Gree GRS-CQ10Pd/NhG-M - Selection of Expansion Vessel

Air-to-water Heat Pump
23
MONOBLOC TYPE
exceeds the range, the expansion vessel does not meet the installing requirement.
For 4/6/8 units
Installation height
1
difference
Water volume
<44L >44L
<12 m Adjustment is not necessary
1. Pre-set pressure needs to be adjusted
according to the above formula.
2. Check if the water volume is lower
than the maximum water volume. (with
help of the above gure)
﹥
12 m
1. Pre-set pressure needs to be adjusted
according to the above formula.
2. Check if the water volume is lower than the
maximum water volume. (with help of the above
gure)
The expansion vessel is too small and
adjustment is not available.
For 10/12/14/16 units
Installation height
1
difference
Water volume
<66L >66L
<12 m Adjustment is not necessary
1. Pre-set pressure needs to be adjusted
according to the above formula.
2. Check if the water volume is lower
than the maximum water volume. (with
help of the above gure)
﹥
12 m
1. Pre-set pressure needs to be adjusted
according to the above formula.
2. Check if the water volume is lower than the
maximum water volume. (with help of the above
gure)
The expansion vessel is too small and
adjustment is not available.
Note
(a) Installation height difference: the difference between installing location of indoor unit and the highest spot of
water system; if the indoor unit is located at the highest point of the installation,the installation height difference
is considered 0m.
Example 1: The 16kW unit is installed 5m below the highest spot of water system and the total volume of the
water system is 60L.
Referring to the above gure, it is not necessary to adjust the pressure of the expansion vessel.
Example 2: The unit is installed on the highest spot of the water system and the total water volume is 100L.
(b) As the volume of water system is higher than 75L, it is necessary to adjust the pressure of the expansion
vessel be lower.
(c) The formula of calculating pressure
(d) Bar
(e) The maximum volume of the water system is about 410L. As the actual volume of the water system is 118L,
the expansion vessel meets the installing requirement.
(f) Adjust the pre-set pressure of the expansion vessel from 1.5Bar to 0.3Bar.
7.4 Selection of expansion vessel
Formula:
V--- Volume of expansion vessel
C--- Total water volume
P
1
--- Pre-set pressure of expansion vessel
P
2
-- The highest pressure during running of the system (that is the action pressure of safety valve.)