THE REFRIGERANT SYSTEM
This task covers:
Tool kit, refrigeration SVC
General Safty Instructions
Voltages used can kill. Always disconnect power
cord to air conditioner before performing any
internal maintenance. Shutting unit off at its
control panel does not disconnect unit power.
Nitrogen is an inert gas. However, it also presents danger as a suffocant and, therefore, must also be
discharged in a ventilated location.
Nitrogen cylinders are pressurized containers. The pressure in the cylinder can exceed 2000 psi. A
nitrogen pressure regulator should be used at all times when nitrogen is used for leak check or purge
The refrigeration system must be purged with dry nitrogen, Item 9, Appendix E, before any brazing is
performed on any component. A flow of dry nitrogen between 1 and 2 cfm (0.028-0.057m3/minutes)
should be continued during all brazing operations to minimize internal oxidation and scaling.
a. Connect the center hose from the charging manifold to a nitrogen regulator and dry nitrogen tank.
b. The hose from the high pressure service valve to the charging manifold must be connected.
c. The hose from the low pressure service valve must be disconnected from the charging manifold.