Gree GRS-CQ6.0Pd/Na-K Service Manual page 83

AIR-TO-WATER HEAT PUMP
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;
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:
=
P ( H /10 0.3)
g
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
＜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 height difference is considered 0m；
The minimum volume of the water system is 20 L.
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
+
Bar （H ---the difference between installing location of
１
＜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)
INSTALLATION
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.
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