Water Volume And Expansion Vessel Pressure; The Method Of Calculating The Charging Pressure Of Expansion Vessel - Gree Versati III GRS-CQ4.0PdG/NhH2-E Owner's Manual

Air-to-water Heat Pump All in One Versati

7.6 Water volume and expansion vessel pressure

Notes
(a) The expansion vessel is 10 liter and 1bar pre-pressurized;
(b) Total water volume of 280 liter is default; if total water is changed because of installation condition, the pre-
pressure should be adjusted to secure proper operation. If the indoor unit is located at the highest position,
adjustment is not required;
(c) Minimum total water volume is 20 liter;
(d) To adjust pre-pressure, use nitrogen gas by certificated installer.

7.7 The method of calculating the charging pressure of expansion vessel

The method of calculating the charging pressure of expansion vessel needed to be adjusted is as follows.
During installation, if the volume of water system has changed, please check if the pre-set pressure of the
expansion vessel needs to be adjusted according to the following formula:
Pg=(H/10+0.3) Bar (H ---the difference between installing location of indoor unit and the highest spot of
water system.)
Ensure that the volume of water system is lower than the maximum volume required in the above figure. If it
exceeds the range, the expansion vessel does not meet the installing requirement.
Installation height
difference
＜ 7m
＞ 7m
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 indoor unit is installed 5m below the outdoor unit and the total volume of the water system is
100L.Referring to the above figure, it is not necessary to adjust the pressure of the expansion vessel.
＜ 280L
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 figure)
22
Water volume
＞ 280L
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 figure)
The expansion vessel is too small and
adjustment is not available.
SPLIT TYPE