Checking For Leakage - LG MULTI F A2UW16GFA0 Engineering Product Data Book

2. Guideline for each installation process

2.6.3 Checking for leakage

[Check 1] (Where pressure falls while carrying out Steps 1 to 3 described on previous page)
▶ Check by measure gage......Gas detector.
▶ Check by ear......Listen for the sound of a major leakage.
▶ Check by hand......Check for leak by feeling around jointed sections with hand.
▶ Bubble check ......Bubbles will reveal the presence of a leakage.
[Check 2] (When searching for a minor leak or when there has been a fall in pressure while the system has been fully pres-
surized but the source of the leak cannot be traced.)
① Release the nitrogen until the pressure reaches 0.3MPa.
② Increase pressure to 1.5MPa using gaseous refrigerant(R410).
③ Search for the source of the leakage using a leackage detector such as a halide torch or a propane or electrronic detector.
④ If the source of the leakage still cannot be traced then repressurize with nitrogen up to 3.8MPa and check again.
(The pressure must not be increased to more than 3.8MPa.)
(System sample)
Gas Pipe
Nitrogen gas
Important points
Where the lengths of piping involved are particularly long then the air tight test should be carried out block by block.
- Indoor side
- Indoor side + vertical pipes
- Indoor side + vertical pipes + outdoor side
CAUTION
Soap water method
1. Remove the caps from the 2-way and 3-way valves.
2. Remove the service-port cap from the 3-way valve.
3. To open the 2-way valve turn the valve stem counterclock-
wise approximately 90°, wait for about 2~3 sec, and close it.
4. Apply a soap water or a liquid neutral detergent on the indoor
unit connection or outdoor unit connections by a soft brush to
check for leakage of the connecting points of the piping.
5. If bubbles appear then those points have leakage.
Liquid Pipe
(R410A gas)
Gauge
Vacuum pump
2-way valve
(Open)
3-way valve
(Close)
Hexagonal wrench
Heat pump
Do not open the
service valve during
the airtight test.
Gas side
Cap
_ 28
60Hz/R410A