AIR CONDITIONING
32
11.12 DISCHARGING THE SYSTEM
REFRIGERANT RECOVERY
Various Refrigerant Recovery Units (RRU ) are
now available. The following procedure is typical
for the use of these units when recovering
refrigerant from a car air conditioning system.
1. Connect the RRU outlet to an R 134 a
recovery cylinder with a refrigerant hose and
open the valve on the cylinder. Ensure that the
cylinder has sufficient capacity to hold the
refrigerant in the system to be serviced. This
can be confirmed by weighing the cylinder or
by referring to the volume gauge if fitted.
2. Connect a gauge manifold set to the car air
conditioner. Connect to both the suction and
discharge sides of the system. Connect the
centre hose of the gauge set to the inlet of the
recovery unit. Connect the RRU to electrical
supply.
3. Open the gauge set and quickly connects stop
taps to allow refrigerant to enter the RRU via
the centre hose. At this point, depending on
which unit is being used, the RRU will switch
on. If the RRU is not the automated type,
which the unit on.
4. The automatic recovery unit will operate until
the air conditioning system has been emptied
of refrigerant down to atmosphere pressure.
The cylinder can now be closed. 5. Measure
the amount of PAG (Poly Alkaline Glycol) or
equivalent oil removed from the A/C system.
This oil is normally separated from the
incoming refrigerant into the RRU. New clean
PAG oil must be added into the system before
recharging with refrigerant.
