Robinair 34788-I Recovery, Recycling, Recharging Unit - Manual (Page 11)

9
539602 Rev. H June 11, 2013
Operating Instructions
Evacuate the A/C System
1. Ensure service hoses are connected, and coupler
valves are OPEN.
2. Press VACUUM.
3. Press START / YES to accept the default evacuation
time of 10 minutes, or enter the desired vacuum time
using the number keys, and press START / YES.
IMPORTANT: The unit pulls a vacuum on the
vehicle A/C system to remove air and boil off
moisture that may be present in the system.
Evacuate the system for at least 10 minutes,
or follow the A/C system manufacturer’s
specifications, to ensure adequate moisture and
contaminant removal.
4. The unit gives you the option of doing a leak test
after evacuation.
Press START / YES to perform the leak test.
Press STOP / NO to skip the leak test and begin
evacuation.
5. The unit evacuates the A/C system and stops when
the specified amount of time has elapsed.
Press STOP / NO to pause the process. Press
START / YES to resume, or STOP / NO again
to exit.
You are now ready to replenish the A/C system with
new oil, if necessary, or to recharge the system with
refrigerant.
Operating Tips
• If the vacuum pump has run for 10 or
more hours without an oil change, the
unit displays
VACUUM OIL TIME XX:XX
CHANGE OIL NOW?
Refer to instructions outlined in the
Maintenance section under Change
Vacuum Pump Oil.
• Before the unit begins evacuating the A/C
system, it checks for any pressure in the
system that might damage the vacuum
pump. If pressure is detected, the unit
displays
PRESSURE EXISTS
PRESS ANY KEY TO EXIT
Press any key to exit, and recover
refrigerant before proceeding.
• If a leak test was selected at the end of
vacuum, and a leak is detected, the unit
displays
LEAK TEST FAILED
PRESS ANY KEY TO EXIT
Press any key to exit the evacuation,
perform needed repairs, and repeat the
evacuation.
• To ensure an accurate leak test, it is
imperative that a thorough recovery and
evacuation of the system be performed.
During the recovery process, cold spots
can develop in the automotive system.
Pockets of refrigerant in desiccant and
in system oil will continue to vaporize as
the A/C system temperature equalizes
toward ambient. As this occurs, A/C
system pressure will increase, which may
be interpreted by the unit as a leak.
This will vary somewhat with ambient
temperature conditions.