Refrigerant
Precautions Removal / installation
AIR CONDITIONER
REFRIGERANT
PRECAUTIONS
1. Precautions for refrigerant
(1) Compatibility
(a) Parts that constitute the refrigerant cycle and the compressor oil have no compatibility between the HFC-134a (R134a) and HFO-1234yf (R1234yf) system and the conventional R12 system.
(2) Refrigerant HFC-134a (R134a)
(a) Be sure to use HFC-134a (R134a) for the refrigerant.
CAUTION:
·The gas is not poisonous or hazardous in normal operation. However, when exposed to fire or high temperature conditions (cigarette, kerosene heater, etc.), it may become hazardous gas.
·Pay attention to sufficient ventilation and do not work at a closed place.
·Pay attention to sufficient ventilation and do not work at a closed place.
NOTE:
The manifold gauge is specially used for HFC-134a (R134a) to prevent incorrect charge.
(3) Refrigerant HFO-1234yf (R1234yf)
(a) Be sure to use HFO-1234yf (R1234yf) for the refrigerant.
CAUTION:
·The gas is not poisonous or hazardous in normal operation. However, when exposed to fire or high temperature conditions (cigarette, kerosene heater, etc.), it may become hazardous gas.
·Pay attention to sufficient ventilation and do not work at a closed place.
·Pay attention to sufficient ventilation and do not work at a closed place.
NOTE:
The manifold gauge is exclusively designed for HFO-1234yf (R1234yf) to prevent incorrect charge.
(4) Compressor oil
(a) Use the specified compressor oil only.
HFC-134a (R134a)
: ND-OIL8
: ND-OIL8
HFO-1234yf (R1234yf)
: ND-OIL12
: ND-OIL12
NOTE:
If the compressor oil designed for R12 is used on a HFC-134a (R134a) and HFO-1234yf (R1234yf) systems, compressor lock due to poor lubrication or leakage of the refrigerant gas due to expansion of rubber part may occur. On the other hand, if HFC-134a (R134a) or HFO-1234yf (R1234yf) compressor oil is used in a R12 system, the durability of the A/C system will be reduced.
(b) The compressor oil for HFC-134a (R134a) and HFO-1234yf (R1234yf) has high hygroscopic property. If A/C parts are removed, immediately seal them with plug, vinyl tape, etc. from the atmosphere.
(c) The compressor oil for HFC-134a (R134a) and HFO-1234yf (R1234yf) may have adverse effect on acrylic resin. Do not spread the oil.
(5) O-ring
(a) Be sure to use the O-ring for HFC-134a (R134a) and HFO-1234yf (R1234yf).
NOTE:
The material, size, etc. of the O-rings for HFC-134a (R134a) and HFO-1234yf (R1234yf) and for R12 are different. Incorrect use may result in leak of the gas.
(6) Precautions for vacuuming
(a) For vacuuming, install a solenoid valve adapter on the vacuum pump for R12.
NOTE:
If you leave the system as it is after vacuuming without using the solenoid valve adapter, oil (for R12) in the vacuum pump may run reverse and flow into the HFC-134a (R134a) and HFO-1234yf (R1234yf) system.
(7) Check for refrigerant gas leak
(a) To check for refrigerant gas leak, use an electronic leak detector.
(b) Check for refrigerant gas leak with IG OFF.
NOTE:
·If the check is performed while the engine is running, leak gas is diluted by fan, blower, etc. and it becomes hard to detect a leak.
·If the check is performed while the cooler is on, the refrigerant pressure in the cooler unit is reduced. It inadequately prevents the gas leakage.
·If the check is performed while the cooler is on, the refrigerant pressure in the cooler unit is reduced. It inadequately prevents the gas leakage.
2. Precautions for assembly/disassembly
(1) Action when the refrigerant gas gets into the eyes
(a) Do not rub eyes with hands or a handkerchief.
(b) Take treatment from a special eye doctor.
(2) Precautions for handling of refrigerant gas (service can)
(a) Do not heat a service can. If a service can is directly heated or put in hot water, the pressure in the can become excessively high, resulting in burst of the can. If it is necessary to heat a service can, use warm water at 40°C or less.
(b) Do not drop or hit a service can.
(c) Do not open the high-pressure valve of manifold gauge when the engine is running. If the high pressure valve is opened while the engine is running, reverse flow of the high pressure gas may occur, resulting in burst of the can.
(d) Do not handle a service can near the face. Be sure to wear protective goggles.
(3) Pipe installation
(a) Be sure to use a new O-ring.
NOTE:
·Be sure to use the O-ring for HFC-134a (R134a) or HFO-1234yf (R1234yf).
·When removing the O-ring, use a soft tool like a toothpick so that a pipe may not be damaged.
·When removing the O-ring, use a soft tool like a toothpick so that a pipe may not be damaged.
(b) Apply compressor oil (ND-OIL8 or ND-OIL12) sufficiently to the O-ring.
(c) Route the hoses naturally and do not twist or bend them forcibly.
(d) If foreign matter like lint stays on the O-ring, it may cause leak of the refrigerant gas. Do not use cotton gloves.
ADJUSTMENT
1. Discharge of refrigerant HFC-134a (R134a) and HFO-1234yf (R1234yf)
(1) Operate the air conditioner under the conditions below.
| Conditions |
Contents |
| Engine speed |
Idling |
| Operation time |
3 minutes or more |
| A/C switch |
ON |
| Blower level |
HI |
| Setting temperature |
MAX COOL |
CAUTION:
If the air conditioner cannot be operated due to lock of the compressor, operation is not required.
(2) Stop the engine.
(3) Connect the CFC recovery system,and discharge the refrigerant gas.
CAUTION:
When using the CFC recovery system, use it correctly according to the operation manual.
2. Charging refrigerant HFC-134a (R134a)
(1) Using a vacuum pump, perform vacuuming.
(2) Charge refrigerant HFC-134a (R134a).
Standard value
Refrigerant charge level
: 390±50 g {13.76±1.76 oz}
: 390±50 g {13.76±1.76 oz}
CAUTION:
If the cooler compressor is operated without refrigerant, seizure may occur due to poor lubrication. Never operate it before charging of refrigerant.
NOTE:
If collected refrigerant gas is reused, the refrigerant gas recovery rate with a CFC recovery system is about 90%. Prepare a service can for refilling in advance.
3. Charging refrigerant HFO-1234yf (R1234yf)
(1) Using a vacuum pump, perform vacuuming.
(2) Charge refrigerant HFO-1234yf (R1234yf).
Standard value
Refrigerant charge level
: 350±30g {12.34±1.06oz}
: 350±30g {12.34±1.06oz}
CAUTION:
If the cooler compressor is operated without refrigerant, seizure may occur due to poor lubrication. Never operate it before charging of refrigerant.
NOTE:
If collected refrigerant gas is reused, the refrigerant gas recovery rate with a CFC recovery system is about 90%. Prepare a service can for refilling in advance.
Captions in illustration
| *a |
Charge level |
*b |
Center of appropriate values |
| *c |
Bubble disappearing point |
*d |
Over-charge |
| *e |
Pressure |
*f |
Sub cool system |
| *g |
Refrigerant level |
*h |
Cross range |
4. Engine warm-up
CAUTION:
After charging refrigerant, perform break-in operation at 2000 r/min or less for 2 minutes or more.
5. Check for refrigerant gas leak
(1) After charging refrigerant gas, use an electronic leak detector to check for leak of the refrigerant gas.