setting suction pressure

[chadng]

Hi guys, i am currently working with a 3hp hitachi condensing unit, bohn let 120 evaporator and, danfoss ts2 TXV. currently i am getting 25psig (r404) suction pressure. I want it to go down to 20 psig (r404) suction pressure. how do i attain this? do i have to adjust the expansion valve?

[jpsmith1cm]

Is the box at temperature?

If not, wait until it is very close to temperature before adjusting anything.

[Brian_UK]

Is the TXV correctly sized?

[Gary]

The suction pressure is not something to be set. It will be whatever it needs to be given the current conditions.

Why do you want it to be 20psig?

[martinw58]

you do not set the suction pressure you set the super heat at the tev

[cma]

Hi guys, i am currently working with a 3hp hitachi condensing unit, bohn let 120 evaporator and, danfoss ts2 TXV. currently i am getting 25psig (r404) suction pressure. I want it to go down to 20 psig (r404) suction pressure. how do i attain this? do i have to adjust the expansion valve?

You don't set the suction pressure as previously stated, the suction pressure will vary depending on the load. If your superheat is set right the evap coil is doing all it can. Maybe you have other problems with this system. If you have all other temps/pressures etc and what you are trying to obtain temp. wise we can assist further. good luck