10 Ton Trane split system?

Question

I have a 10 ton Trane A/C in my shop at work. They have put on a compressor and changed filter driers and changed the expansion valve. Still doing the same thing. It has about 110 lb of suction pressure and about 200 lb on the liquid side. Its been worked on my a few different people. I'm trying to get it fixed, and ideas what the problem may be?

Answer 1

return leak and i mean just that sounds like a gas furnace with combustible air sucking attic air with the unit runningtake a lighter to the platform see where the flame gets sucked to does your high side bounce up and down but you open the cabinet it stops ive seen 20 year old systems that every tech out there has missed that is your problem

Answer 2

Did you check the solenoids to feel if it is opening and closing. It should be in the line somewhere. Is the thermostat adjusted right. One s***w sets it to come on and the other sets it to turn off, Is all the Contact blocks working, sometimes they can go out and still look like new. Be Careful there are Safety rules to follow.

Answer 3

Could the indoor coil be plugged (dirty)?

New TXV does not mean Good TXV! I put 4 into a single unit to get one to work. These TXVs today are junk made in Mexico.

Is the TXV installed properly?

Is it the proper TXV?

Could they have installed it backward?

Is the suction balancing line brazed in correctly, or did they braze it closed when changing?

Is the temperature sensing bulb tight to the suction line and properly insulated?

What is the superheat and subcooling of the unit?

Is this one of those old style heat pump coils with the check valves bypassing the TXV for the heat mode? If so is the check valve stuck open bypassing liquid into the suction line?

Does this unit have unloaders? Could one be bad if they are installed?

Possibly a bad compressor valve?

Is there a hot gas bypass to relieve excess head pressure? Could it be stuck open?

Is the condenser coil clean?

If this is 3 phase, is the compressor wired properly?

Is the indoor blower motor turning the proper direction?

Just some thoughts!