Carrier A/C, Again!

[Nandy]

Re: Carrier A/C, Again!

Yes, there is one but Im not sure they will sell it to me but I have not tried, I guess I need to cross that bridge first.

 

[bigdee]

Re: Carrier A/C, Again!

Try Johnstone 3610 Century Place
Charlotte, NC 28206-1607
Phone (704) 632-1645
I have used them a number of times. How is that unit doing in this 100 degree heat? IMO if that unit is more than 10 years old and it is cooling and the suction line is cool and sweating all the way back to the compressor shell and the RLA is close to normal you might want to consider leaving well enough alone. Brazing the lines again without using dry nitrogen is risking the chance of the copper flaking (which might be the problem now). I know you sound like myself who wants everything to be dialed in perfect. As a former HVAC and commercial refrigeration contractor I have seen plenty of mismatched systems in the field that had been chugging along for years. Can you give an update on the Liquid and suction pressures? Also feel the top of the compressor shell with your hand...if you can't hold your hand there for very long it means your not getting enough suction cooling,in which case you will need to move on to plan B....good luck! You can buy a brand new 3 ton R-410 split system AC for around $1100 with a 10 year warranty.

 

[Nandy]

Re: Carrier A/C, Again!

I will look into the details of your post Bigdee. The valve I have now is a ea36yd-045 it also has a reading that indicates ps42 bar/mwp 510 psig. I called the shop but they wont sell anything to me. You guys have to remember I am not a contractor and most established shops will not sell anything to me. That is why I go the craigslist, ebay or inline route... Thanks for the help. I will keep looking online.

 

[Nandy]

Re: Carrier A/C, Again!

There is another parts house wants the part number for the valve so if any of you guys has one or 2 part numbers please let me know what it is to see if they can get me one.
Thanks!

 

[Tim Frank]

Re: Carrier A/C, Again!

This one maybe?
http://www.alpinehomeair.com/viewproduct.cfm?productID=453062864

But I'd wait for a second opinion from one of the pros.

The expert opinion was that your current TXV is undersize....I'd consider going a shade oversize and installing a manual liquid valve ahead of the TEV.
Given that this is becoming a bit of a "hybrid" system you don't want to put in a TEV and find it is still undersize....they won't take it back.

That would give you coarse adjustment...which you would never touch once set. The TEV would be your fine tuning.

I have done this in the field....once; and it worked great. But again, wait for a currently active pro to comment. I might have just gotten lucky...

 

[Nandy]

Re: Carrier A/C, Again!

The numbers are:
Outside temp 100.4
Suc temp 66.2 (under the line insulation)/71.6 (on the expose line)
Liqu temp 107.6
Fan temp 116.6
Suc PSI 77
Liqu PSI 300
Register temp 64.4
Return temp 77, Which is also the average temp at the house. I have set the thermostat to 74 deg.

The neighbors system which is the same of what I have and still stock system looks as follow:
suc temp 57.2 (under the line insulation)
liqu temp 109
fan temp 114.8

I did not dare hook to her system to check the psi and have no access to the inside. Just thought I gave those numbers to compare. Her house is also smaller and the load in the system is .4 lbs less than mine so I dont think there is much difference to worry about. Her outside unit is also in the shadow where mines is under the sun all the time, not sure that will make a lot of difference, I will think not...
I will check into that valve later but I noticed it is a 3.5+ ton system so that exact one would not fit. Any other part numbers will be welcome. If I find anything else I will post it here...
Thanks everyone!

UPDATE: I saw the Danfoss tr6 - 067l5857 which is 2.5 - 3 ton. I should had looked more... I called the shop but it seems they are gone. Will try again tomorrow... Would I be wrong in assuming that if this TXV is still not large enough after adjusting I can anyway ad that manual valve right? Will adding the manual valve to the original non-adjustable valve be an option?
As far as brazing the parts in and the copper flaking, what are the alternatives?

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

You just need a Sporlan 3 ton to 3 1/2 ton valve...I talked to ARS in scottsdale AZ, and if you call them and pay with a C/C they will ship you the parts you need...You have to pay for the parts + tax + shipping, but you can do it through my company account...

The parts are...

cartridge p# bqc-c
body p# EBQE38x12odf
power head p# kt43vga

and the price...
93.32 + tax + shipping

PM me if its something you want to do, and I can set you up with them...

PS with those readings you are running 21 degrees of superheat and 25 degrees of subcooling with a 7.2degree condenser approach...That machine is a 4 seer at this point, and all the refrigerant is in the condenser...Seeing how you have a larger indoor coil and an excess of refrigerant in the outdoor coil you can't deliver to the indoor, its pretty cut and dry your txv isnt opening wide enough or is bad...

 

[bigdee]

Re: Carrier A/C, Again!

hrdwrkingacguy, you definitely know your stuff and I agree with you on the expansion valve. It is also possible that overheating while brazing could have contaminated the valve. Nandy, if you are using sil-fos 15 it will melt around 1200 degrees and flow at 1400,it is important not to heat the joint much above this point....work quickly and keep the torch tip moving to evenly spread the heat. Sil-fos 6 has a slightly lower flow temp but I don't think it would make much difference. There are some low temp solders in the 500 degree range but I never felt comfortable using it on the high side of R-22 systems. After you remove the old txv it would be a good idea to swab clean the inside of the tubing to remove any oil traces so it won;t turn to crud when you braze.

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

The less silver the rod has the harder it is to flow...The joint needs to be cleaner, so it may be lower temperature but you have to hold the heat to it longer and screw with it more...In the long run 15% is the way to go unless you want to buy 45% and the white flux paste...You can connect pot metal to aluminum siding with that if you know what you are doing...

 

[Nandy]

Re: Carrier A/C, Again!

Thanks guys. Right now I have to put this on hold again. I'm on my way to VA on an emergency situation again. Don't know when will I be back or how much money I will have when I get back. Will keep you posted.

 

[Nandy]

Re: Carrier A/C, Again!

The parts got here yesterday. I am confident I can put it together but just to be sure here is what I got.

Thanks!

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

That looks like everything you need...You can braze in the body then build it or build it, wrap it really well with a wet rag and then braze...The cartridge goes where the red cap is...Its a good idea to put some refrigerant oil around the teflon rings on the cartridge before you assemble it(but that may not be an option if you don't have access to any)...Make triple sure the spot where you mount the bulb is clean and sanded and it's installed in a horizontal pipe run between 10 and 2(Basically on top of the line where its the warmest)...Wrap the copper straps around the pipe and the bulb and form it to the shapes and use the hole that are the farthest apart the bolts will reach to still get a nut on and make sure its really tight...You shouldn't be able to turn it by hand when its attached to the pipe...The bulb can go outside of the unit if need be, just insulate it with foam tape from home depot...The instructions show where to put the equalizer line in relation to the bulb...Typically its between the coil and the sensing bulb...Whatever you do don't drill a hole in the line for the equalizer line...If you have an oxy/acetylene torch just turn up the oxygen a little till the tip is really white/blue and sharp and burn a hole, so no shavings screw up all the work you are doing...

I don't remember if you put your drier in yet but if not I would put it outside the indoor unit so its close to the txv with the arrow pointing to the indoor coil...

PS one last piece of advice, this valve and an arrow on it on the body...Make sure it points to the indoor coil...And this valve is replacing the one in the unit, so in needs to go in the same place as the old one...Hopefully you can get it in where the bottom adjustment nut is accessible to adjust it...

 

[Nandy]

Re: Carrier A/C, Again!

Planing to do this tomorrow as it will be a cool dry days. So, after I change the valve and make everything normal how do i adjust it? do I start with it wide open, mid or "closed"? When I installed the system I added the 4.6 or so lbs of freon but since this system is larger should I ad any more? Do you recommend me to recover the freon, vacuum the system the add more freon? I will think the freon in the system is fine but I would like to hear any input. I rather try to get this working so I have ac for the rest of the weekend and I know this is a bit late but it's been a long week and have been tied up with more stuff that what y'all want to hear...
I believe the thermostat I am replacing has all the same parts I have in this new one, so I guess I can just locate this new bulb where the old one is and place the equalizer line where the old one is screwed in?

Thanks...

 

[Nandy]

Re: Carrier A/C, Again!

Now that I am thinking, I dont remember that new valve having a equalizer line, I hope the one I have in the old one fits it... Im at work so I cant double check. This is the valve I have there now...
http://cgi.ebay.com/FAST-1174451-2-3-TON-TXV-KIT-R22-19990-/200623096929

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

The new one goes where the black cap is...Its 1/4" copper and needs to be hooked up...When you get it all together run the system and check the suction pressure...Convert that pressure to a temperature with a pressure/temperature chart...Gauges typically have one on them...Suction line temperature - suction saturation temperature = superheat...See what you have, if its < 12 loosen the adjustment nut a 1/2 turn at a time...If its > 12 tighten a 1/2 turn at a time...

Keep in mind the changes do not happen immediately...You need to have the panel back on the unit and let it stabilize for a minute or two after an adjustment...

 

[Nandy]

Re: Carrier A/C, Again!

understood, but I dont remember the package having the line and connector for that. I should be able to use the old line right?

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

I wouldn't use the line from the old valve its 1/8"...Get a small piece of 1/4" copper...Home depot sells rolls of 1/4" for swamp cooler water lines...You don't need 25' but you do need that line hooked up...The valve won't work without it...

 

[Nandy]

Re: Carrier A/C, Again!

I deleted the previous question....
So after I set the valve using superheat I can use subcooling to make sure my load is correct, is that the right order?

 

[hrdwrkingacguy]

Re: Carrier A/C, Again!

no its gauge pressure converted to temperature with a chart...

 

[Nandy]

Re: Carrier A/C, Again!

got it, just deleted that question... I have read a bit more and im getting a better handle to this. So after I set the valve using superheat I can use subcooling to make sure my load is correct, is that the right order?