Water Volume And Expansion Vessel Pressure; The Method Of Calculating The Charging Pressure Of Expansion Vessel - Gree GRS-CQ4.0Pd/NhG3-E Owner's Manual

Air-to-water Heat Pump

7.3 Water volume and expansion vessel pressure

Notes
(a) The expansion vessel is 2 liters and 1.5bar pre-pressurized for 4/6kW units; 3 liters and 1.5bar per-
pressurized for 8/10/12/14/16kW units;
(b) Total water volume of 44 liters is default for 4/6kW units and 66 liters for 8/10/12/14/16kW unit; if total water
is changed because of installation condition, the pre-pressure should be adjusted to secure proper operation. If
the unit is located at the highest position, adjustment is not required;
(c) Minimum total water volume is 20 liters;
(d) To adjust pre-pressure, use nitrogen gas by certificated installer.

7.4 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:
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.
Bar (H ---the difference between installing location of indoor unit and the highest spot of
8/10/12/14/16kW
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MONOBLOC TYPE