PREPARATION — Service Tools (Cont'd) — Vacuum Pump / Gas Leak Detector
HA-12prose procedureService Tools (Cont'd)
Vacuum pump
The vacuum pump is used to purge air and moisture from the inside of the refrigeration system by evacuation, thereby ensuring proper functioning of the air conditioner system.
IMPORTANT
Check the vacuum pump to see that the vacuum pump capacity is greater than -100.0 kPa (-1,000 mbar, -750 mmHg, -29.53 inHg).
Vacuum pump performance check procedure
Vacuum-pump performance check
- 1Connect the vacuum gauge to the system.
SHA458D - 2Run the vacuum pump, and check to see that the needle pointers of the gauge manifold and vacuum gauge move smoothly, indicating a similar value.
- 3After running the vacuum pump for two or three minutes, read the vacuum gauge. The measured value indicates the capacity of the vacuum pump.
Gas leak detector
The gas leak detector is used to check whether the refrigeration system is leaking. The features of this gas leak detector are listed below.
Gas leak detector types
Electrical
Sub-typeDischarge type (Suction type)
Detection ability3 - 50 g (0.11 - 1.76 oz)/year
FeaturesEasy handling; Medium sensitivity; Each point needs two or more seconds for detection.
Electrical
Sub-typePositive ion emission type (Suction type)
Detection ability2 g (0.07 oz)/year
FeaturesHigh sensitivity; High price; Warm-up time is needed because a heater is incorporated.
Other simple checking method: Change in vacuum when evacuating
Sub-type
Detection ability1 kg (2 lb)/month; if 13.3 kPa (133 mbar, 100 mmHg, 3.94 inHg) change in vacuum is detected in 10 minutes.
FeaturesCan be used easily in refrigerant charging operation. Detection ability is very low with vacuum gauge in gauge manifold.
IMPORTANT
Leakage inspection of a refrigeration system needs a sensitivity greater than 20 g (0.71 oz)/year.
The actual amount of leak is estimated at 5 to 10 times the detected amount.
Insufficient cooling may be felt if leakage exceeds 150 to 200 g (5.29 to 7.05 oz).