Water Volume And Expansion Vessel Pressure; The Method Of Calculating The Charging Pressure Of Expansion Vessel - Gree GRS-CQ16Pd/NaB-K Owner's Manual

② If the noise of the pump is not acceptable, we recommended change the default speed
to medium speed, but to secure enough flow rate, do not set water speed as "Min", it can lead
unexpected flow rate error "EC";

9.7 Water volume and expansion vessel pressure

Note:
① Expansion vessel is included which 10 liter and 1bar pre-pressure.
② 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;
③ Minimum total water volume is 20 liter;
④ To adjust pre-pressure, use nitrogen gas by certificated installer.

9.8 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:
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.
1
Installation height
difference
<7 m
<7 m
1
Note: 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
2.5
2.0
1.5
1.0
0.5
0.0
0 50 100
Maximum total water volume(liter)
<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)
150 200 250 300 350
Water volume
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.
16
Air-to-water Heat Pump
400
>280L