Carrier 17/19EX - Manual (Page 198)

Refrigerant Tracer
Use an environmentally acceptable refrigerant as a tracer for leak test procedures.
To Pressurize with Dry Nitrogen
Another method of leak testing is to pressurize with nitrogen only and use a soap bubble
solution or an ultrasonic leak detector to determine if leaks are present. This should only be
done if all refrigerant has been evacuated from the vessel.
1. Connect a copper tube from the pressure regulator on the cylinder to the refrigerant
charging valve. Never apply full cylinder pressure to the pressurizing line. Follow the listed
sequence.
2. Open the charging valve fully.
3. Slowly open the cylinder regulating valve.
4. Observe the pressure gage on the machine and close the regulating valve when the
HFC-134a MUST NOT be mixed with air or oxygen and pressurized for leak test-
ing. In general, this refrigerant should not be allowed to be present with high con-
centrations of air or oxygen above atmospheric pressures, as the mixture can
undergo combustion.
WARNING
!
WARNING