Requirements And Recommendations For Hydraulic Circuit; Requirements For Anti-Freezing; Minimum Required Water Volume; Minimum Required Water Flow - Hisense Hi-Therma-Serie Bedienungsanleitung

9.2 REQUIREMENTS AND RECOMMENDATIONS
for HYDRAULIC CIRCUIT

9.2.1 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 "10.5 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.
● 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.

9.2.2 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 044/060(2.0HP/2.5HP)
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.
080(3.0HP)
30L 45L
044/060
080(3.0HP)
(2.0/2.5HP)
61 L 61 L
99 L 99 L
158 L 158 L
198 L 198 L
SPACE HEATING/COOLING AND DHW
● 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.

9.2.3 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)
9.2.4 Additional Information about hydraulic
circuit
● An additional special water filter is highly recommended
to be installed on the space heating (field installation),
in order to remove possible particles remaining from
brazing which cannot be removed by the field supplied
shut-off valve with filter.
● Put insulation on the pipes in order to avoid heat losses.
● Whenever possible, sluice valves should be installed for
water piping, in order to minimize flow resistance and to
maintain sufficient water flow.
● Ensure that the installation complies with applicable
legislation in terms of piping connection and materials,
hygienic measures, testing and the possible required
use of some specific components like thermostatic
mixing valves.
● The maximum water pressure is 3 bar (nominal opening
pressure of the safety valve). Provide adequate
reduction pressure device in the water circuit to ensure
that the maximum pressure is NOT exceeded.
● The water pressure can be read on master controller,
detected by the water pressure sensor located at inlet of
plate heat exchanger. If water pressure exceeded 3 bar,
the water pressure displayed on master controller would
flash.
● Ensure that the drain pipes connected to the safety
valve and to the air purge valve are properly driven to
avoid water being in contact with unit components.
● Make sure that all field supplied components installed
in the piping circuit can withstand the water pressure
and the water temperature range in which the unit can
operate. The units are conceived for exclusive use in a
closed water circulation.
● The internal air pressure of the expansion vessel will
be adapted to the water volume of the final installation
(factory supplied with 1 bar of internal air pressure).
● Drain taps must be provided at all low points of the
installation to permit complete drainage of the circuit
during servicing.
● The maximum piping length depends on the maximum
pressure availability in the water outlet pipe. Please
check the pump curves.
17
Min. water flow(L/min)
8.3
10.0