I am installing a carrier 24vna9 2 ton variable speed inverter driven AC with a 2 ton A C sized evap coil with a 2 ton txv. The infinity thermostat calls for 6lb 8oz with 40 ft of 3/4 line set. The evap coil is a brand new goodman c size A coil aluminum for 410a. I used a goodman because carrier did not have a 21in 2 ton coil to fit the current furnace and duct work. I have a 1.5 - 2 ton adjustable TXV installed (yes piston was removed) The furnace / air handler is a carrier infinity communicating 80k btu ECM blower. I evacuated the system to 350micron and it held under 450 for 10 min then charged with 5lb 10oz with unit off which is all it would take not running. This was with the service valves open and the condenser had been recovered prior to hookup. I waited a few days for the outside temp to rise above 80 and then ran the unit in charging mode and the stat indicated it went into high torque lockout after about 10 min. I waited the two hour lockout period and then ran it again and able to add about 8 more oz 410a in the suction line before it locked out again. The current total charge is about 6 oz short of the thermostat spec. Would this small under charge be enough to cause the high torque lockout twice? I forgot to mention I pressure tested the system to 455psi nitrogen and it held for several hours with no drop.
Last gauge readings I got was about max 4 deg sc and avg 10 sh. These were at stages 1 or 2 because the unit ramped down fast so I could not get a reading at stage 5 (full power). I checked the filter drier and its less then 1deg delta in vs out and its sized for a 4 ton so plenty of capacity and yes its the correct direction.
I have good airflow in the furnace with a new filter and the outdoor unit is clean and has good airflow as well.
The condenser unit is used. I saw it running on the old site and it was working then. It was pumped down and stored about 5 months before I installed it here.
The service manual suggests to look for wiring issues and that the unit may be overcharged.
At this point I don't know if I should keep trying to add refrigerant after each lockout period or try something else.
Thank you for any helpful input.
Last gauge readings I got was about max 4 deg sc and avg 10 sh. These were at stages 1 or 2 because the unit ramped down fast so I could not get a reading at stage 5 (full power). I checked the filter drier and its less then 1deg delta in vs out and its sized for a 4 ton so plenty of capacity and yes its the correct direction.
I have good airflow in the furnace with a new filter and the outdoor unit is clean and has good airflow as well.
The condenser unit is used. I saw it running on the old site and it was working then. It was pumped down and stored about 5 months before I installed it here.
The service manual suggests to look for wiring issues and that the unit may be overcharged.
At this point I don't know if I should keep trying to add refrigerant after each lockout period or try something else.
Thank you for any helpful input.
