Mastercool 69788-A R134a RECOVERY_RECYCLE_RECHARGE - Manual (Page 10)

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of the screen. To deactivate the alarm, the filters will need to be replaced (see page 18, Replacing the dryer
filters.)
NOTE: It is good practice to change the Vacuum pump oil when the filters are being changed. (see page 17 &
18, Vacuum Pump)
LOW REFRIGERANT ALARM: Beeper and the LCD advise when the charging quantity set exceeds the amount of refrigerant available. The
minimum quantity of refrigerant is 4.50 lbs. If the gas available minus the charge quantity equals less than
4.5 lbs, 69788 will interrupt the attempt to charge and notify the operator that there is low refrigerant. At
this time it will be necessary to tank charge 69788 to approximately 12 to 15 lbs of refrigerant in order to
perform a charge. For instance, if the gas available is 9.50 lbs and the charge quantity is 1.80 lbs, then
9.50 lbs minus 1.80 lbs equals 7.70 lbs. 7.70 lbs is greater than 4.50 lbs so 69788 will perform the charge.
If the gas available is 5.90 lbs and the charge quantity is 1.80 lbs, then 5.90 lbs minus 1.80 lbs equals 4.10
lbs. 4.10 lbs is less than 4.50 lbs, so 69788 will not charge and will let the operator know that there is
insufficient refrigerant available.
PRELIMINARY OPERATIONS
Check that the main switch (Fig. 7-I, page 8) is set to 0. Check that all the machine valves are closed. Connect the machine to the electrical supply
and switch on. Check that the vacuum pump oil level indicator shows at least one-half full. If the level is lower, add oil as explained in the ROUTINE
MAINTENANCE section (page 16.) Check that in the new
oil container (Fig. 6-D, page 8) there are at least 3.4 oz. (100 cc) of the oil recommended
by the manufacturer of the vehicle A/C system. Check that the oil level in used oil container (Fig. 8-M, page 8) is less than 6.7 oz. (200 cc.) Check
the machine’s display to be sure there is at least 9 lbs (4.08 kg) of refrigerant in the tank. Should this not be the case, fill the on-board machine tank
from an external tank of appropriate refrigerant following the procedure described in the ROUTINE MAINTENANCE section (page 16.)
WARNING:
DO NOT STOP THE RECOVERY PROCESS. Stopping the recovery process will definitely cause damage to the Compressor and perhaps other
components. It will also cause the machine to fill up with unprocessed liquid refrigerant which will disable the machine from further use.
Damage due to STOPPING THE RECOVERY PROCESS could void the warranty.
AUTOMATIC PROCEDURE
In the automatic mode, the recovery and recycling, oil discharge, and vacuum operations are performed in a sequence automatically. New oil can
only be added after the vacuum pump has stopped. The machine then goes on to automatic refrigerant charging when the start button is pressed.
Connect the hoses to the A/C system with the quick-connect couplings, bearing in mind that BLUE must be connected to the low-pressure side and
RED to high pressure. Open the quick-connect valves. If the A/C system is equipped with a single quick-connect coupling for high or low pressure,
connect and open only the relative quick-connect coupling and hose.
NOTE: Should the automatic procedure be selected when the A/C system is empty, the machine will begin with the vacuum phase. When working
with A/C systems with a single high-pressure (RED) coupling, set the charging quantity at about 3 oz. (100g) more than the required quantity, since it
will be impossible to recover the residual refrigerant from the hoses after charging.
Check that the high and low service valves on 69788 front panel are closed. Start the vehicle engine and switch on the air conditioner (Only
if vehicle’s AC is operational. If AC is not operational do not perform this step). Allow both to run for about 5 to 10 minutes with the passenger
compartment fan at full speed. Switch off the vehicle engine.
The machine is equipped with a 4-line LCD display, maximum 20 characters per line. On the menu press the down arrow until the selected line
flashes; in this manual it is enclosed in quotation marks. Select the automatic procedure by pressing ENTER when “Automatic Procedure” flashes
on the LCD.
<AUTOMATIC PROCEDURE>
→ENTER→
<VACUUM XX MIN>
ASSISTED PROCEDURE CHARGING X:XX lb
NEXT MENU
Ref avail X:XX lb
Set the vacuum time by keying in the desired time. To accept the time value that is already there, press enter. The machine will automatically perform
a 2 minute VACUUM LEAK TEST when the time value is 11 minutes or longer. The VACUUM LEAK TEST will start after 10 minutes of vacuuming. If a
leak is detected the machine will notify the operator that a leak was detected and will not continue vacuuming. If no leak is detected, the machine will
continue vacuuming for the time remaining.
<VACUUM XX MIN>
→2→0→
<VACUUM 20 MIN>
CHARGING X:XX lb CHARGING X:XX lb
After vacuum time has been confirmed, the “charging x: xx lb” message will flash. Set the quantity of refrigerant to be charged, using one of the two
following procedures: