RHA273D
SERVICE COUPLERSNJHA0117S06Never attempt to connect HFC-134a (R-134a) service couplers to
an 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 contamina-
tion may occur.
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA274D
REFRIGERANT WEIGHT SCALENJHA0117S07Verify 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 1/2²-16
ACME.
CALIBRATING ACR4 WEIGHT SCALENJHA0117S09Calibrate the scale every three months.
To calibrate the weight scale on the ACR4:
1. PressShift/ResetandEnterat the same time.
2. Press8787.ªA1º will be displayed.
3. Remove all weight from the scale.
4. Press0, then pressEnter.ª0.00º will be displayed and change
to ªA2º.
5. Place a known weight (dumbbell or similar weight), between
4.5 and 36.3 kg (10 and 80 lb) on the center of the weight
scale.
6. Enter the known weight using four digits. (Example 10 lb =
ª10.00º, 10.5 lb = ª10.50º)
7. PressEnterÐ the display returns to the vacuum mode.
8. PressShift/ResetandEnterat the same time.
9. Press6Ð the known weight on the scale is displayed.
10. Remove the known weight from the scale. ª0.00º will be dis-
played.
11. PressShift/Resetto return the ACR4 to the program mode.
CHARGING CYLINDERNJHA0117S08Using a charging cylinder is not recommended. Refrigerant may be
vented into air from cylinder's top valve when filling the cylinder
with refrigerant. Also, the accuracy of the cylinder is generally less
than that of an electronic scale or of quality recycle/recharge
equipment.
PRECAUTIONS
Precautions for Service Equipment (Cont'd)
HA-7
