Minisplit torque settings.

[Kogashuko]

So, I have done two normal heat pumps but this is my first with flared connections. I have all the 410 tools and the flares are straightforward. However, I dont have a minisplit torque wrench but a normal torque wrench. I am using crows feet and the error for additional length (also tried at 90 deg which is not supposed to increase FTlbs even though it is a rotational rating and doesnt make sense that 90deg would change it) is well within the target torque range for the fittings. However, when I torqued down the 1/2inch copper it straight up torqued the flare off and never reached the click setting on the wrench. I then reflared the connecting and connected it. This time I torqued it and still didnt get a click. I stopped when I felt the connection getting a lot harder to tighten. I can pressure test at 350psi easy and if I get a leak just retighten. I use Co2 instead of nitrogen since I dont do this enough to justify buying the nitrogen tank, reg, and other parts. Co2 is cheap and I can refill the tank for $4 if this doesnt go well.

Anyone else experience the mfg torque ratings like this?
1/4 copper = 17.6-24.5 NM
3/8 copper = 33.3-41.2 NM

 

[rlitman]

Are you using the flare nut that came with the line-set, or the nut that came with the mini-split? Line sets come with a thin wall forged nut that is made for the lower pressures of R-22. R-410a requires some more torque, so the mini-split will come with a thick walled billet machined flare nut. Maybe that's your issue.

 

[zmaxmotorsports]

On the ones Ive worked that were leaking I just snugged them up within reason with a wrench.
Anytime I do a flare fitting install I put a little rector seal on back side of flare(nut side) before cranking it down to make it easier to get them tight.

 

[Kogashuko]

I am using the flare that came with the split. I cut both of the flares that came with the lineset, removed the crappy nut, and installed the LG ones. I think my issue with the first one was that the flare I made, first one of course, was jacked up. I had no problem reaching the torque settings on the outdoor unit but the problem was when I hooked to the indoor unit. I think I got it straight but I didnt realize the port was bigger on the ductless outdoor units so I couldnt pressure test yesterday. I had a hose from an older manifold but something wasnt right with it and it wouldnt screw all the way on and when I hooked up the vacuum pump to see if I could pull to 500 microns it simply wouldnt engage the valve and it leaked around the fitting. The Sman360 only registered a neg psig and didnt go into micron mode.

This brings me to my next surprise, the lack of a service port on the high side. I did the math and with around 12-13 feet of lineset I will only be 2 ounces different than if I had a 25 foot line set. I dont see that being a big deal since the unit holds a couple of pounds but I would still have like to check it. The LG youtube video says that I need to make charge adjustment if less than 25 feet. However, I found a more recent engineering manual for my unit and it says I only should have to add refrigerant over 49 feet of line set. It does not give the break down of weight per inch of hose any longer. It also doesnt give you the total weigth of refrigerant that is in there so I dont want to recover anything. It does explain how to check if the thing is over or under charged which is what I will do. The more important thing in the engineering manual is that it explains the LG software. Apparently, you can get a cable and software that connects to the unit. The unit itself has every sensor known to man. In fact I think it has a sensor to see into the future. Anyway, that software would be really helpful in troubleshooting and charging. No more hooking up the manifold and loosing refrigerant slowly over time. No more guessing on charge weight. No more guessing if the inverter is running at a constant speed. I will be buying the software since I intend to get more of these. I might even sell my Sman360 when I replace our rheem units.

 

[bazar01]

The service port on the minisplit outdoor unit requires a 5/16" SAE female to 1/4" SAE male adapter to pull a vacuum, to charge or read the pressure of the system.
You have to remember that in heating mode, the charging port will have the hot gas discharge high pressure from the compressor. So do not charge in heating mode.
And you can only charge R410 in liquid phase.

 

[Charles (in GA)]

If the adapter/crowfoot is typical, not too long, turning it 90° to the torque wrench handle will result in the center of the crowfoot open end being equal distance from the handle as a socket on the square drive would be, thus no change in torque. See the attached illustration on how to calculate a different torque when the adapter is on the torque wrench any way but 90°.

 

[fastjohnny]

These values really aren't that high. If you are torquing off the lines, I'm betting your torque wrench needs recalibration. BTW, a click type torque wrench should be stored with torque set at zero. Not doing this will cause calibration issues.

 

[Kogashuko]

Yeh I think I got it straight. I had no problem with the torque on the condenser unit. I think the flare was just messed up and wasnt making a full connection on the little cone shaped brass thing which caused the flare nut to just crush it.

I ordered the port adapter from amazon Saturday night but even with prime will not see it until tomorrow. Gives me time to do the electrical which I could have done saturday too but I hate the crawlspace. Funny thing is I can use a 15amp breaker and 14/2 romex on the thing which trips me out.

Shouldnt need any charging but if I do it I will definitely get the LG software to lock the compressor speed in on cooling mode. Looks very very simple with the software. I wish my rheem units had that.

 

[bazar01]

Yeh I think I got it straight. I had no problem with the torque on the condenser unit. I think the flare was just messed up and wasnt making a full connection on the little cone shaped brass thing which caused the flare nut to just crush it.

The flare end on mini split line sets are deeper to produce stronger joints because R410A refrigerant has a higher operating pressure than R22. Though the flare angle are the same as conventional flare fitting, the mini split flare has a higher collar flare for better sealing.

I hardly saw my 1-ton unit draw more than 3 amps to maintain a room temp of 68F.
No need for electric strips. Impressive.

 

[Kogashuko]

Yep, picked up the yellow jacket blue handled flaring tool with height stop. My only complaint is that it doesnt have a ratchet stop for it. However, after a couple of flares I got the hang of the process.

I put the vacuum pump on it yesterday and got a vacuum down in the 200 microns which is better than the 500 needed. I then filled the lineset with about 300psi of Co2 and tested for leaks with bubbles. Needless to say I did not find any. I left the Co2 in the line since I havnt run the electrical drop yet to the HVAC disconnect box on the outside of the house yet. I will probably do that over the next couple of days if it dries out a bit so I dont track mud under the crawl when I go under there. I will test to make sure the pressure is still in there. I assume that at 300lbs I would know pretty quick but then again 410a can be a bit higher. I have a leak detector for when I finally release the refrigerant.

I saw today that LG had a booth and a bunch of new products at some HVAC expo. The big take away I saw from that was the USB wireless diagnostic tool. It looks like it essentially does what the cable does to the outside unit and gives detailed info on pressures and stuff. Looks like a good idea because you dont have to hook gauges to your system every spring and waste refrigerant. It also looks like their dry contact adapter will let you install any thermostat to their zoned and multi-v products.

 

[Kogashuko]

So doing the leak test I found nothing with bubbles but the psig dropped about 10 in 24 hours. I tried again this morning and the loss was about 7. I need to determine at this point if the loss is from attaching and removing the manifolds (since I purge all the co2 each time,) from temp change with liquid in the line, or from a very small leak. I am leaning towards a combination between the first two since it has gotten progressively colder since Monday night and the lineset is so small and thin I wouldn't think it and the indoor coil could hold that much volume. With Co2 starting as a liquid if any got into the system past the reg it would stay in the lowest part of the tubes near the charge port and be the first thing to go when connecting and disconnecting. Just to be safe I might load it back up to 300 tonight and see how much I lose by just screwing in the manifolds and disconnecting them each time.

 

[bazar01]

Of course drop in gas pressure could be due to drop in temperature. pv=nRt.

To be sure, if you have an electronic leak detector, I would put a little R410A refrigerant first and pressurize with nitrogen or CO2 to 300 psi (design high side is 500 psi). Then test for leaks at the fittings. Keep the service valves closed while doing this test.
If leak test is good, pull a vacuum again and let it sit for 6 hours and check for pressure rise.

I did all these and my fittings still developed a slight leak on the inside unit.
I was forced to put a dye to trace the leak.

 

[Kogashuko]

I get the feeling that after all of this I will have done a better job testing the system than if I hired an HVAC company to do the install. Worst case scenario I release the refrigerant, use the leak detector, and then look for oil on the fittings every few days. Not ideal but with enough refrigerant in there for 49ft of lineset I think I will be fine if I find a very small leak later. I very well could put 500psi in but at that point I run the risk of pulling in massive amounts of liquid in that could potentially spike to 1000 psi if the temp rises. Best to keep co2 under 500 psi to keep it a gas. I dont have access to my own 410 to mix for trace right now.

I can just imagine if a local installer came out he would have put in 300 psi, used bubbles, did the vacuum, and released the refrigerant all in an hour or two hour time frame.

 

[bazar01]

I dont have access to my own 410 to mix for trace right now.

I can just imagine if a local installer came out he would have put in 300 psi, used bubbles, did the vacuum, and released the refrigerant all in an hour or two hour time frame.

You don't have to have your own 410 to mix. You can momentatry open the service valve, wait until pressure goes up to about 10 psi, close it back up then pressurize with nitrogen or CO2 to 300 psi.

I know what you mean, local installers don't spend that much time like we do to do the install and we still F up. The good ones are usually in and out in less than a day and very proficient.

 

[Kogashuko]

You don't have to have your own 410 to mix. You can momentatry open the service valve, wait until pressure goes up to about 10 psi, close it back up then pressurize with nitrogen or CO2 to 300 psi.

I know what you mean, local installers don't spend that much time like we do to do the install and we still F up. The good ones are usually in and out in less than a day and very proficient.

Well installers F up plenty. Hints one of the reasons I decided to do mine. I cant see paying someone over a grand in labor to do what I just did and leave not having a clue rather I have a leak or not.

 

[zmaxmotorsports]

Well installers F up plenty. Hints one of the reasons I decided to do mine. I cant see paying someone over a grand in labor to do what I just did and leave not having a clue rather I have a leak or not.

that's why you pump it full of nitrogen and listen for leaks,not all hvac guys are hacks.

 

[bazar01]

Well installers F up plenty. Hints one of the reasons I decided to do mine. I cant see paying someone over a grand in labor to do what I just did and leave not having a clue rather I have a leak or not.

Not always true. The good ones do a very good job and have the right tools and knowledge too and will back up their work.
Some of us maybe fortunate enough to have a good knowledge, understanding and common sense to do hvac work, we still cannot do eveything due to priorities and time constraints. It is still still a good idea to work with a local contractor you can trust.

 

[Kogashuko]

Not always true. The good ones do a very good job and have the right tools and knowledge too and will back up their work.
Some of us maybe fortunate enough to have a good knowledge, understanding and common sense to do hvac work, we still cannot do eveything due to priorities and time constraints. It is still still a good idea to work with a local contractor you can trust.

Your absolutely right. I know of a couple I would trust. Several being close friends that don't live near here. One local contractor that would be good. However, I don't know of any that would pump the system full of nitrogen, test for leaks, and then come back the next day and then the day after to see what the pressure level is. In this case if I still have a leak, don't think so, then I found a leak that only I would have found. I did everything they would have done minus using Co2 instead of nitrogen (you will find several forums saying there is no difference other than cost.) If I find a leak now it is due to diligence that a contractor would not have. He would have simply pressurized to 300 (I am being nice probably 100,) done a leak test, vacuum tested, and been done. Just like I could have done but could. Either way by spending a few more days with the pressure testing I will be night and day better than any contractor.

 

[zmaxmotorsports]

Your absolutely right. I know of a couple I would trust. Several being close friends that don't live near here. One local contractor that would be good. However, I don't know of any that would pump the system full of nitrogen, test for leaks, and then come back the next day and then the day after to see what the pressure level is. In this case if I still have a leak, don't think so, then I found a leak that only I would have found. I did everything they would have done minus using Co2 instead of nitrogen (you will find several forums saying there is no difference other than cost.) If I find a leak now it is due to diligence that a contractor would not have. He would have simply pressurized to 300 (I am being nice probably 100,) done a leak test, vacuum tested, and been done. Just like I could have done but could. Either way by spending a few more days with the pressure testing I will be night and day better than any contractor.

Hell I could leave nitrogen in your system for a year to leak test it if makes you feel better,Most people don't want to be without their new system any longer than they have to.
Leaving the nitrogen in the system for 4 days is not going to make it work any better than it will leaving it in for a couple of hrs.and it sure as hell will not make you night and day better than any contractor.
I could teach my 6 year old grandson to flare copper and dump nitrogen into a system to pressure test it,its not rocket science by any means.
If you want to show me how good you are show me how you silver solder some med gas lines.

 

[bazar01]

Either way by spending a few more days with the pressure testing I will be night and day better than any contractor.

In my opionion, leak test for a few days is a waste of time.
Leaving it a few days does not improve the effectiveness of leak test just by monitoring nitrogen pressure thru gauge manifold pressure readings. It is a constant volume system that is subjected to temperature variance, your pressure readings will drop or rise with temp. And hoses are not made of a gas barrier material.
Best way is to use an electronic sniffer with the nitrogen charge and a trace of refrigerant and you will be done in less than an hour.
I did not have one so I just did a vacuum test and still F up.

Remember that these units have threaded connections and they are prone to micro leaks which may only show two or three seasons after install.

 

[Kogashuko]

Hell I could leave nitrogen in your system for a year to leak test it if makes you feel better,Most people don't want to be without their new system any longer than they have to.
Leaving the nitrogen in the system for 4 days is not going to make it work any better than it will leaving it in for a couple of hrs.and it sure as hell will not make you night and day better than any contractor.
I could teach my 6 year old grandson to flare copper and dump nitrogen into a system to pressure test it,its not rocket science by any means.
If you want to show me how good you are show me how you silver solder some med gas lines.

I love how some HVAC guys become \%÷×$ when you disagree with them on something.

The point of leaving it is to determine if I have a slow leak and really doesn't matter because I was waiting until today to run the electrical in case I have to kill the panel I will have sunlight instead of a maglight to connected the wires by. Shouldn't take five minutes so I am probably going to do it hot. I really dont trust the electronic leak detector so I want all my ducks in a row up until then.

On to the silver soldering. Yes it is effective but for my purposes these flares are a nice tool for the toolbox. Nothing like lugging a tourch into the attic filled with cardboard boxes to solder in a cramped spot. Doing more of these splits and connecting them in places like a bedroom with the connection near drywall makes flares easier than worrying about tourching the wall making the connection.

Bottom line. I would have paid someone at least 30k in hvac work in this house that I might have spent 3k on. Yes you would have been quicker but I would still have been paying.

Finally, Zmax I dont have to prove anything to you. If you dont like something I said don't be a ÷/*] don't say anything and feel free to find your way out of my thread.

Also, if I misread what I thought was anger and you are actually joking (hard to tell with only text sometimes,) I apologize for the above and the way it probably came off. I came here to have an intelligent and adult conversation. Not to beat on my chest and talk about how "good we are."

 

[zmaxmotorsports]

I love how some HVAC guys become \%÷×$ when you disagree with them on something.

The point of leaving it is to determine if I have a slow leak and really doesn't matter because I was waiting until today to run the electrical in case I have to kill the panel I will have sunlight instead of a maglight to connected the wires by. Shouldn't take five minutes so I am probably going to do it hot. I really dont trust the electronic leak detector so I want all my ducks in a row up until then.

On to the silver soldering. Yes it is effective but for my purposes these flares are a nice tool for the toolbox. Nothing like lugging a tourch into the attic filled with cardboard boxes to solder in a cramped spot. Doing more of these splits and connecting them in places like a bedroom with the connection near drywall makes flares easier than worrying about tourching the wall making the connection.

Bottom line. I would have paid someone at least 30k in hvac work in this house that I might have spent 3k on. Yes you would have been quicker but I would still have been paying.

Finally, Zmax I dont have to prove anything to you. If you dont like something I said don't be a ÷/*] don't say anything and feel free to find your way out of my thread.

Also, if I misread what I thought was anger and you are actually joking (hard to tell with only text sometimes,) I apologize for the above and the way it probably came off. I came here to have an intelligent and adult conversation. Not to beat on my chest and talk about how "good we are."

I know how good me and many of the guys are on here,we come on here and give free advice to people all the time on how to fix their problems.
Coming on here and saying that you do a better job of installing than any contractor because you let the nitrogen stay in the system 16 times longer than it needs to is nothing but a kick in the nuts to the guys who do it every day.
Would you leave the gas lines on your house capped/pressurized for 4 days before hooking up a replacement furnace in your house?
Natural gas is a whole lot more dangerous than a Freon leak,So I would think youd want to treat it atleast as seriously .
Anyway life is too short to stress over little stuff.

 

[Kogashuko]

Coming on here and saying that you do a better job of installing than any contractor because you let the nitrogen stay in the system 16 times longer than it needs to is nothing but a kick in the nuts to the guys who do it every day.

Hey we are good. I can respect you speaking your mind in that way.

Can you honestly say that everyone that puts stuff in for a living that is worried about getting to the next job does a good of job checking things as they should? Some do and I know a few guys personally that I trust. Problem is how do you know when they do something or when they don't. I don't mean it as a kick in the nuts to all of them but there are a bunch of guys out there in your trade, and many others for that matter, who take the path of least resistance. Unfortunately, I am a little pessimistic and tend to think the worst of people sometimes. Not meant anything personal to any of you at all. I just think when someone does things theirself for theirself they tend to do them better!

I have had several bad experiences. I remember my mother called an HVAC guy to replace her heat pump about 5 years back at her place and charged her 5 grand. He refused to answer her phone calls when she had problems. So eventually she called the manufacturer and they checked her serial numbers on the units. They immediately invalidated the warranty because he miss matched coils. So she paid another 3 grand to have another installed and he installed a 1.5 ton 13seer goodman with no heat strips (didn't even explain to her that they were needed in va climate.) A simple swap in and swap out with no duct work, in a walk in basement, with about 10 feet of line set running out a hole that was already there. When my siding crew hit both of my rheem units and cracked the refrigerant lines they called out a random local installer to repair them. They tried to tell the them that they needed to move the outdoor units from 15 inches away from the house to 24 inches and that it would be very expensive but had to be done. When I showed them the service manual, included with the unit, calling for 10inches , they said that it was a requirement for the permit. He shut up after I asked him when was the last time he pulled a permit to replace a heat pump. It is this type of stuff that gives a black eye to all the good contractors out there.

As for the gas question, I have never lived anywhere with natural gas. I have had propane appliances. I can say working with it and the thought of a leak makes me uneasy. Me personally, if I were to run natural gas or any other gas lines into my house I would probably be tempted to pump them up twice their operating pressure and leave them a week. They are relatively low pressure when compared to 410a but still I would sleep better at night. That being said I asked a friend who is a fire fighter why we don't have more gas issues and he was talking about how rare it is to get the right gas / oxygen mix to cause an explosion. This makes sense but I do know of one house nearby that exploded after filling up with propane. I believe it was an insurance scam but I can tell you that the explosion was heard several counties over. I felt it in my car and I think I was at least 20 miles away. That very thing made me want to never use gas appliances.

No personal attacks or nuts kicked intended.

 

[Kogashuko]

Finished everything tonight. Found the pressure loss was the same each time I hooked up the manifolds. I hooked up the vacuum pump while connecting the last few wires and left it on for around an hour I think. I didn't think it would take but 30min but my toes kept getting cold while finishing the outside. I wired the indoor panel while hot without any issues. I want to say that the vacuum was under 200 microns but the photo I took is on my phone which is now dead. So, confident with everything I released the refrigerant and put the valve covers back on. Of course the manual says put it in cooling mode but when it is 20deg outside the system does not run that hard. Heck the compressor sounded like it was running but no fan. Anyway, I switched to heating mode. I figure that less than 2 oz difference in the factory charge and the estimated charge I would need was not a big deal. Plus considering what I loose in the manifold.

I fired it up in heat mode and success. I did a test on the indoor temp and then the temp blowing out of the indoor head and we were at 112deg F. That was pretty good I think. It also made standing in front of the thing ****** uncomfortable. In fact I don't think the first floor heat pump has kicked in since. I can live with that. I will post more tomorrow!

Just did another thermometer test. The damn thing is blowing out 130deg F air. This thing is SICK!

 

[Kogashuko]

Just a quick update. Everything is working fine and no evidence of leaks. The average air temp coming out is around 100deg. This changes slightly with outdoor temp. If you put it in the chaos wind mode or it gets really cold out it ramps up and the air is around 130.

One think I notice which surprised me is that this unit comfortably heats the entire first floor. It also heats the stairway to the second floor. The stairway was always chilly or hot in the past. Setting the unit stat for 70deg keeps the first floor between 70 and 72 according to the stat in another room which connects to the rheem unit. The second floor stays at about 68 or 69 on the second floor stat which stays in the master bedroom behind a closed door. The second floor heat pump comes on in early mornings. I don't think the 2 ton first floor heat pump has come on since Saturday even when it was like 15 deg out!

 

[72puma]

just curious what model mini split are you using here?

 

[monkeyspanners]

Be careful putting a lot of pressure in the lines, it can leak into the outdoor unit and contaminate the refrigerant, generally i aim not to go to far above the standing pressure for the refrigerant at the ambient temperature you are working in.

 

[bazar01]

Be careful putting a lot of pressure in the lines, it can leak into the outdoor unit and contaminate the refrigerant, generally i aim not to go to far above the standing pressure for the refrigerant at the ambient temperature you are working in.

Basically this is the reason why I don't leave pressurized nitrogen for too long. The service valves may be closed but there is still the possibility the higher test pressure will bleed to the outside unit and mix with stored refrigerant due to lower standing pressure.
I just pull a vacuum and observe for pressure rise.
If I have to pressure test, it will be less than one hour for soap bubble test.

 

[High Point]

Came across this post looking for torque settings for various flare fitting sizes for mini spits. Old but UGGH! Concerning leak testing, the pros often have high end electronic gauges that can monitor for small leaks in a short amount of time. They have equipment and products that can measure .05% annual leak in minutes. Did you spend a few hundred $$$ for a high end electronic unit that has temperature probes, bluetooth/wifi links to your phone and professional diagnostic tools? Did you purge the air out of the lines before your CO2 test? Did you test for proper superheat or subcooling? The pros can do this in about two hours, and know how NOT to overpressure a unit. No, it will NOT cost you a few thousand to have one come over and do a proper pressure test and then a proper vacuum test to make sure of no leaks and no moisture and no air in the lines. The cost should be about $125 or so to protect your warrantee. Without initial servicing by a licensed professional, you may not have a warrantee.

 

[justinjoyal]

Came across this post looking for torque settings for various flare fitting sizes for mini spits. Old but UGGH! Concerning leak testing, the pros often have high end electronic gauges that can monitor for small leaks in a short amount of time. They have equipment and products that can measure .05% annual leak in minutes. Did you spend a few hundred $$$ for a high end electronic unit that has temperature probes, bluetooth/wifi links to your phone and professional diagnostic tools? Did you purge the air out of the lines before your CO2 test? Did you test for proper superheat or subcooling? The pros can do this in about two hours, and know how NOT to overpressure a unit. No, it will NOT cost you a few thousand to have one come over and do a proper pressure test and then a proper vacuum test to make sure of no leaks and no moisture and no air in the lines. The cost should be about $125 or so to protect your warrantee. Without initial servicing by a licensed professional, you may not have a warrantee.

- Bluetooth and other gizmos will not make a tech better.

- You cannot check for proper SH/SC on a mini-split.

 

[High Point]

True, but the better tools in the hands of an experienced tech can do the job correctly in a short time. Fifteen grand and fifteen miles don't make you a biker. Expensive tools don't make a tech. But an experienced tech with the right tools doesn't need days to prep a system, only a few hours.

And the vacuum does more than just check for leaks. That is the purpose for the nitrogen pressure test. The vacuum also removes moisture that might have entered the system. How long was the vacuum pump run? Long enough to draw down the system or long enough to remove any possible moisture in the system? A system can pass the vacuum test, but still leak because a vacuum can actually hide a leak.