94
8. Next, insert a small amount of same refrigerant into the system through the centre hose, until the pressure
reaches about 1MPa (10 BarG).
2
2
N
2
R-###
(Low/Gas)
pressure gauge
(High/Liquid) pressure gauge
An example illustrations of setup for
refrigerant leak detection.
3
7
4
8
Step 2: Refrigerant leak detection through Electronic halogen leak detector and/or ultrasonic leak detector:
1. Use any one of below detector to check leaking.
Electronic halogen leak detector.
Switch on the unit.
Cover the test area from direct draft.
Pass the detection probe near test area and wait for audible and visible signals.
Ultrasonic Leak Detector
Make sure the area is quiet.
Switch on the ultrasonic leak detector.
Move the probe along your air conditioning system to test for leaks, and mark for repair.
2. Any leak detected at this level shall be repaired and retested, starting from “Step 1: Pressure test”.
NOTE:
Always recover the refrigerant and Nitrogen gas into recovery cylinder after completion of a test.
You must use the detection equipment with Detectable Leak Rate of 10-
6
Pa.m
3
/s or better.
Do not use refrigerant as test medium for system with total refrigerant charge more than 5kg.
Test shall be performed with dry Nitrogen or another non-flammable, non-reactive, dried gas. Oxygen, air or
mixtures containing them shall not be used.
Step 3: Vacuum test:
1. Perform Vacuum test to check leak / moisture if present.
2. Refer to section “EVACUATION OF THE EQUIPMENT” to vacuum gas out of the air conditioning system.
3. Wait for a few hours, depending on the size of the refrigerating system and monitor the pressure rise.
If the pressure rises until 1 bar absolute, then there is leak.
If the pressure rises, but it is lower than 1 bar absolute, then moisture is present.
Next, remove the moisture, or repair, and redo the refrigerant leak testing, starting from “Step 1: Pressure test”.
2
2
3
Vacuum pump
Handle
(Low/Gas)
pressure gauge
(High/Liquid) pressure gauge
An example illustrations of setup for
refrigerant leak detection.