Do I need to remove all of the refrigerant from the NRL unit when changing the pressure controls of transducers?

Chillers, free cooling units, heat pumps

The low pressure and high pressure transducers can be removed from the system without removing the charge from the system as they are fitted with a schraeder check fitting. Units that are fitted with a low pressure switch from the factory are also equipped with a schraeder check valve. By code the manual high pressure switch is not fitted with a schraeder check valve. See below for further details on changing the AP (HP).