Air Conditioning - Problem with older Trane model XE1000

New guy here. I have a Trane A/C split system model XE1000 R-22 system. Initial problem was that the compressor was making a hissing sound and both hi and low side pressures were doing absolutely nothing. Determined bad valves for the compressor.

Installed new compressor from Trane and changed out Liquid line drier. Turned unit on and the same sound hissing sound was coming from the compressor. RLA is 17A, units amps at start up is 25A and rises to about 28A then finally kicks off on safety. Low side pressure starts at 100psi and rises slowly to 110psi then cuts out on safety. Hi side starts at 150psi and rises to about 170 psi till it kicks off on safety. I don't feel I overcharged the unit because of the long run between the evaporator and condensing unit. but if it is overcharged, why would my head pressure be so low. Any help would be greatly appreciated.

What is being used for metering device?

You a service tech or homeowner that did a change out yourself?

What is being used for metering device?

You a service tech or homeowner that did a change out yourself?

Did it myself with some help from my buddies lifting that sucker on the roof. It's a 14 year old unit. Metering device is an expansion valve. I work for a hotel here on Maui in the maintenance department.

I am guessing that the TXV is stuck open since your low side is that high.

If I understand correctly, the compressor goes into bypass as soon as it's turned on? And then shuts off within a short time?
When a compressor is in actual bypass, the high side becomes lower than normal and the low side becomes higher than normal. This combined with higher than normal run amps would make me suspect there may be non-condensibles in the system (air), or the system may be grossly overcharged and possibly restricted.

I could be wrong, but I would explore these possibilities. Others feel free to jump in and correct me.

Im with Jim here : Sounds like it has contamintaes in it like non condensables or moisture. Id do a full recovery ,pull it down and recharge it . Also a new Liquid line drier.

Thanks for the feedback. You guys are on it.

After troubleshooting further, the factory installed drier located directly at the outlet of the condenser is the cause of the problem. Keep in mind that there are 2 driers between the outlet of the condenser and the expansion valve. The first that is factory installed and the 2nd drier which I replaced during the intitial compressor change out. Here's what I did.

After recovering the refrigerant. I disconnected the discharge line fitting from the compressor. I closed off the manual shutoff/service valves, located before and after the 2nd liquid line filter drier. Then I let 200psi of nitrogen in my high side port located on the liquid line between drier 1 and drier 2, so ofcourse the nitrogen went backwards through the first drier, condenser and exited through the inlet of the condenser at the compressor.

When I put my finger on the inlet of the discharge line, I could actually hold 200psi of nitrogen with my finger tip. Which indicated a major restriction between the inlet of the condenser and the manual shut off valve at the 2nd liquid line drier. Obviously the only place the restriction could be is at that first drier located at the outlet of the condenser.

Now I'm wondering if I could just eliminate that first drier and replace it with a staight pipe since I already have the second drier down the line? More importantly are the valves on this compressor still functional even after it's been through bypass? Thanks again guys.

You can eliminate the factory drier if you installed another. You are pulling this thing down into a vacuum right ?

P.S. Can I get a free week at the Maui hotel you work at ? :D

Glad you found the problem. I too, would replace that internal dryer with a pipe. You only need one liquid line dryer and having it outside of the condensing unit makes life easier for future service.
One tip: be really careful around those aluminum consenser tubes. Be sure to cover them with plenty of wet rags when you do the brazing.

Thanks guys! I will absolutely put it in a vacuum prior to charging. And the tip with the rags is greatly appreciated jim-connor. By the way mattison I can't get you a free week but I might be able to get a deal on a family rate.You'll be my uncle or something like that. Check out the Ritz Carlton Kapalua website

www.ritzcarlton.com

Aloha!

Just for back up you might have put in a suction line filter drier in at this time If any thing else is in the system.
It is always a good point to just feel the drier in a unit with your hands. It can tell you a lot