design. You just don't want to remove the refrigerant completely from the suction side of the compressor which would happen at 0 psi or lower. A pump down system may shut off before 0 psi is reached and therefore leaving refrigerant between the electrical winding and the ground frame, thanks!
Craig I have a tool question. When checking temperature on liquid/suction lines here in Oklahoma where the wind speed is always 15mph, do you find the accuracy of the test instruments could be compromised because of these weather related ambient issues. If so, would a bead probe be better than a Fieldpiece temp clamp?
I have heard people say that about scrolls before. I don’t agree I always pump scrolls down. Actually refrigeration racks for coolers and freezers which are pump down systems by normal operation have scrolls and live that way normally
thanks for this wonderful video, would you consider do a car ac refrigerant tutorial in the future ? comparing to home ac, car has high side, low side and compressor. many similarities. i think many people like me want to see your technical pro explanations. thanks
Yes. Be sure to run it in a/c mode. If you do it by pushing in the contractor manually remember to jump out R to O to make sure it is in a/c. If not it will be in heat
❄🇺🇸🙏👍💪 Great informative vid. Can u pumpdown a refrigeration unit like walkin cooler that has microchannel coils but it also has liquid receiver so unlike ac unit it's not all stored in coils ?
I have a question about the low pressure cut off switch. If you pump the unit with a low pressure switch by pressing the contactor button, will it damage the pressure switch?
What would happen if you pump down a 4 zone mini split system that contains factory charge of 6lbs plus additional .5lbs charge for additional line set? Could the total charge of 6.5lbs exceed the refrigerant storage capacity of the condenser? Would a pump down procedure on this unit cause damage or would you just not get the gauge down to zero? I can't find any info the total refrigerant storage capacity of the condenser. Thanks
Hi , Thank you for your helpful videos. Have a question: I have a AC unit : American Standard Allegiance 13 MFR DATE 2/2006 Mod. No. 2A7A3024A1000Aa Serial no 6055NE65F Can I pump down refrigerant in this unit ?? Thank you.
Hello Craig, big fan of all the video's. I signed up a couple years ago and got your physical bundle of books and charts. I work out of the country and as I am not a certified HVAC tech, The manuals were very helpful. Unfortunately, when my boxes got shipped from one site to another, they lost all my manuals and some other property. That said, I may consider getting the e books this go round when i can afford them. So my actual question is this. Folks at another site disconnected about 60 split pack system and stored them inside the containers. The issue is that none of the line sets or the indoor or outdoor units got the line connection points or the lines themselves covered or closed off from dirt /sand, etc. What do you think would be the best way to purge each unit and the lines sets so as to not ruin everyone by contamination. I have nitrogen available if that could be used and I can order additional dryer filters as well. Trying to save as many as we can. Thank you Mr FiXiT
Mine won't pump down beyond 52. Starts at 225 promptly goes down to 52 and stick there. Changing evaporated coil and have a scroll compressor in case it matters.
Yes it does matter. Many scroll compressors have an internal safety valve that will prevent pump down below a certain point to protect the windings from burning out due to lack of refrigerant which insulates them.
How long should I wait for pump down of different refrigerant? Does the pump down timing varies with capacity and type of refrigerant? I have this doubt for long time. please clarify my doubt.
In this video and on page 143 of your book you talk about taking caution when performing a pump down on scroll compressor because the refrigerant acts as an insulator between the motor windings and ground. Being unencumbered by too much actual knowledge on the subject this statement does not seem logical. I assuming this concept is something that a compressor manufacturer may have stated. Do you recall where or from whom this information was made available to you? It would seem, to the uniformed, that the insulation quality of the motor stator is a function of the coating applied to the magnet wire and not the refrigerant. Can you help me out here?
I disagree with the jumping out the pressure switches. If your tstat is calling, your blower fan is on. If your pressure control opens, just push in the contactor at that point
I thought the same thing. Turn on the blower fan and press in the contactor and avoid the pressure switches altogether rather than call for cooling in the first place. Very useful video though.
Don't Pump Down A Scroll Compressor? Done It Thousands Of Times, Never Had a problem With The Compressor. The Units Come Fully Charged, Never Had Issues With Coils either. but hey do It the "Proper" way if it makes You Happy
@@acservicetechchannel I'm just going to recover the freon then remove it. The customer wants a new unit installed. Once I remove it I'll take it to the shop and check it all out. Either a contactor or capacitor. But it could be something else like the t stat . I'll figure it out. Thanks for the response and have a blessed day
You can pump them down a bit for testing but not down to 0psi or close to that where the refrigerant is no longer at the inlet of the compressor. No less than 10 psi to be safe. Most older scrolls are designed like that, thanks!
@@acservicetechchannel I disagree. I do a lot of refrigeration work that use scroll compressors and many system require a pump down as part of their normal operation. The trick is to know how low you can go and the scroll makers include that information as part of the specs for the compressor. For R-22, 37 psi is typical for other refrigerants like 404a you can go as low as 8 psi and still be safe.
Hi , Thank you for your helpful videos. Have a question: I have a AC unit : American Standard Allegiance 13 MFR DATE 2/2006 Mod. No. 2A7A3024A1000Aa Serial no 6055NE65F Can I pump down refrigerant in this unit ?? Thank you.
Check out our HVAC Calculators at www.acservicetech.com/hvac-calculators
Check out our newest full articles at www.acservicetech.com/articles
Try our new quizzes! Do you have what it takes? www.acservicetech.com/quizzes
My Paperback, Workbook, Cards and E-Book: www.acservicetech.com/the-book
My Paperback, Workbook, Cards: www.amazon.com/shop/acservicetech
Support the Channel: www.patreon.com/acservicetech
Tool List: www.amazon.com/shop/acservicetech
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) ua-cam.com/users/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.
You are a great technician 💯
Glad you enjoyed it!
I would like to extend my warmest thanks to you and your family, wish you and your family happy life.
You are so kind
Good presentation. I am retired, this would be useful for a young tech
Thanks a lot Bob!
Great job, made it easy to catch.
Did not know about jumping the pressure switches... Why was I never told this. Thank you sir.
Why jump it out? When it goes off on low pressure, you can just push your contactor in. To me that's more to my benefit cause i don't have to pull the disconnect to stop it, just let go of the contactor plunger
It is just something to watch out for if running the system in ac mode. I highly encourage techs to have the indoor fan running during the pump down. This way, the pressure does not rise after the pump down process is complete due to vaporization, thanks!
By the book!!!! Done properly. Thanks for those informative videos!
Awesome! Thank you!
Always good to have a refresher 💯🙌
I've been doing this for 30 years and I thought to myself I don't need to watch this what am I gonna learn and then I thought no I might learn something and I did Micro channel I had no idea that you couldn't pump it down on microchannel
Thanks Russell!
Do you have a video on pumping down a mini split?
this one helped me visualize the process and understand what's going on big thanks!
Great stuff, Craig. With respect to pump down videos in general…I think it’s important to reiterate that outdoor condensing units do not have endless refrigerant storage capacity. Despite countless videos showing someone closing the LL, holding in the contactor, closing the SL, etc…and viola! Firstly, your professional recommendation (safer I'll add) is much better. Secondly, well, some times/often it doesn’t work so easily. Depending on evaporator size, lineset specs, etc. even brand new compressors will trip their pressure relief during pump down-puzzling many (here assuming limit switches were bypassed). In these cases, you trap what you can get and evac the rest. My point is IF you think you’re going to always conveniently ‘pump down’ every system into its ODCU, you’re mistaken. I’ve had brand new units pump down to around 225 psig on the LL and that’s it.
Great instruction Craig. In previous pump down videos you have advised that due to the insulating properties of the refrigerant in scroll compressors not to pump down to a vacuum, but only go down to 5 LBS psig. In this video you advise NOT to pump down systems with Scroll Compressors. Please explain the change. Also, please do a video on just how you now would pump down/evacuate a system with a Scroll Compressor. Thanks a lot.
John, so you can usually pump down a scroll compressor but just not into vacuum so I usually stop at 5 to 10 psi. In this video I just meant don't fully pump it down, thanks!
Thanks Craig. Appreciate the quick reply.
Was a video ever made?
I do not understand a vacuum is quite a good electrical insulator between windings and frame and at a potential of 240v x 1.4 you should be able to pump down to a very low pressure and not cause any shorting out of a scroll compressor, just curious
Thank you. I will buy your book.
Thanks and check out the 1,000 reviews of it on amazon. We have the paperback, workbook, and cards as a set at our website, thanks!
I’m enjoying your videos! I wish you could come to my house. My new 20 Seer AC has a difference between intake and return vents of only ten degrees or less and the local technicians don’t have a clue so far. I understand it should be at least 15.
There is one thing I heard and kinda confused. You said on a scroll compressor do not pump down bc if you remove the refrigerant it could damage compressor. But if I can’t pump it down then I would have to recover all Freon. If I did that wouldn’t that remove all Freon? And potentially compromise the compressor??
Very clear and informative 👍🏾👏🏾
Thanks piz11!
ok watched again. if the low pressure switch fails and txv clogs then we could get a grounded compressor, correct? Do you know at what low pressure the insulating factor of the gas does not work?
Good question.
My Goodman heat pump has a scroll compressor and I found this in the service manual:
"Because of the potential damage to
compressors, do not allow suction pressure at service valve
to drop below 20 PSIG when pumping unit system down"
I use the bump the contactor method. Pull 24 volts off contactor or turn the thermostat off.
That works too for shutting the system off. I just like to pull the disconnect as the safest quickest method, thanks!
And what about the scrolls compressors on a freezer room, or an a walk in coolers, on these systems the condenser unit has to pumps down frequently when the thermostat stop the solenoid valve, and many techs adjust the LPS at zero psig
Quick question on this one as a newbie: could you not flash the refrigerant back in the system? Because you ended up with hoses full of refrigerant there?
Craig do you have a video on how to pump down a multi-port mini splits?
Awesome video buddy love it very helpful 👍👍
A great video, love your content. Just wondering when you pump down a mini split and intend to relocate it with new pipe work do you need to add oil? I am used to car a/c and adding oil when replacing components and pipes. So when moving the unit I will be renewing the pipe work. Many thanks in advance if you choose to answer the question.
Great work. I’m doing this process because I’m moving a customers unit about 10 ft. after I pump it down am I able too cut the line set close to service valves and move the unit???
This is good stuff
Thank you for your important information it means alot.???? I ask a question làst week about how long the mini split unit line set can bee and in what occasion u add gas
Each model mini split will have a different line set length that the unit's refrigerant charge will be good for. Look on the outdoor unit rating plate and the installation literature, thanks!
As he said it different for different ones but a Mitsubishi mini split said on the outdoor unit anything over 98 feet of liquid line add x amount.
Nice job!
Thanks for the visit
Great vid and great book!
Question about scrolls, I heard you can pump them down just not below like 5-10psi?
I wanna know this too
Following. Everything I have heard is don’t do it.
I always pump scrolls down. Actually refrigeration racks for coolers and freezers which are pump down systems by normal operation have scrolls
@@drodriguez394 I’ve always pumped down scrolls, never had a single issue
Pub Cat, that is correct. I mentioned before that Scrolls can be pumped down to 5-10 psi unless the manufacturer says not to for that specific model and design. You just don't want to remove the refrigerant completely from the suction side of the compressor which would happen at 0 psi or lower. A pump down system may shut off before 0 psi is reached and therefore leaving refrigerant between the electrical winding and the ground frame, thanks!
awesome Craig!!!! hey, Craig do you have any videos on package units? thank you for sharing.
Craig I have a tool question. When checking temperature on liquid/suction lines here in Oklahoma where the wind speed is always 15mph, do you find the accuracy of the test instruments could be compromised because of these weather related ambient issues. If so, would a bead probe be better than a Fieldpiece temp clamp?
I have heard people say that about scrolls before. I don’t agree I always pump scrolls down. Actually refrigeration racks for coolers and freezers which are pump down systems by normal operation have scrolls and live that way normally
What pressure is the cutoff set for on the low pressure switch? Thanks!
Which line do you open first after you pump down for a stuck schrader repair?
thanks for this wonderful video, would you consider do a car ac refrigerant tutorial in the future ? comparing to home ac, car has high side, low side and compressor. many similarities. i think many people like me want to see your technical pro explanations. thanks
it is the same process for a heat pump ? Thank you
Yes. Be sure to run it in a/c mode. If you do it by pushing in the contractor manually remember to jump out R to O to make sure it is in a/c. If not it will be in heat
@@williamserver4332 thank you
Tito, same exact thing as in the video. Just jump the pressure switches and turn the thermostat in air conditioning mode, thanks!
@@acservicetechchannel thank you 👍🏻
❄🇺🇸🙏👍💪 Great informative vid. Can u pumpdown a refrigeration unit like walkin cooler that has microchannel coils but it also has liquid receiver so unlike ac unit it's not all stored in coils ?
Great method
Thank you!
I have a question about the low pressure cut off switch. If you pump the unit with a low pressure switch by pressing the contactor button, will it damage the pressure switch?
What would happen if you pump down a 4 zone mini split system that contains factory charge of 6lbs plus additional .5lbs charge for additional line set? Could the total charge of 6.5lbs exceed the refrigerant storage capacity of the condenser? Would a pump down procedure on this unit cause damage or would you just not get the gauge down to zero? I can't find any info the total refrigerant storage capacity of the condenser. Thanks
Hi , Thank you for your helpful videos. Have a question:
I have a AC unit :
American Standard
Allegiance 13
MFR DATE 2/2006
Mod. No. 2A7A3024A1000Aa
Serial no 6055NE65F
Can I pump down refrigerant in this unit ??
Thank you.
Hello Craig, big fan of all the video's. I signed up a couple years ago and got your physical bundle of books and charts. I work out of the country and as I am not a certified HVAC tech, The manuals were very helpful. Unfortunately, when my boxes got shipped from one site to another, they lost all my manuals and some other property. That said, I may consider getting the e books this go round when i can afford them. So my actual question is this. Folks at another site disconnected about 60 split pack system and stored them inside the containers. The issue is that none of the line sets or the indoor or outdoor units got the line connection points or the lines themselves covered or closed off from dirt /sand, etc. What do you think would be the best way to purge each unit and the lines sets so as to not ruin everyone by contamination. I have nitrogen available if that could be used and I can order additional dryer filters as well. Trying to save as many as we can.
Thank you
Mr FiXiT
Great tech 👍🏻
Thanks Jonny!
Mine won't pump down beyond 52. Starts at 225 promptly goes down to 52 and stick there. Changing evaporated coil and have a scroll compressor in case it matters.
Yes it does matter. Many scroll compressors have an internal safety valve that will prevent pump down below a certain point to protect the windings from burning out due to lack of refrigerant which insulates them.
How long should I wait for pump down of different refrigerant? Does the pump down timing varies with capacity and type of refrigerant? I have this doubt for long time. please clarify my doubt.
Just follow your pressure gauges , that way you know how much refrigerant u have inside the unit
Can you pump down R410a?
Can I pump down inverter compressor?
can ac unit be pumped down when it's cold outside?
Can you please make a superheated charging chart with degrees Celsius. Please this will mean a lot
thank you teacher
Glad to help!
how can you claim that we cant pump down the rotary compressor ?
Rotary compressors can pump down. I believe I only mentioned reciprocating and scrolls, thanks
What an price in you are use vaccuum pump set pro sir?
Is there a reason why I never see a heat pump pumped down in heat mode?
In this video and on page 143 of your book you talk about taking caution when performing a pump down on scroll compressor because the refrigerant acts as an insulator between the motor windings and ground. Being unencumbered by too much actual knowledge on the subject this statement does not seem logical. I assuming this concept is something that a compressor manufacturer may have stated. Do you recall where or from whom this information was made available to you? It would seem, to the uniformed, that the insulation quality of the motor stator is a function of the coating applied to the magnet wire and not the refrigerant. Can you help me out here?
Each video I watch... I get more information.. filtering out the bad information from some..
Best video
Glad you enjoyed it!
I disagree with the jumping out the pressure switches. If your tstat is calling, your blower fan is on. If your pressure control opens, just push in the contactor at that point
I thought the same thing. Turn on the blower fan and press in the contactor and avoid the pressure switches altogether rather than call for cooling in the first place.
Very useful video though.
Szuper! Köszönöm!
Hi bro this books free on online available???
They are for sale on our website www.acservicetech.com/store on amazon, google play, and apple book store, thanks!
Don't Pump Down A Scroll Compressor? Done It Thousands Of Times, Never Had a problem With The Compressor. The Units Come Fully Charged, Never Had Issues With Coils either. but hey do It the "Proper" way if it makes You Happy
What if the unit doesn't turn for a pump down
There is something wrong that needs to be fixed if its not turning on in air conditioning mode.
@@acservicetechchannel I'm just going to recover the freon then remove it. The customer wants a new unit installed. Once I remove it I'll take it to the shop and check it all out. Either a contactor or capacitor. But it could be something else like the t stat . I'll figure it out. Thanks for the response and have a blessed day
👍
Thanks!
Wait till craig find out that I push the contactor in on systems with a scroll compressor 😵💫
We still do a partial pump down for testing if a scroll compressor is good and the internal pressure relief is good, thanks!
🥃😎🍺👍🏻
Thanks!!!
I have never head that you can't pump down a scroll compressor for the reason that you just said. I am looking online for more info.
You can pump them down a bit for testing but not down to 0psi or close to that where the refrigerant is no longer at the inlet of the compressor. No less than 10 psi to be safe. Most older scrolls are designed like that, thanks!
@@acservicetechchannel I disagree. I do a lot of refrigeration work that use scroll compressors and many system require a pump down as part of their normal operation. The trick is to know how low you can go and the scroll makers include that information as part of the specs for the compressor. For R-22, 37 psi is typical for other refrigerants like 404a you can go as low as 8 psi and still be safe.
Hi , Thank you for your helpful videos. Have a question:
I have a AC unit :
American Standard
Allegiance 13
MFR DATE 2/2006
Mod. No. 2A7A3024A1000Aa
Serial no 6055NE65F
Can I pump down refrigerant in this unit ??
Thank you.