PRECAUTIONS
ATC-11
C
D
E
F
G
H
I
K
L
MA
B
AT C
SERVICE HOSES
Be certain that the service hoses display the markings described
(colored hose with black stripe). All hoses must include positive shut-
off devices (either manual or automatic) near the end of the hoses
opposite the manifold gauge.
SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to a
CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will
not properly connect to the CFC-12 (R-12) system. However, if an
improper connection is attempted, discharging and contamination
may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant flow electronically, the hose fitting must be 1/2″-16
ACME.
CALIBRATING ACR4 WEIGHT SCALE
Calibrate the scale every three months.
To calibrate the weight scale on the ACR4:
1. Press Shift/Reset and Enter at the same time.
2. Press 8787 . “A1 ” will be displayed.
3. Remove all weight from the scale.
4. Press 0 , then press Enter . “0.00 ” will be displayed and change to “A2 ”.
5. Place a known weight (dumbbell or similar weight), between 4.5 and 8.6 kg (10 and 19 lb) on the center of
the weight scale.
6. Enter the known weight using four digits. (Example 10 lb = 10.00, 10.5 lb = 10.50)
7. Press Enter — the display returns to the vacuum mode.
8. Press Shift/Reset and Enter at the same time.
9. Press 6 — the known weight on the scale is displayed.
10. Remove the known weight from the scale. “0.00 ” will be displayed.
11 . P r e s s Shift/Reset to return the ACR4 to the program mode.
RHA272D
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D
