MAHLE RTI Matco AC880 - Manual (Page 4)

Page 3
USING THE AC880
Note: The purpose of this discussion is to familiarize the user with the features and functions of the AC880 Refrigerant
Handling Station. The procedures discussed in this manual assume that the AC880 has been set up in accordance
with the figures which are referred to and that the AC880 has been connected to the proper power supply. This
manual does not illustrate correct A/C service but rather how to correctly use the AC880.
The AC880 is microprocessor controlled with a menu driven user interface. All of the functions of the AC880 are accessed
by pressing a few simple key strokes and following the prompts. The on board Charging Cylinder is attached to a strain
gauge measuring device and the weight is electronically displayed.
The AC880 has a Fill Cylinder feature that allows refrigerant to be loaded directly into the Charging Cylinder without going
through the normal Recover/Recycle mode. When selected, this feature allows the AC880 Charging Cylinder to be re-filled
in just a few minutes at which point it will automatically stop at approximately 35 lbs (16 Kg.)
The AC880 Recovers and Recycles simultaneously in a true “single pass” through the filters and stores the refrigerant in
the Charging Cylinder where it is immediately available for use. This process automatically stops at 39.5 lbs (18 Kg) or
when a 15"Hg (-0.5 Bar) vacuum is sensed. The AC880 will wait for a minimum factory default of two minutes for “out
gassing” and cold refrigerant to raise the pressure back up to 3 psig (0.2 Bar) which would cause the Recover/Recycle
process to start again and reset this two minute Recycle Hold Timer before displaying that the process is complete. The
Recycle Hold Timer can be changed every time a Recover/Recycle procedure is run. Longer times should be selected on
colder days or on A/C Systems with large liquid capacities. Increasing this value may increase total time to
Recover/Recycle while decreasing the time may result in an incomplete Recovery of the A/C System. Refer to the chart
below for guidelines on setting the Recycle Hold Timer. The value entered is stored in the memory of the AC880 and
becomes the “default” value each time it is set. Non-Condensable Gases are vented automatically during
Recovery/Recycle. The Amount of refrigerant Recycled is displayed at the end of the procedure. This value is added to
the Total amount Recycled and stored in the memory of the AC880 (see Accessing Stored Data on Page 12.)
Temperature < 50F (10C) 50F (10C) to 80F (26.5C) > 80F (26.5C)
Recycle Hold Time 10 min 5 min 2 min
An integrated 7 CFM rotary vane style Deep Vacuum Pump draws on both the High and Low Hoses, ensuring complete
evacuation of the A/C System. The amount of time that the Vacuum Pump has been programmed to run will “count down”
on the display. The value entered is stored in the memory of the AC880 and becomes the “default” value each time it is
set. The Low Pressure Gauge can be used to monitor a rise in A/C System pressure. When programmed to do so, the
AC880 will pause and start a “count up” timer indicating how long the Vacuum Pump has been off, thus allowing the
operator to determine if a vacuum leak is present based on increasing pressure over time. A rapid rise in pressure indicates
the presence of a large leak that should be repaired. A slow rise in pressure may simply indicate that a longer Recycle Hold
Timer or Vacuum Time value should have been entered. A relatively constant vacuum reading over a long period of time
(less than 2 InHg [0.07 Bar] rise over ten minutes) is the most accurate way to check for vacuum leaks. The AC880 can
also be programmed to pause to allow oil to be added, and to the A/C System after vacuuming and prior to Charging.
Charging is done via the on board Charging Cylinder. The A/C Capacity is entered via the Keypad. The value entered is
stored in the memory of the AC880 and becomes the “default” value each time it is set. The AC880 can dispense liquid
refrigerant through either the High or Low Side Hose by changing the position of a selector switch. As refrigerant leaves
the AC880, the display will show an increasing weight to the programmed charge amount plus a factory set 0.03 Kg (one
ounce) Over Charge Amount necessary for compensation of refrigerant loss in the hoses. This Over Charge Amount can
be changed to accommodate different operating conditions (see Setting Over Charge Amount on Page 13.) An integrated
Heater automatically engages whenever Charging occurs. The Amount of refrigerant Charged is added to the Total amount
Charged and stored in the memory of the AC880 (see Accessing Stored Data on Page 12.)
The AC880 can be programmed to perform the Recover/Recycle, Deep Vacuum and Charge in a completely Automatic
mode. The AC880 will always go through the Recover/Recycle procedure, but will go immediately to the Recycle Hold
Timer if the A/C System is empty. The following matrix outlines the most commonly used options that can be programmed
to occur after the Recycle Hold Timer “times out”:
Recover/Recycle X X X X X X X X
Deep Vacuum X X X X X X
Vacuum Leak X X X
Add Oil X X
Charging X X X X X