Measures To Take In The Case Of Gas Leaks; Gas Shortage - Daikin VRV Plus Series General Information Manual

Si33-003.book Page 183 Monday, June 25, 2001 9:06 AM
SiE33-003

9. Measures to Take in the Case of Gas Leaks

9.1

Gas Shortage

Problems caused by insufficient gas are almost the same as those for R22 air conditioners. They include
capacity decrease, compressor overheating and frost accumulation on cooler.
(Guideline for judging gas shortage)
Refrigerant
R22
R-407C
1 Intermediate pressure between saturation liquid pressure and saturation gas pressure at 50˚C
2 Intermediate pressure between saturation liquid pressure and saturation gas pressure at 0˚C
(Composition change and capacity decrease caused by gas leaks)
New Refrigerant R-407C
The following shows the relationship between pressure and temperature for R22 and R-407C. Use the
data as the guideline when checking pressure levels.
Condensation pressure
MPa (kgf/cm²)
1.84 (18.8)
2.00 (20.5)
temperature (gauge pressure)
temperature (gauge pressure)
The following composition change occurs when the refrigerant gas leaks, particularly with R-407C,
since R-407C is a non-azeotropic mixture.
Due to the above composition change, the percentage of R134a increases, thus causing a capacity
drop. The degree of capacity drop that a gas shortage causes is nearly the same in R22 air conditioners
and R-407C air conditioners.

Measures to Take in the Case of Gas Leaks

Evaporation pressure
1 MPa(kgf/cm²) 2
0.48 (4.92)
0.51 (5.16)
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