Gree VERSATI SERIES, Service Manual

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74
Air to Water Heat Pump
Service Manual- Versati Series
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Example 2: The indoor unit is installed on the highest spot of the water system and the total water volume is
350L.
As the volume of water system is higher than 280L, it is necessary to adjust the pressure of the expansion
vessel be lower.
The formula of calculating pressure
P
g
=(H/10+0.3)=(0/10+0.3)=0.3 Bar
The maximum volume of the water system is about 410L. As the actual volume of the water system is 350L,
the expansion vessel meets the installing requirement.
Adjust the pre-set pressure of the expansion vessel from 1.0Bar to 0.3Bar.
Selection of expansion valve
Formula:
1
2
v=
1
1
1
c e
p
p
˜
v
--- Volume of expansion vessel
c
--- Total water volume
1
p
--- Pre-set pressure of expansion vessel
2
p
-- The highest pressure during running of the system (that is the action pressure of safety valve.)
e
--- The expansion factor of water (the difference between the expansion factor of the original water
temperature and that of highest water temperature.)
Water expansion factor in different temperature
Temperature( ) Expansion factor
e
0 0.00013
4 0
10 0.00027
20 0.00177
30 0.00435
40 0.00782
45 0.0099
50 0.0121
55 0.0145
60 0.0171
65 0.0198
70 0.0227
75 0.0258
80 0.029
85 0.0324
90 0.0359
95 0.0396
100 0.0434
(3) Filling of Refrigerant
Before shipped out from manufacturer, the outdoor unit has been filled with refrigerant. Additional
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Check the liquid valve and the gas valve of the outdoor unit. The valves shall be completely shut off.
Connect a vacuum pump to the liquid valve and the gas valve of the outdoor unit to remove air from the
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Pressure meter
“HI”knob
Vacuum pump
“Lo”knob
Liquid valve
Gas valve
Connection pipe