Tool List- www.amazon.com/shop/acservicetech Support- www.patreon.com/acservicetech For those that are looking for the tools used in the videos: (Linked Below) Here is the Link for the Yellow Jacket Refrigerant Manifold Gauge Set used in the videos- amzn.to/2aenwTq Here is a link to Refrigerant hoses with valves used in the videos- amzn.to/2aBumVI Here is a link to the UEI DL389 Multimeter used in the videos- amzn.to/2xAdaJf Here is a link to the Imperial 535-C Kwik Charge Vaporizer for Charging Refrigerant- amzn.to/2wFHtBW Here is the link to the Fieldpiece ST4 Dual Temp Meter- amzn.to/2wc1ME3 Here is a link to the Digital Refrigerant Scale used in the videos- amzn.to/2b9oXYl Here is a link for RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn Other tool links can be found in the video description section. ACSERVICETECH is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon. Check out other videos on the HVACR topics of interest at- th-cam.com/channels/OZR-1IqsAer9wzlvFgb4mA.htmlplaylists?view_as=public If you want to support the ACSERVICETECH Channel and receive more HVAC content, check out www.Patreon.com/acservicetech
*So amazingly quiet and **Fastly.Cool** in my room! 42db is at a whisper level. I bought 2 and installed myself.Very sturdy bracket and easy to adjust to fit windows of different size. Absolutely fabulous units!!*
Hi. I just wanted to provide you with a quick update. I installed, pressure tested and charged both of my mini-splits as per your directions "however followed the manufactures specs for weighing in additional refrigerant" as I had more than a 25 ft lineset. So far everything is working great. Not sure what your take is on this but I would recommend people buy a cheap leak detector and use nylog on their flare connections. The leak detector found a minuscule leak on one of the connections I didn't use nylog on. Leak detector was about "50$ on amazon". Even after using a torque wrench/crow foot fitting with the proper torques on it and pulling a vacuum down below 500 microns the leak detector detected a minuscule leak on one of my flare connections. I added an additional 1 ft/lbs and that seemed to do the trick. For the second system I used nylog on the flare connections. It seems to be cheap insurance against system leaks. I did pre-charge both systems with nitrogen to pressure test prior to allowing the refrigerant into the system. I was able to pull a vacuum down to 230 microns on each system and it held after 5 minutes. . The nylog really seems to act as a lubricant when torquing the flare nuts. Thanks again for all your helpful videos and if someone is considering using nylog make sure you buy the right one for your refrigerant application as they make at least 2 types that I'm aware of.
Yes the blue is for hfc's and the red is for cfc and hcfc's. It seems to work well. Starting in the field we always used the same refrig oil that was in system on the flare seat. This seemed to do the trick. Almost anytime I have seen someone not put oil or nylog then there is a leak. Thanks for your detail!
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Nice video. Good explanation of how to charge a mini split system, however, I think you may have forgotten to multiple the 20.92 times 1.08 which gives you more like 22.6oz. I know its not a big difference and maybe you just figured the .08 extra per five feet wouldn't make the much of a difference. What do you think?
You are absolutely right. It was a hot one and I did my calculations on another sheet. I do however put a little over on the mini splits by shutting the tank down and weighing in the liquid that is left in the yellow service hose into the service hose. It will be very close, good catch and thank you for your very nice question. Thanks for your comment!
No problem. Thanks for replying. We've all been there on those hot days. I installed that same outdoor unit on my own house last year. It is a good unit and much more efficient than my old 10 seer York central unit. Just subbed you today and have watched a few of your videos. You do a good job explaining what you are doing. Very helpful!
3 years later im another one to actually follow the math lol. Thank you for the vids and info sharing peoples. Hope all is great. How are the systems doing?
Thanks great video, especially as I am about install exactly the same make and model. You have clarifed for me if I need to add more refrigeration as the instructions are contradictory. Just one question, when you say the liquid line length do you just mean the 1/4" line length not the 1/2" vapor line as well? Thanks for your your help.
Excellent video - detailed and concise. Questions. The 21 oz weighed includes refrigerant in the suction hose. So how does one get those few to several ounces into the system or do you (after video ends) add a few more ounces to account for hose amount? Prior comment on use of low-loss fitting at the suction line port was also on my mind. Thanks
If you purge your hoses of air and then zero out your scale you get the exact amount of refrigerant in the system .......There would be a small amount left in the hoses which if you added to the system would put you over the additional amount... is let out into the atmosphere under the di minimus law
I did charge what was in the yellow service hose into the system. If it were adding refrigerant to a system during a superheat or subcooling process you would or could shut the bottle down and continue to charge what is left in the yellow service hose into the system while monitoring superheat or subcooling to make sure that you don't put too much refrigerant in. This would get rid of the refrigerant in the hoses for you. With minisplits I do usually put the yellow service hose's refrigerant into the system or I will stop short an ounce or so and add this in. Thank you Zeke112964 and Papa Joe for your Comments!
If it is a standard compressor then yes but if it is an inverter system then you need to charge by weight. Always check the manufacturers rating plate or on the inside of the service door for directions, thanks!
if I am using only 2 zones and a total of 30ft line sets do I need to recover the rest of the factory precharge refrigerant? or not? I have the exact same unit. Thank you!
In an instant where you don't know the amount in the minisplit unit due to a flare leak, do you personally reuse the recovered refrigerant and then add additional or just use virgin refrigerant on the recharge? Thanks in advance. BTW... I FINALLY order all of your material. It only took a year! :~) -Brian
very good video, i install 1 zone mini's never a 2 plus zone... if you could invent a board that would maintain a constant run for the fan invertor just for the mini splits preventing having to reweigh in a charge, you'd be a rich man
Thanks and glad you are enjoying the Channel there in Canada! How is the weather up there presently in terms of temp and humidity with people needing emergency service?
Thanks for these extremely helpful videos. AC companies in my area won't even return your call as they are all too busy and frankly they just don't care as business is booming. I've decided to tackle my mini-split install myself. I'm finding it expensive however to buy all the proper gear for the install. If I pull a vacuum down to 500 microns is it safe to say I have no leaks in the system and don't have to pressure test with nitrogen? Buying the nitrogen tank is expensive and I won't be brazing anything. I did buy the flare tools etc.. Thanks.
One more question. Once I pull the vacuum how do I reconnect the charge hose from the vacuum pump to the refrigerant tank without introducing air into the system? Thanks again..
Up here in Alberta its been a hot summer for us. As we are in celcius our summer was consistantly 24-30º c with high humidity. Our seasons are different with you guys down south as summers is AC season and we sell, service and repair like you but generally speaking if someones AC system goes down it is not considered an emergency unless of course its a business. But come fall and winter where we usually average around -15ºc and some spells of -30º+, if someones heat goes down we go aroound the clock with emergency no heats. Probably like you, I love the emergency calls...good money :) Keep up the good videos...I really enjoy them. Cheers
Where I am located at by the shore, we have a lot of summer tourist activity and that would be considered business service calls to us. We have to go as if it's a no heat call in the winter. I am glad you are enjoying the videos! I will transition to preventative maintenance and gas line videos likely in between seasons and start making furnace and heat pump videos. Thanks and have fun!
Great videos. Enjoying very much. Thanks for sharing your knowledge. I'd like to ask a questions: Apart from refrigerant charging, when do we have to take care for the compressor oils? Does the refrigerant charging containers contain the compressor oils, as well? And since I live in Europe where mini splits are very popular, what kind of care do they need regarding their (mini split's) compressor oils. Again, thanks for the great job.
Great Question! So the outdoor units always come with oil from the start, even systems that are considered dry without refrigerant do have the oil in them already unless the manufacturer states it does not in some weird circumstance but any one that I am familiar with will have it already. The oil is miscible and will travel with the refrigerant throughout the system and through the vapor compressor. The only care that is needed in regards to oil is to make sure that you are not introducing moisture into the system via the your service hoses. You should also make sure that you have a good vacuum on the system that holds 500 microns or better before allowing the refrigerant from the outdoor unit to the lineset and wall units upon initial installation. The oil will last as long as the system does and will not need to be changed. Thanks
Have you done any videos where you charge from zero? So vacuum both sides of the service valves and add the whole amount of refrigerant. How much will go in before you have to turn on the unit
Next time i recommend planning it all out and thinking like someone that does not already know how to do this. I wrote technical manuals for over 20 years, and there are dozens of steps and assumptions made here that someone like me, trying to do what you are doing, has virtually zero chance of success.
They limit the superheat down to a ery small amount typically 0-5 degrees when on max cool. This is for the extra efficiency and also since they have an accumulator for compressor safety. I wish they would put the numbers out there when at a specif speed but they don't. Subcooling isn't read since there isn't a port. You could read it with just temp sensors though. Subcooling and superheat will change when the system is ramping up or down depending on how many head units inside are running. Thanks
Johnmiller102 go to mylinkdrive.com is a Mitsubishi web page the have videos explaining the hole process and flow of refrigerant from the simplest mini split all the way to vrvs and vrfs you will be amazed the amount of information is in this web page
4:17 it will not "take the average". First-order approximation/model: pressure is equal to lowest temperature saturated vapour pressure in the line set. Some parts of pipe may have super-heated vapour. No parts of pipe may have "sub-cooled vapour". Refrigerant migrates to the lowest temp. location and the liquid-vapour equilibrium P/T values in this location are decisive.
I just recovered 2 similar units that were installed briefly then decommissioned because the plant they were in has airflow problems and all the air these units made was sucked up and out the through the roof, and did not solve their problems. The wall units had already been discarded but because the refrigerant hadn't been recovered yet they were storing the condensers. I have a shopping list made up with wall units, line sets, and disconnect boxes. I am a millwright by trade but mostly work on air compressors. I plan on installing them for my home myself, with the help of an electrician for setting up my disconnect boxes and HVAC tech to purge, vacuum test, and charge my system. Is there anything in particular about these units that I should know? Someone online mentioned Mitsubishis can be tricky to wire but based on the manual it doesn't look any different than your complete install video I watched the other day, other than having to wire 3 separate units vs the one in your video. PS, you aren't related to Seth's Bike Hacks are you? Same NJ accent and talent for video production
can I ask what is the correct operating pressure ( blue ) - low line - for this exact type of Mitsubishi ? i have exactly the same 4 zone system and want to check if it is overcharged ?
Hi I’ve recently installed a Fujitsu AOU36RLXB It comes precharged with 4lbs 10oz. Of 410a from the factory, which is rated for 66ft according to the manual. It states that if the line length is below 66’ no additional charge needs to be added. I only used about 20’ of line between the outdoor unit and the indoor unit. In this situation do I leave the precharge from the manufacturer as is? Or do I have to recover some refrigerant. Thank you!
Do I vaccum the zones on at a time? If so would I get any air sucked in when I remove the blue hose to do the vac the next zone or is there a valve to use to vac all the zone lines at the same time? Thanks for your great vid👍
about to install this same unit. why does the install manual say that it only comes charged with 25ft worth yet on the unit itself says to add if more than 98 ft?
Nice work man .. I am new in this matter, but I have understood that mini splits are like piston expansion.. my question is related the way it was charged the unit.. Can I charge by superheat instead of by weighting the refrigerant? Thanks in advance
If the mini-split is an inverter style than you must charge by weight only because it ramps up or down and there is not a steady superheat or subcooling. Thanks for the question!
There is a trick you can use to get them by for a short time if it's really busy or a holiday weekend. You set the indoor units to cool and push the Emergency Operation buttons all of the units. That puts the whole system into high cool regardless of the indoor and outdoor temps. Mitsubishi says the saturation TEMPERATURE on the vapor side should be between 45-50deg F. Add refrigerant until you're in that range and it will cool quite well until you have a chance to go back and find the leak and repair it, then recover and properly weigh in the charge. You'll find that the amount you took out will be pretty close to the amount that you have to put back in
so if the factory charge is good for 98 feet and say you only use 50 feet they dont require you to recover any? so that tells me that these systems are more tolerant of being over charged. Or am I missing something? Is this because mini splits have an accumulator? just trying to understand, im new to this but trying to learn.
I have a mini split with 2 indoor units. At the outdoor compressor unit I see there are four lines and 2 lines with service valves. Which service valve should I connect to? Or doesn’t it matter. Thanks!
If one were to install a multi zone unit as shown in this video, and added an additional air handler to the multi zone compressor down the road, would connecting the new air handler line sets cause any loss of refrigerant? And how would one test the newly installed line sets for leaks, again without losing refrigerant? Please forgive if my question is absurd, as I am not an HVAC pro.
Yes it would as there is only a vapor service port for you to pull a vacuum from which is connected to all the rest of the indoor wall units. You would have to pump down the system and/recover the refrigerant, pressure test the linesets, vacuum pump the system along with the new lines and indoor unit and weigh in the refrigerant accordingly, thanks
That unit said to add a certain amount of ounces for every 5' of lineset added past the maximum length of lineset for refrigerant that came with the unit, thanks
Very good video, will you be more videos on mini-split units. Just started getting into a/c and installing Fujitsu Mini-Splits. In there info on unit say it needs a minimum of 16' of lineset, wondering how it shows on gauges if run is less than 16', and if it will affect unit. Thanks
You would need to recover the refrigerant if it is less than that because the accumulator may not have enough room to stop the extra refrigerant from making it into the compressor as a liquid during some of the run times. Thanks for letting me know what you would like to see!
Sitting on a roof. Staring at a MXZ-C030NA Mitsubishi 3 zone. Really used to doing refrigeration Subcooling. What the general recommended number for these inverters? I know it’s really too high at 43.2 460 psi high side and temp 85 degrees which gives a condenser Tsat 128. Temp outside is 74 & raining.
I followed your TH-cam channel very informative. I believed all this Inverter units are pre-charged by the manufacturer. But I didnt get how much LINE set in ft.?? for the specific pre-charged, then you add if you get over the line set I get that. Am I missing something in this videos.
Each unit will state on the rating plate up to how much lineset can be used for the amount of refrigerant in the unit. These lineset lengths will be different on different model numbers or sizes, thanks
My unit has a max capacity of 128 oz so 8 lbs how do I go about knowing how much lbs it already has inside the unit? Should I just add 2 lbs to be on the safe side
Hi Can you please help with mxz-8c48na My question is should I change outdoor unit thru service port low side or charging port low side? Thank you in advance
Thanks for making this video! I'm getting ready to install a Pioneer split mini, and it calls for 0.16 oz per additional foot. It comes charged for 16', and my run is 50', so I believe I need to add 5.44 oz. Do I have to charge with the tank upside down? I may just use the additional charge to break the vacuum. That seems like the easiest way to do it. I wonder if it will pull in 5.44 oz. Do I need to do it a little at a time if the system isn't running?
As long as you are EPA 608 certified, If it is R410a then it has to come out of the bottle as a liquid (upside down in disposable bottle). If you are breaking the vacuum then it gets weighed in as a liquid. Make sure to use a hose with a valve on the end and purge the air out to that point and then connect to the port, then zero the scale out, thanks
Do those multi indoor systems have the expansion valves at the evaporators and uses true “liquid” lines? I know the singles have the expansion valve in the condenser and your line set is an extension of the evaporator and that’s why both lines are insulated.
Hi I’ve just installed a Fujitsu multizone 4 head system and used 3 line sets of 50’ and took out about 10’. Do i Measure each line set as a 50’or 100’ since you have liquid line and suction line so is it 150 ’total or 300’ total. Maximum line to be used it says 163feet. Thanks
I have an LG 3 zone mini slipt just checked the gas line on my low line and its reading 290 while all 3 zone are running i have 100 ft of line set system has 3.97 lbs of r410 at 73.8 ft i need to add 8 oz to top off why is my low pressure hose st 290 i though I needed to add more refrigerant my handler unit temperature is 57 degrees should it be lower thanks
thank you now i understand. but for example the one i have is daikin mini split inverter 12k btu and i need to add .16907 oz for every 5 additional feet. so using your same calculations. 20.92 * .16907 = 3.53 oz of refrigerants. when comparing mine to yours, isn't 3.53 oz a bit low?
You would look at your daikin and see how much they want you to add for every additional 5' or 1' and add up all your lineset lengths to add more than what the unit came with. If it was a leak then you would recover, fix leak, pressure test, vacuum, weigh in initial amount plus any additional feet, thanks
hi, so if you had check for proper refrigerant level how would you do it if we're not measuring superheat or sub cooling? i mean just looking at the gauge how'd i know if i have the correct charge? thank you.
You may not but just from experience on systems that know had the correct charge, the superheat was 0 to 5 degrees on the vrf minisplit systems I have been installing and the accumulator protects the compressor during low superheat, thanks
Is there a way to vacuum without gauges.I remove Schafer core but I can’t attach my micron gauge due to the port been so close to unit any suggestions?
I just worked on one of these for the first time and have a question. I noticed that tag on that small line to the left said it is where you should charge it. Why did you hook up to to the big line to charge yours?
Thanks for these extremely helpful videos. AC companies in my area won't even return your call as they are all too busy and frankly they just don't care as business is booming. I've decided to tackle my mini-split install myself. I'm finding it expensive however to buy all the proper gear for the install. If I pull a vacuum down to 500 microns is it safe to say I have no leaks in the system and don't have to pressure test with nitrogen? Also once I pull the vacuum how do I reconnect the charge hose from the vacuum pump to the refrigerant tank without introducing air into the system?
Ok just saw your other video on weighing in refrigerant. Noticed you have a shutoff valve at the end of the hose to prevent air being introduced into the charge line. Thanks again...
Yes if you didn't have the valve then you could just vent the air out of the top at the gauge manifold until it was just refrigerant in the hose. When I am switching from vacuum to charging I close the gauge set also before disconnecting the micron gauge.
Great Question! If the lines were bigger in diameter and you had a 3cfm pump then I would say it is likely that you don't have a leak but I always pressure test. It really also depends on how big your vac pump is and where you place the micron gauge. You can check out this video. th-cam.com/video/nBCWYgCcnpE/w-d-xo.html
Thanks again for sharing your knowledge. You're helping thousands of people and your videos are some of the best instructional videos I've come across. I'll be placing my order with amazon using your embedded link. You may want to publicise the link in all your videos as I stumbled across it. I'm sure people will be more than happy to support you any way they can.
When the ductless mini split needs to be charged we cant use the low side to charge it? we have to go through accumulator? Also how do you pump down a fujitsu or mitsubishi mini split unit.
If it is running, the low side will flow through into the accumulator, we are just weighing it in. You would still watch the vapor gauge, shut the liquid service valve, and then shut the vapor service valve when it gets low enough. Thanks
I have to add a couple ounces of R410A to a Mitsubishi H2I 6,000 btu unit, 35 ft line set (10 ft over pre charge limit). How do I get the air out of the manifold and hoses, I assume that's what you mean when you say "get the air out". Do I pull a vacuum on the manifold and hoses and then attach the hose to the service port and refrigerant? I've already released the pre-charge into the system.
Well if you did a repair, say on the compressor or solenoid valves you could go ahead and braze a 1/8" access valve onto the liquid line inside under the outdoor unit cover. The unit also has an accumulator and the last time I talked to a Mitsubishi tech they said it was normal to have 0-5 degrees of superheat while running on full emergency cool on all indoor units. My question was isn't that going to damage the compressor if you don't have superheat? The tech on the phone said that they are safe even when running at 0 superheat because of their accumulator. We know accumulators have their own metering device so at least it is at saturated state but mainly vapor. To be extra safe you could braze an access fitting right in the side of the liquid line under the cover. Remember that they design these specifically so that people don't try to charge them in subcooling. They also design them to have flares so that the torch doesn't touch the lines. The problem is not the torch but that many are not running the nitrogen through and the manufacturers don't want the blame of all that oxidation clogging things up. Most of the refrigerant from a system that says you can have up to 125' of lineset when you only have 30' is just sitting in that accumulator so technically it would have to go there before going to the compressor. To be sure, check with the manufacturer themselves at tech support to be sure of their recommended procedure. Thanks
Thanks for the quick response. I have a daikin rxs24dvju that is over 9 years old and hasn't been running for about 2 years now. I believe all the gas has just leaked out of the flare probably because it wasn't bolted down and people would bump and sit on the outside unit. So I tightened it up and pulled a vacuum on the whole system and it seems to be holding. However with no gas and only a low side service port I'm not sure how to weigh in. I don't really want to put to much money into it as it might not be worth it and im not sure i'm experienced enough to braze a 1/8" access valve into the liquid line. Would it be completely wrong to sip in r410a through the low port while the unit is off and under vacuum? Or should I turn the unit on and try to sip almost 4lbs of r410a in through the low port? I imagine the high and low valves remain completely open while charging?
You would still need to get about 2-3lbs at the very minimum in before starting it so the evaps don't all freeze and you have some refrigerant to work with. If that is the case not much difference between that and the 4lbs it needs. You could call tech support for Daikin. It is certainly different than a standard condensor because of the accumulator. See what Daikin says. It won't hurt. It sounds like you know what you are talking about and they should give you the info you need. Thanks
Would such a "vacuum/charge valve" from Yellow Jacket help when connected to the high side? Would it provide an access port to mini split's high side without soldering? (I mean the left valve which is depicted in the following link) yellowjacket.com/product/vacuum-charge-valve/
There is no need to have a valve on the high side with a variable refrigerant flow unit. Mitsubishi just wants us to weigh the charge in. The tech support stated that a superheat of 0-5 degrees would work when on full emerg cooling on all units and I have checked some of my installations and they range from 2-4 degrees of superheat when it is 70 degrees or higher out. Thanks
When they mention to add refrigerant per every 5 ft of line set, what if you only use 3 indoor heads on a 4 zone system? Is there anything change when only using 3 heads instead of 4 heads? Thank you.
It is cumulative lineset not just to one head unit. They get added together. Also make sure that your system can handle one less communication wise and that you are using the capacity of the system properly by verifying in the manufacturer's literature, thanks!
I have a multi-zone mini split. But one of the unit begin to frost when the unit is off while another room is running. Is the that is off low on charge?
Companies install certain brands because they feel that they can get service parts for them faster. There are a lot of good units manufactured by different companies. Thanks for your Comment!
Yes you can overfill. That's our problem as we do not know how much refrigerant is in it if we suspect a leak and thats why we have to recover and start over if there was a decent leak, thanks
Thanks for the info. Another question. Today I replaced an evaporator on a mini split LG. I got a good vacuum and charged the system by weight based on the specs. When I started it up, I was getting some frost on the valve of the "liquid" line (quarter inch line). Is it normal to have a little frost there? It seems that maybe its low on refrigerant, but I weighed it in...not sure what to do. I do not have excessive line set. Only have about 10' total.
Usually there is not. So check to see if you have the system on max cooling, see if you have 1-5 degrees of superheat. If you have a higher superheat then it may still be low. Also check to make sure that you have 19-22 degree temp decrease across the indoor evap coil. If you have less then maybe you are low. Is it possible that the scale was somehow not measuring correctly? thanks
I had to cut my line set prob about 12 or 14 inches from the factory length am I ganna have to evacuate some refridgent or do you think I'll be ok if that's the case I'll prob just get another factory size lineset so I dont have to mess with evacuation some ...any info will be highly appreciated
I need to charge back in the factory charge after a line leaked the original factory charge out, is there any way I can add it as liquid into the service valve which would be the high side while the system is in heat pump mode? and then finalize the charge using a quick charge gas adapter via low side in cooling mode while running? Or is the only way to weigh in 8 pounds and 13 ounces to the low side while the unit is running in cool mode? @acservicetechllc
Loose, if the system is empty of refrigerant, pressure test the system with nitrogen under the max design pressure of the unit, release the nitrogen, vacuum the unit below 500 microns, perform the standing vacuum test to see if you are holding a vacuum. if it stays below 500 microns, weigh the correct amount of liquid refrigerant as stated on the rating plate and as needed by the cumulative length of the line set into the liquid line if there is one inside the unit, otherwise weigh it into the low side if that is the only port. the system is off this whole time. Give the refrigerant some time to saturate and circulate while the system is off, then after 20 minutes, go ahead and turn the system on. Make sure you are EPA 608 certified before buying or handling refrigerants, thanks Loose!
Just came across a mini split at a job we were at and I noticed the liquid line is very cold. Condenser is blowing warm air and there is condensation coming out of line. Is this normal operation with these mini splits? Thanks
acservicetech We were just there to silicon where the the line set came through and my lead mentioned that the crew that originally installed it had lost a lot of refrigerant from the flare nut when they were tighten it down. He said they replaced refrigerant but when I felt the liquid line I thought that maybe it was low on charge so that's why it felt so cold. I haven't really done a mini split yet so I don't know a whole lot about them. Thanks for the reply.
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*So amazingly quiet and **Fastly.Cool** in my room! 42db is at a whisper level. I bought 2 and installed myself.Very sturdy bracket and easy to adjust to fit windows of different size. Absolutely fabulous units!!*
Hi. I just wanted to provide you with a quick update. I installed, pressure tested and charged both of my mini-splits as per your directions "however followed the manufactures specs for weighing in additional refrigerant" as I had more than a 25 ft lineset. So far everything is working great. Not sure what your take is on this but I would recommend people buy a cheap leak detector and use nylog on their flare connections. The leak detector found a minuscule leak on one of the connections I didn't use nylog on. Leak detector was about "50$ on amazon". Even after using a torque wrench/crow foot fitting with the proper torques on it and pulling a vacuum down below 500 microns the leak detector detected a minuscule leak on one of my flare connections. I added an additional 1 ft/lbs and that seemed to do the trick.
For the second system I used nylog on the flare connections. It seems to be cheap insurance against system leaks. I did pre-charge both systems with nitrogen to pressure test prior to allowing the refrigerant into the system. I was able to pull a vacuum down to 230 microns on each system and it held after 5 minutes. .
The nylog really seems to act as a lubricant when torquing the flare nuts.
Thanks again for all your helpful videos and if someone is considering using nylog make sure you buy the right one for your refrigerant application as they make at least 2 types that I'm aware of.
Yes the blue is for hfc's and the red is for cfc and hcfc's. It seems to work well. Starting in the field we always used the same refrig oil that was in system on the flare seat. This seemed to do the trick. Almost anytime I have seen someone not put oil or nylog then there is a leak. Thanks for your detail!
I’ve watched several of your videos and I just want to say thank you. They’re very helpful and informative!
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Hey buddy. @ 3:45 You can use a valve-depresser. thats what I use and there is no worries about gas coming getting spilled while accessing the system.
Great comment, those take the rush out of the process!
Can you make a video on how the refrigerant flows in a ductless multi zone ductless system? Thank
Hi there, do you have a video showing the evacuation process for multi zone units?
Good job mr 👍 I loved this felid
I'm glad
Nice video. Good explanation of how to charge a mini split system, however, I think you may have forgotten to multiple the 20.92 times 1.08 which gives you more like 22.6oz. I know its not a big difference and maybe you just figured the .08 extra per five feet wouldn't make the much of a difference. What do you think?
You are absolutely right. It was a hot one and I did my calculations on another sheet. I do however put a little over on the mini splits by shutting the tank down and weighing in the liquid that is left in the yellow service hose into the service hose. It will be very close, good catch and thank you for your very nice question. Thanks for your comment!
No problem. Thanks for replying. We've all been there on those hot days. I installed that same outdoor unit on my own house last year. It is a good unit and much more efficient than my old 10 seer York central unit. Just subbed you today and have watched a few of your videos. You do a good job explaining what you are doing. Very helpful!
Thank you very much John! I hope you enjoy the other videos!
3 years later im another one to actually follow the math lol.
Thank you for the vids and info sharing peoples. Hope all is great. How are the systems doing?
That's whats I was thinking! Thank you for the observation
Love this channel.. 👍👍
I appreciate that!
man cant wait brother very excellent video's!!!!!
Thank you!
Good work my bro!
Thank you!
Well done once more great teacher
Thanks Chick!
Thanks!
Thanks great video, especially as I am about install exactly the same make and model.
You have clarifed for me if I need to add more refrigeration as the instructions are contradictory.
Just one question, when you say the liquid line length do you just mean the 1/4" line length not the 1/2" vapor line as well?
Thanks for your your help.
Excellent video - detailed and concise. Questions. The 21 oz weighed includes refrigerant in the suction hose. So how does one get those few to several ounces into the system or do you (after video ends) add a few more ounces to account for hose amount? Prior comment on use of low-loss fitting at the suction line port was also on my mind. Thanks
If you purge your hoses of air and then zero out your scale you get the exact amount of refrigerant in the system .......There would be a small amount left in the hoses which if you added to the system would put you over the additional amount... is let out into the atmosphere under the di minimus law
Thanks zeke112964 for the clear explanation. That makes sense.
I did charge what was in the yellow service hose into the system. If it were adding refrigerant to a system during a superheat or subcooling process you would or could shut the bottle down and continue to charge what is left in the yellow service hose into the system while monitoring superheat or subcooling to make sure that you don't put too much refrigerant in. This would get rid of the refrigerant in the hoses for you. With minisplits I do usually put the yellow service hose's refrigerant into the system or I will stop short an ounce or so and add this in. Thank you Zeke112964 and Papa Joe for your Comments!
A valve depressor tool for the suction and the liquid line is a great add on to a set.
great video, i see why you can only charge by weight. if its only a single lineset then you can charge by subcooling correct?
If it is a standard compressor then yes but if it is an inverter system then you need to charge by weight. Always check the manufacturers rating plate or on the inside of the service door for directions, thanks!
You ok 👍
Very good video. Thanks.
Thank you for the Comment, I am glad you enjoyed it!
Do you have any videos showing putting a vacuum on a branch box with multiple heads
Hi how do you pull a vacumm on a mini split 3 zone that has three different line connections
if I am using only 2 zones and a total of 30ft line sets do I need to recover the rest of the factory precharge refrigerant? or not? I have the exact same unit. Thank you!
In an instant where you don't know the amount in the minisplit unit due to a flare leak, do you personally reuse the recovered refrigerant and then add additional or just use virgin refrigerant on the recharge? Thanks in advance. BTW... I FINALLY order all of your material. It only took a year! :~) -Brian
I would reuse if the system was still in a positive charge and a good amount, maybe other people can answer that too but this video is getting old
Thank you for the videos
Thanks Ron!
Thanks a lot sir
very good video, i install 1 zone mini's never a 2 plus zone... if you could invent a board that would maintain a constant run for the fan invertor just for the mini splits preventing having to reweigh in a charge, you'd be a rich man
I think that would be a great one!
Great job
Thank you!
Great video. Cheers from up in Canada
Thanks and glad you are enjoying the Channel there in Canada! How is the weather up there presently in terms of temp and humidity with people needing emergency service?
Thanks for these extremely helpful videos. AC companies in my area won't even return your call as they are all too busy and frankly they just don't care as business is booming. I've decided to tackle my mini-split install myself. I'm finding it expensive however to buy all the proper gear for the install. If I pull a vacuum down to 500 microns is it safe to say I have no leaks in the system and don't have to pressure test with nitrogen? Buying the nitrogen tank is expensive and I won't be brazing anything. I did buy the flare tools etc.. Thanks.
One more question. Once I pull the vacuum how do I reconnect the charge hose from the vacuum pump to the refrigerant tank without introducing air into the system? Thanks again..
Up here in Alberta its been a hot summer for us. As we are in celcius our summer was consistantly 24-30º c with high humidity. Our seasons are different with you guys down south as summers is AC season and we sell, service and repair like you but generally speaking if someones AC system goes down it is not considered an emergency unless of course its a business. But come fall and winter where we usually average around -15ºc and some spells of -30º+, if someones heat goes down we go aroound the clock with emergency no heats. Probably like you, I love the emergency calls...good money :)
Keep up the good videos...I really enjoy them. Cheers
Where I am located at by the shore, we have a lot of summer tourist activity and that would be considered business service calls to us. We have to go as if it's a no heat call in the winter. I am glad you are enjoying the videos! I will transition to preventative maintenance and gas line videos likely in between seasons and start making furnace and heat pump videos. Thanks and have fun!
did you applied vacuum to the line sets and purged them from all air??
Great videos. Enjoying very much. Thanks for sharing your knowledge.
I'd like to ask a questions: Apart from refrigerant charging, when do we have to take care for the compressor oils? Does the refrigerant charging containers contain the compressor oils, as well? And since I live in Europe where mini splits are very popular, what kind of care do they need regarding their (mini split's) compressor oils.
Again, thanks for the great job.
Great Question! So the outdoor units always come with oil from the start, even systems that are considered dry without refrigerant do have the oil in them already unless the manufacturer states it does not in some weird circumstance but any one that I am familiar with will have it already. The oil is miscible and will travel with the refrigerant throughout the system and through the vapor compressor. The only care that is needed in regards to oil is to make sure that you are not introducing moisture into the system via the your service hoses. You should also make sure that you have a good vacuum on the system that holds 500 microns or better before allowing the refrigerant from the outdoor unit to the lineset and wall units upon initial installation. The oil will last as long as the system does and will not need to be changed. Thanks
Have you done any videos where you charge from zero? So vacuum both sides of the service valves and add the whole amount of refrigerant. How much will go in before you have to turn on the unit
Next time i recommend planning it all out and thinking like someone that does not already know how to do this. I wrote technical manuals for over 20 years, and there are dozens of steps and assumptions made here that someone like me, trying to do what you are doing, has virtually zero chance of success.
Could you explain a little further why we dont see the full subcooling and superheat with inverter type systems?
They limit the superheat down to a ery small amount typically 0-5 degrees when on max cool. This is for the extra efficiency and also since they have an accumulator for compressor safety. I wish they would put the numbers out there when at a specif speed but they don't. Subcooling isn't read since there isn't a port. You could read it with just temp sensors though. Subcooling and superheat will change when the system is ramping up or down depending on how many head units inside are running. Thanks
Johnmiller102 go to mylinkdrive.com is a Mitsubishi web page the have videos explaining the hole process and flow of refrigerant from the simplest mini split all the way to vrvs and vrfs you will be amazed the amount of information is in this web page
4:17 it will not "take the average". First-order approximation/model: pressure is equal to lowest temperature saturated vapour pressure in the line set. Some parts of pipe may have super-heated vapour. No parts of pipe may have "sub-cooled vapour". Refrigerant migrates to the lowest temp. location and the liquid-vapour equilibrium P/T values in this location are decisive.
When you vacuum down a mitsubishi with multiple indoor units, are you connecting to a single port to vacuum the lines to all the heads at once?
I just recovered 2 similar units that were installed briefly then decommissioned because the plant they were in has airflow problems and all the air these units made was sucked up and out the through the roof, and did not solve their problems.
The wall units had already been discarded but because the refrigerant hadn't been recovered yet they were storing the condensers. I have a shopping list made up with wall units, line sets, and disconnect boxes. I am a millwright by trade but mostly work on air compressors. I plan on installing them for my home myself, with the help of an electrician for setting up my disconnect boxes and HVAC tech to purge, vacuum test, and charge my system.
Is there anything in particular about these units that I should know? Someone online mentioned Mitsubishis can be tricky to wire but based on the manual it doesn't look any different than your complete install video I watched the other day, other than having to wire 3 separate units vs the one in your video.
PS, you aren't related to Seth's Bike Hacks are you? Same NJ accent and talent for video production
can I ask what is the correct operating pressure ( blue ) - low line - for this exact type of Mitsubishi ? i have exactly the same 4 zone system and want to check if it is overcharged ?
Are find solutions? Please share with us :)
Hi I’ve recently installed a Fujitsu AOU36RLXB
It comes precharged with 4lbs 10oz. Of 410a from the factory, which is rated for 66ft according to the manual. It states that if the line length is below 66’ no additional charge needs to be added. I only used about 20’ of line between the outdoor unit and the indoor unit. In this situation do I leave the precharge from the manufacturer as is? Or do I have to recover some refrigerant. Thank you!
Do I vaccum the zones on at a time? If so would I get any air sucked in when I remove the blue hose to do the vac the next zone or is there a valve to use to vac all the zone lines at the same time? Thanks for your great vid👍
They all get done at the same time and there is no way to separate them anyway, thanks
Mitsubishi also require that the wire be stranded not solid core wiring
about to install this same unit. why does the install manual say that it only comes charged with 25ft worth yet on the unit itself says to add if more than 98 ft?
Love the video, hate the intro!!
Those line sets looked CRAY CRAY ZIP TIED lol good video tho
They all had to make it through a 4" pvc through to the crawlspace!
Nice work man .. I am new in this matter, but I have understood that mini splits are like piston expansion.. my question is related the way it was charged the unit.. Can I charge by superheat instead of by weighting the refrigerant? Thanks in advance
If the mini-split is an inverter style than you must charge by weight only because it ramps up or down and there is not a steady superheat or subcooling. Thanks for the question!
There is a trick you can use to get them by for a short time if it's really busy or a holiday weekend. You set the indoor units to cool and push the Emergency Operation buttons all of the units. That puts the whole system into high cool regardless of the indoor and outdoor temps. Mitsubishi says the saturation TEMPERATURE on the vapor side should be between 45-50deg F. Add refrigerant until you're in that range and it will cool quite well until you have a chance to go back and find the leak and repair it, then recover and properly weigh in the charge. You'll find that the amount you took out will be pretty close to the amount that you have to put back in
so if the factory charge is good for 98 feet and say you only use 50 feet they dont require you to recover any? so that tells me that these systems are more tolerant of being over charged. Or am I missing something? Is this because mini splits have an accumulator? just trying to understand, im new to this but trying to learn.
I have a mini split with 2 indoor units. At the outdoor compressor unit I see there are four lines and 2 lines with service valves. Which service valve should I connect to? Or doesn’t it matter. Thanks!
If one were to install a multi zone unit as shown in this video, and added an additional air handler to the multi zone compressor down the road, would connecting the new air handler line sets cause any loss of refrigerant? And how would one test the newly installed line sets for leaks, again without losing refrigerant? Please forgive if my question is absurd, as I am not an HVAC pro.
Yes it would as there is only a vapor service port for you to pull a vacuum from which is connected to all the rest of the indoor wall units. You would have to pump down the system and/recover the refrigerant, pressure test the linesets, vacuum pump the system along with the new lines and indoor unit and weigh in the refrigerant accordingly, thanks
why divided by 5? where did you get the #5
That unit said to add a certain amount of ounces for every 5' of lineset added past the maximum length of lineset for refrigerant that came with the unit, thanks
Very good video, will you be more videos on mini-split units. Just started getting into a/c and installing Fujitsu Mini-Splits. In there info on unit say it needs a minimum of 16' of lineset, wondering how it shows on gauges if run is less than 16', and if it will affect unit. Thanks
You would need to recover the refrigerant if it is less than that because the accumulator may not have enough room to stop the extra refrigerant from making it into the compressor as a liquid during some of the run times. Thanks for letting me know what you would like to see!
Do you still use the TIF 9010A Slimline Refrigerant Scale, 110 Pound Capacity?
yes I do and it works well- amzn.to/2b9oXYl
Sitting on a roof. Staring at a MXZ-C030NA Mitsubishi 3 zone. Really used to doing refrigeration Subcooling. What the general recommended number for these inverters? I know it’s really too high at 43.2 460 psi high side and temp 85 degrees which gives a condenser Tsat 128. Temp outside is 74 & raining.
Ive pumped down my mxz3 and want to weigh in the liquid. Which line do i use
I followed your TH-cam channel very informative. I believed all this Inverter units are pre-charged by the manufacturer. But I didnt get how much LINE set in ft.?? for the specific pre-charged, then you add if you get over the line set I get that. Am I missing something in this videos.
Each unit will state on the rating plate up to how much lineset can be used for the amount of refrigerant in the unit. These lineset lengths will be different on different model numbers or sizes, thanks
Can you check saturated on evaporator with inverter?
I installed a multi head unit , one of the indoor wall units freezes up. Do you have any idea as to why
My unit has a max capacity of 128 oz so 8 lbs how do I go about knowing how much lbs it already has inside the unit? Should I just add 2 lbs to be on the safe side
Hi
Can you please help with mxz-8c48na
My question is should I change outdoor unit thru service port low side or charging port low side?
Thank you in advance
Can these be charged with 410 when it’s cold outside?
Thanks for making this video! I'm getting ready to install a Pioneer split mini, and it calls for 0.16 oz per additional foot. It comes charged for 16', and my run is 50', so I believe I need to add 5.44 oz. Do I have to charge with the tank upside down? I may just use the additional charge to break the vacuum. That seems like the easiest way to do it. I wonder if it will pull in 5.44 oz. Do I need to do it a little at a time if the system isn't running?
As long as you are EPA 608 certified, If it is R410a then it has to come out of the bottle as a liquid (upside down in disposable bottle). If you are breaking the vacuum then it gets weighed in as a liquid. Make sure to use a hose with a valve on the end and purge the air out to that point and then connect to the port, then zero the scale out, thanks
Thanks so much. So a liquid charge adapter is not necessary in that case correct?
No you wouldn't use one with breaking the vacuum with refrigerant, thanks
what is the amount for a single zone unit that has 16 feet or 32 feet total
Do those multi indoor systems have the expansion valves at the evaporators and uses true “liquid” lines? I know the singles have the expansion valve in the condenser and your line set is an extension of the evaporator and that’s why both lines are insulated.
Yes especially the vrf units like these have the txv outside since it is electronic. You are correct with the rest of what you mentioned, thanks
Hi I’ve just installed a Fujitsu multizone 4 head system and used 3 line sets of 50’ and took out about 10’. Do i Measure each line set as a 50’or 100’ since you have liquid line and suction line so is it 150 ’total or 300’ total. Maximum line to be used it says 163feet. Thanks
if you lose some refrigerant how much to add?
I have an LG 3 zone mini slipt just checked the gas line on my low line and its reading 290 while all 3 zone are running i have 100 ft of line set system has 3.97 lbs of r410 at 73.8 ft i need to add 8 oz to top off why is my low pressure hose st 290 i though I needed to add more refrigerant my handler unit temperature is 57 degrees should it be lower thanks
Did you do an installation video for this? Thanks
Sorry, just this part, thanks!
thank you now i understand. but for example the one i have is daikin mini split inverter 12k btu and i need to add .16907 oz for every 5 additional feet. so using your same calculations. 20.92 * .16907 = 3.53 oz of refrigerants. when comparing mine to yours, isn't 3.53 oz a bit low?
You would look at your daikin and see how much they want you to add for every additional 5' or 1' and add up all your lineset lengths to add more than what the unit came with. If it was a leak then you would recover, fix leak, pressure test, vacuum, weigh in initial amount plus any additional feet, thanks
hi, so if you had check for proper refrigerant level how would you do it if we're not measuring superheat or sub cooling? i mean just looking at the gauge how'd i know if i have the correct charge? thank you.
You may not but just from experience on systems that know had the correct charge, the superheat was 0 to 5 degrees on the vrf minisplit systems I have been installing and the accumulator protects the compressor during low superheat, thanks
Hi, is it necessary to purge the hoses before charging the refrigerant?
Yes purging assures that you don't have noncondensables or water vapor in the line which will contaminate your new charge. Thanks
Is there a way to vacuum without gauges.I remove Schafer core but I can’t attach my micron gauge due to the port been so close to unit any suggestions?
Can u add the link to the book
www.acservicetech.com/the-book for the paperback and e-book and also the www.amazon.com/shop/acservicetech for the paperback thanks!
I just worked on one of these for the first time and have a question. I noticed that tag on that small line to the left said it is where you should charge it. Why did you hook up to to the big line to charge yours?
This line still goes into the accumulator so it is still safe for the compressor, thats all, thanks Robert!
Thanks for these extremely helpful videos. AC companies in my area won't even return your call as they are all too busy and frankly they just don't care as business is booming. I've decided to tackle my mini-split install myself. I'm finding it expensive however to buy all the proper gear for the install. If I pull a vacuum down to 500 microns is it safe to say I have no leaks in the system and don't have to pressure test with nitrogen? Also once I pull the vacuum how do I reconnect the charge hose from the vacuum pump to the refrigerant tank without introducing air into the system?
Ok just saw your other video on weighing in refrigerant. Noticed you have a shutoff valve at the end of the hose to prevent air being introduced into the charge line. Thanks again...
Yes if you didn't have the valve then you could just vent the air out of the top at the gauge manifold until it was just refrigerant in the hose. When I am switching from vacuum to charging I close the gauge set also before disconnecting the micron gauge.
thanks .. do i have to pressure test with nitrogen if I'm able to pull a vacuum down to 500 microns?
Great Question! If the lines were bigger in diameter and you had a 3cfm pump then I would say it is likely that you don't have a leak but I always pressure test. It really also depends on how big your vac pump is and where you place the micron gauge. You can check out this video. th-cam.com/video/nBCWYgCcnpE/w-d-xo.html
Thanks again for sharing your knowledge. You're helping thousands of people and your videos are some of the best instructional videos I've come across. I'll be placing my order with amazon using your embedded link. You may want to publicise the link in all your videos as I stumbled across it. I'm sure people will be more than happy to support you any way they can.
When the ductless mini split needs to be charged we cant use the low side to charge it? we have to go through accumulator? Also how do you pump down a fujitsu or mitsubishi mini split unit.
If it is running, the low side will flow through into the accumulator, we are just weighing it in. You would still watch the vapor gauge, shut the liquid service valve, and then shut the vapor service valve when it gets low enough. Thanks
Can you pump down multisplit if there’s a lot of additional charge in it ?
It depends just how much extra you are talking about as well as the size of the accumulator in the outdoor unit, thanks!
I have to add a couple ounces of R410A to a Mitsubishi H2I 6,000 btu unit, 35 ft line set (10 ft over pre charge limit). How do I get the air out of the manifold and hoses, I assume that's what you mean when you say "get the air out". Do I pull a vacuum on the manifold and hoses and then attach the hose to the service port and refrigerant? I've already released the pre-charge into the system.
You could use the systems pressure to purge the air out. Look up "acservicetech connect, disconnect procedure" thanks
Thank you
How would you weigh in only through the low port if there is no pre-charge?
Well if you did a repair, say on the compressor or solenoid valves you could go ahead and braze a 1/8" access valve onto the liquid line inside under the outdoor unit cover. The unit also has an accumulator and the last time I talked to a Mitsubishi tech they said it was normal to have 0-5 degrees of superheat while running on full emergency cool on all indoor units. My question was isn't that going to damage the compressor if you don't have superheat? The tech on the phone said that they are safe even when running at 0 superheat because of their accumulator. We know accumulators have their own metering device so at least it is at saturated state but mainly vapor. To be extra safe you could braze an access fitting right in the side of the liquid line under the cover. Remember that they design these specifically so that people don't try to charge them in subcooling. They also design them to have flares so that the torch doesn't touch the lines. The problem is not the torch but that many are not running the nitrogen through and the manufacturers don't want the blame of all that oxidation clogging things up. Most of the refrigerant from a system that says you can have up to 125' of lineset when you only have 30' is just sitting in that accumulator so technically it would have to go there before going to the compressor. To be sure, check with the manufacturer themselves at tech support to be sure of their recommended procedure. Thanks
Thanks for the quick response. I have a daikin rxs24dvju that is over 9 years old and hasn't been running for about 2 years now. I believe all the gas has just leaked out of the flare probably because it wasn't bolted down and people would bump and sit on the outside unit. So I tightened it up and pulled a vacuum on the whole system and it seems to be holding. However with no gas and only a low side service port I'm not sure how to weigh in. I don't really want to put to much money into it as it might not be worth it and im not sure i'm experienced enough to braze a 1/8" access valve into the liquid line. Would it be completely wrong to sip in r410a through the low port while the unit is off and under vacuum? Or should I turn the unit on and try to sip almost 4lbs of r410a in through the low port? I imagine the high and low valves remain completely open while charging?
You would still need to get about 2-3lbs at the very minimum in before starting it so the evaps don't all freeze and you have some refrigerant to work with. If that is the case not much difference between that and the 4lbs it needs. You could call tech support for Daikin. It is certainly different than a standard condensor because of the accumulator. See what Daikin says. It won't hurt. It sounds like you know what you are talking about and they should give you the info you need. Thanks
Would such a "vacuum/charge valve" from Yellow Jacket help when connected to the high side? Would it provide an access port to mini split's high side without soldering? (I mean the left valve which is depicted in the following link)
yellowjacket.com/product/vacuum-charge-valve/
There is no need to have a valve on the high side with a variable refrigerant flow unit. Mitsubishi just wants us to weigh the charge in. The tech support stated that a superheat of 0-5 degrees would work when on full emerg cooling on all units and I have checked some of my installations and they range from 2-4 degrees of superheat when it is 70 degrees or higher out. Thanks
When they mention to add refrigerant per every 5 ft of line set, what if you only use 3 indoor heads on a 4 zone system? Is there anything change when only using 3 heads instead of 4 heads? Thank you.
It is cumulative lineset not just to one head unit. They get added together. Also make sure that your system can handle one less communication wise and that you are using the capacity of the system properly by verifying in the manufacturer's literature, thanks!
I am running a 4 zone unit. Two of the indoor units are cold and one is not real cold.. is that a bad indoor unit possibly
I checked the psi and it around 130ish
How do we pressure test a multi zone mini split heat pump system with only one set of service valves? Thanks!
The tubes are all connected usually so you just need one port, thanks!
My unit service port is separate. Doesn't have a main port to add refrigerant
Why not just weight the refrigerant before starting the system??
Certainly you can do that and I often do that more than adding while the system is running, thanks Kevin!
How do i get to run in start up am060mx
Cant remember with button to hit
I have a multi-zone mini split. But one of the unit begin to frost when the unit is off while another room is running. Is the that is off low on charge?
communication wire are probably not hooked to the right unit
Actually Mitsubishi say you can charge to 7° superheat.
They told me 4
hi, how come we don't look at the high side pressure? thanks.
They don't want you to look for subcooling and try to use that as the charging method so they just want to see superheat for diagnosis, thanks!
I have a 3 zone Mitsub. when one inside unit is running i can hear the refrigerant running through one of the other units , is that normal ?
Cross wire
sir I have sharp eco inverter 15000 BTU can u explain sharp is good company bcz I already Install my room.
Companies install certain brands because they feel that they can get service parts for them faster. There are a lot of good units manufactured by different companies. Thanks for your Comment!
How much liquid refrigerant can the accumulator actually hold? Is there ever a chance that it can "overflow"?
Yes you can overfill. That's our problem as we do not know how much refrigerant is in it if we suspect a leak and thats why we have to recover and start over if there was a decent leak, thanks
Thanks for the info. Another question. Today I replaced an evaporator on a mini split LG. I got a good vacuum and charged the system by weight based on the specs. When I started it up, I was getting some frost on the valve of the "liquid" line (quarter inch line). Is it normal to have a little frost there? It seems that maybe its low on refrigerant, but I weighed it in...not sure what to do. I do not have excessive line set. Only have about 10' total.
Usually there is not. So check to see if you have the system on max cooling, see if you have 1-5 degrees of superheat. If you have a higher superheat then it may still be low. Also check to make sure that you have 19-22 degree temp decrease across the indoor evap coil. If you have less then maybe you are low. Is it possible that the scale was somehow not measuring correctly? thanks
The scale is only about a month old, but I guess anything is possible. I will double check those things you mentioned. Thanks a lot for the feedback!
hi i was wondering if i could ask you few questions about charging a LG mini split Multi zone unit?
Go for it!
Can u top off a mini split without pump down and adding all the refrigerant ??
installed a LG mini system... pressure running 114/140 inverted compressor.. Lines set is 48 ft have not added any 410 yet... any thoughts?
What does the unit say to add per every 5' of extra liquid lineset on the rating plate or are you within the proper amount of length worth of lineset?
I have same problem when do I add refrigerant before first start up ???
How you’re you know if this things are low on charge or leaking?....
High superheat during full cooling capacity. low delta T thanks
@@acservicetechchannel
Sorry I'm a bit confused. In the video you said you couldn't charge by superheat/subcool, could you explain further?
So u can do superheat when unit is in force cooling ???
I had to cut my line set prob about 12 or 14 inches from the factory length am I ganna have to evacuate some refridgent or do you think I'll be ok if that's the case I'll prob just get another factory size lineset so I dont have to mess with evacuation some ...any info will be highly appreciated
It should say on the rating plate of the outdoor unit from what length the what length is ok without having to add or recover any refrigerant, thanks
@@acservicetechchannel thanks for the reply its actually good to go but I appreciate the reply I really do
@@acservicetechchannel I seen that on the outdoor unit it's ok the length any longer tho and I would've had to
@@acservicetechchannel I meant any shorter
Ok thanks
I need to charge back in the factory charge after a line leaked the original factory charge out, is there any way I can add it as liquid into the service valve which would be the high side while the system is in heat pump mode? and then finalize the charge using a quick charge gas adapter via low side in cooling mode while running? Or is the only way to weigh in 8 pounds and 13 ounces to the low side while the unit is running in cool mode? @acservicetechllc
@acservicetech
Loose, if the system is empty of refrigerant, pressure test the system with nitrogen under the max design pressure of the unit, release the nitrogen, vacuum the unit below 500 microns, perform the standing vacuum test to see if you are holding a vacuum. if it stays below 500 microns, weigh the correct amount of liquid refrigerant as stated on the rating plate and as needed by the cumulative length of the line set into the liquid line if there is one inside the unit, otherwise weigh it into the low side if that is the only port. the system is off this whole time. Give the refrigerant some time to saturate and circulate while the system is off, then after 20 minutes, go ahead and turn the system on. Make sure you are EPA 608 certified before buying or handling refrigerants, thanks Loose!
Just came across a mini split at a job we were at and I noticed the liquid line is very cold. Condenser is blowing warm air and there is condensation coming out of line. Is this normal operation with these mini splits? Thanks
Yes the txv is in the outdoor unit so the liquid line needs to be insulated as well, thanks!
acservicetech We were just there to silicon where the the line set came through and my lead mentioned that the crew that originally installed it had lost a lot of refrigerant from the flare nut when they were tighten it down. He said they replaced refrigerant but when I felt the liquid line I thought that maybe it was low on charge so that's why it felt so cold. I haven't really done a mini split yet so I don't know a whole lot about them. Thanks for the reply.
Why does he discount 47 fees at 250 feet, does anyone know the answer please?
???
Man these things seem problematic
Glad im not and dont install ductless, City Multi, and whatever else they can come up with. IMO- Absolutely junk.
Why are they junk? Are you just saying that because you don't understand it?