Gree GMV6 DC Inverter VRF Units Service Manual
204
Chapter 4 Maintenance
During the maintenance of a modular unit, all the outside units must be powered on and off
concurrently. Avoid doing so to only some of the outdoor units.
1 Precautions for Refrigerant Leakage
(1) AC project designers and installers shall obey the local laws and regulations on the safety
requirement of the usage and leakage of refrigerant.
(2) The multi VRF unit adopts R410A refrigerant. When installing in the space with people, the refrigerant
amount shall not exceed the max.allowable concentration. Otherwise, suffocation will occur. For
example, the max.allowable concentration for refrigerant of European safety standard and regulation
is 0.44kg/m
3
.
Max. refrigerant charge(kg)= Room volume(m
3
)× max. allowable concentration(kg/m
3
)
Refrigerant charge(kg)= Adding quantity of refrigerant(kg)+ ∑ex-factory charge of ODU(kg)
Refrigerant charge ≤ Max. refrigerant charge
(3) When refrigerant charge has exceeded the max.refrigerant charge, re-design the refrigeration
system and divide the refrigeration system to several refrigeration systems of small volume, or add
corresponding ventilation measures and alarms.
Since the concentration of refrigerant is greater than that of air, pay attention to the spaces where
the refrigerant may residue, for example, the basement.
2 Refrigerant Charging
Total refrigerant charging amount R= Pipeline charging amount A + Σ charging amount B of every
module.
2.1 Pipeline charging amount:
Pipeline charging amount A= Σ Liquid pipe length × refrigerant charging amount of every 1m liquid
pipe.
Diameter of
liquid pipe
(mm(inch
)
)
Φ28.6
(1-1/8)
Φ25.4
(1)
Φ22.2
(7/8)
Φ19.05
(3/4)
Φ15.9
(5/8)
Φ12.7
(1/2)
Φ9.52
(3/8)
Φ6.35
(1/4)