And I thought it was just bad filter driers spilling their guts. It's obviously much deeper than that...
This reminds me of quite a few rtus I could never get quite right. high SH, low suction, high head. Clean clean clean the coils. Can't even imagine how you guys keep em going in the really hot climates.
This problem has been going on way too many years! Come on Trane and fix this crap once and for all for crying out loud. I won't recommend these units to my customers because of the continued failures.
You could try it that way, but I assure you, I have worked on over 250 of these units (NO JOKE) for the factory and you cannot, cannot, cannot make these units run properly without replacing the 16in3 drier with a 30in3 drier and installing a txv. I have replaced driers on about 30 units, returned 4 months later and they are stopped up again. completely. Run superheat test over a period of three months after you clean the BRASS orifices (which I would not heat under any circumstances) and watch, even as the ODA increases, superheat will likely increase also. Ive seen These machines run about 45 deg superheat on a 65 degree day, the oil is wrong, the charge is wrong, the driers are wrong, the compressors are wrong...Put a TXV in and you wont have to keep on working on the unit, otherwise you will spend many many man hours on call backs.
One note, the compressors are not designed to run over 20 degrees superheat at the compressors...how can they achieve that SH besides a TXV? the orifices obviously cannot do the job
Add 2 lbs of R22 when you replace the drier. Total charge should be (i think) 28 lbs in the 10 ton circuit.
No cheap way around it man, it might be cheaper to replace the headers, but they'll just stop up again.
[Edited by bdclark on 10-02-2006 at 04:14 PM]
Looks like you've done a lot of txvs on these. I've done a few. Curious about the distributor tubes. Do you try to keep them all the same length or cut 'em and make them look neat? Does it really make any difference?
Do it by the book and replace the header and install a txv kit. Im telling you it will save you time and money in the long run. Make sure you get an over sized liq. line drier and suction core to catch all the crap floating around the system. Tell the customer to get a move and cool unit...
I've done a few conversions, I always let the local Sporlan sales rep. do the sizing for me and I buy the parts from United, it takes me about 8 hours to complete the job from beginning to end, I use 15% rod for all copper to copper braze and Staybrite 8 for brass to copper.
after going from orifices to TXV the refrigerant (name plate) charge diminish even with the larger dryers.