A/C - Recovery/Recycling Machine Usage Information

Classification:
HA93-009

Section:
Heater/Air Condit.

Reference:
TECHNICAL BULLETIN NTB93-096

Models:
All with R-134a Refrigerant

Date:
June 17, 1993

KENT-MOORE ACR4 MACHINE USAGE INFORMATION

APPLIED MODELS:
All Nissan Vehicles equipped with R-134a Refrigerant

SERVICE INFORMATION:

Based on service technician comments, this Bulletin will highlight some of the areas where caution is necessary to ensure the accuracy and proper operation of the Kent-Moore ACR4 Recovery/Recycling Machine. Please refer to the previously-issued Bulletin, "A/C System Changes for R-134a Refrigerant (All Models)" NTB93-001 (HA93-001). Also, additional information can be found in the appropriate Service Manual.

I. Tank Sensitivity/Charge Accuracy:

NOTE:
The following items must be observed to ensure accurate charging of the A/C system.

^ When transporting the machine to various service locations, ensure that the tank has not shifted or become cocked on the scale platform. Be certain that the tank is not touching the back bar.

^ During charging, even slight disturbance of the machine will affect the scale under the tank. When charging, do not place any objects on the machine; do not lean on the machine; do not bump the machine.

^ Keep the two (2) scale platform set screws tight.

^ When disconnecting hoses from the vehicle, the following procedure should be used to ensure that a minimum amount of refrigerant is left in the hoses:
-with the engine on and the A/C on [compressor clutch engaged], close the high and low side valves on the machine control panel.
-disconnect the high side hose coupler from the vehicle.
-open both the high side and low side valves on the control panel.
-close the high side and low side valves on the control panel and disconnect the low hose coupler from the vehicle.

^ Scale accuracy should be checked during initial machine set-up and rechecked every three (3) months. Refer to pages 15 and 16 of the ACR4 System Operating Guide. Please contact Kent-Moore (1-800-345-2233) if the machine accuracy is in question.

II. Error Codes/Operation Interruption

^ If, during machine operation, the "U-HI" error code is displayed, ensure that both tank valves are open and that all refrigerant has been recovered from the service hoses and internal plumbing.

^ If the charging process is interrupted, the principle reason is not allowing for the full 20 minute evacuation cycle. A shorter than 20 minute cycle does not allow the tank temperature/pressure to rise sufficiently to force the refrigerant into the vehicle. Other causes include poor machine cooling fan airflow or improper electrical connections. Make sure that the electrical cord is no less than No. 14 AWG and the service outlet is not overloaded.

III. Refrigerant Recovery Amount Accuracy

During A/C system operation, a significant amount of refrigerant is dissolved within the lubricating oil inside the A/C system. During refrigerant recovery, this refrigerant "boils" out of the oil (this process is referred to as "outgassing"). Outgassing can be accomplished more quickly if, before beginning the recovery operation, the vehicle A/C system is operated for about 10 minutes with the engine at normal operating temperature and the hood closed. If A/C system or engine operation is not possible, the outgassing will still occur, but at a slower rate, when the pressure within the A/C system falls into a vacuum.

Insufficient amounts of recovery time will result in less than the complete refrigerant charge being removed from the system.

IV. Machine Maintenance

^ Proper routine maintenance is essential to keep the machine in good operating condition.
^ The vacuum pump oil should be changed every 10 hours of pump operation (refer to Operating Instructions, p. 12).
^ The filter should be changed when the moisture indicator fails to turn green during recycling
(refer to Operating Instructions, p. 13).
^ Scale calibration should be performed every three (3) months (refer to Operating Instructions, p. 15).

V. Minimum Amount of Refrigerant Required for Machine Operation

A minimum of approximately six (6) pounds of refrigerant is required in the tank for the machine to operate. If the "check refrigerant" message appears, the amount of refrigerant in the tank may have fallen below the required minimum amount needed for machine operation. (refer to Operating Instructions, p. 11).

NOTE:
If you need technical assistance (or additional copies of the ACR4 Oiler in Instructions), contact Kent-Moore by calling 1-800-345-2233).