Requirements And Recommendations For Hydraulic Circuit; Requirements For Anti-Freezing; Minimum Required Water Volume; Minimum Required Water Flow - Hisense Hi-Therma Series Installation & Maintenance Manual

SPACE HEATING AND DHW
?
N O T E
The discharge pipe should always be open to the atmosphere, free
of frost and in continuous slope to the down side in case that water
leakage exists.
In case of a recirculation circuit for the DHW circuit, the following
elements are required:
Nature No.
1
Piping connections
2
3
Field supplied 4
5
A Recirculation water pump (field supplied): This water
•
pump (3) will help to correctly recirculate the hot water to the
DHW inlet.
• A Water check valve (field supplied):
This accessory (3) is connected after the recirculation water
pump (4) in order to ensure the nonreturn of water.
• Two Shut-off valves (field supplied) (5):
One before the recirculation water pump (4) and other after
the water check valve accessory (3).
!
C A U T I O N
The water check valve shall be confirmed installed in the correct
direction. Otherwise, serious damages may occur in the DHW tank.
8.2 REQUIREMENTS and RECOMMEN-
DATIONS for HYDRAULIC CIRCUIT

8.2.1 Requirements for anti-freezing

• When the unit is stopped during shut-off periods and the
ambient temperature is very low, the water inside the pipes
and the circulating pump may freeze, thus damaging the
pipes and the water pump. In these cases, the installer shall
ensure that the water temperature inside the pipes does not
fall below the freezing point. In order to prevent this, the unit
has a self-protection mechanism which should be activated
(refer to "9.5 SETTING OF DIP SWITCHES ON PCB1").
•
Even if the unit is stopped, the water pump may run under
some circumstances, i.e, when the anti-freezing function is
triggered.
• Keep the unit power on and water system unblocked to
prevent water freezing, otherwise an alarm may occur.
• If the water system is blocked, an alarm of water flow will
occur to stop the whole system.
Supplementary water inlet of DHW tank
DHW tank outlet
Water check valve
Water pump
Shut-off valve
•
If machine is stopped for a long period of time in winter, drain
out water in circuit and water pipes to prevent freezing.
• The anti-freezing protection is effective better with Auxiliary
electric heater connected. It is advisable to install the
Auxiliary electric heater for those models in which these are
not supplied but optional.
However, in case of a power failure or unit failure, these
•
functions cannot guarantee protection.

8.2.2 Minimum required water volume

The following part shows the minimum water volume in the
system for product protection (anti-hunting) and temperature
drop at defrosting.
•
Minimum required water volume in each single water circuit of DHW /
SWP for product protection (anti-hunting).
Water volume in each single water circuit of DHW / SWP need be
greater than 20L.
•
Minimum required water volume in single water circuit of space
cooling for product protection (anti-hunting).
The following table shows the minimum water volume needed in
single water circuit of space cooling.
Model
Minimum required
water volume
•
Minimum required water volume during defrosting.
The following table shows the minimum water volume needed in
single water circuit of space heating in case of safe defrosting.
Lowest possible operation
water temperature in
single water circuit of
space heating
≥25°C
20-25°C
15-20°C
10-15°C
•
The values shown on the table are based on theoretical installation
conditions. And the value can be different depending on each
specific installation.
•
To calculate minimum water volume the internal water volume of the
unit is NOT included.
•
Consult with local technical engineer under the special occasions
where operation water temperature in single water circuit of space
heating is lower than 20°C.

8.2.3 Minimum required water flow

Check that the water pump of the water circuit works within the
pump operating range and that the water flow is over the unit
minimum value.
Model
044(2.0HP)
060(2.5HP)/080(3.0HP)
14
044/060(2.0HP/2.5HP) 080(3.0HP)
30L
044/060
080(3.0HP)
(2.0/2.5HP)
61 L
99 L
158 L
198 L
min. water flow(L/min)
8.3
10.0
45L
61 L
99 L
158 L
198 L