Water
inlet
Water
outlet
Refrigerant
outlet
Refrigerant
inlet
Mechanical Specifications
5--3
Liebert HPC--- S 006--- 022--- PD--- 273571--- 01.03.2012
All exchangers are optimized for the refrigerant R410A and are
complete with an inner device (distributor) evenly distributing
the refrigerant gas on each channel.
They are externally insulated against condensate with closed
cell elastomer.
The evaporators are connected with lines equipped with drain-
age and vent connections.
The evaporators are protected against freezing by a paddle---
type flow switch and a standard antifreeze sensor directly man-
aged by the microprocessor.
As an option, thermostatically controlled heaters are applied to
prevent freezing with outdoor temperatures below 0
°C without
primary flow.
Tab. 5a --- Working Limits
Design Temp. Design Pressure Test Pressure
Min. / Max. Refrigerant Water Refrigerant Water
--- 196 / +150 _C 45.0 bar 45.0 bar 74.0 bar 74.0 bar
Condensers
The condensing coils design for R410A refrigerant are made of copper tubes and aluminium fins for free-
cooling version and aluminium tubes and aluminium fins for chiller version and are mounted in vertical
configuration. Copper tubes in staggered rows are mechanically expanded in order to have the best con-
tact with fins. The aluminium fins are manufactured with a special high efficiency rusticate surface that
increases the thermal exchange.
The condensing coils are tested at a pressure of 45 bar.
Hydraulic Circuit
The hydraulic circuit --- with max. working pressure 6 bar --- is made up of carbon steel pipes connected
with threaded fitti ngs and couplings; gaskets are made of EPDM.
This arrangement permits compensation for thermal expansion, reduces noise and vibration propagat-
ing through hydraulic pipelines and facilitates ease of maintenance. The anti---co ndensate insulation of
the hydraulic circuit is by closed cell synthetic elastomer.
The flow switch is a compulsory protection device for the unit fitted as standard on all units versions with
or without recirculation pumps.
Expansion Vessel and Safety Valve
These accessories are directly installed on the unit hydraulic circuit as standard. The expansion vessel
(charged at 1.5 bar, max. operating pressure 10 bar) has an 8 litres volume, the safety valve is set at 3.5
bar when pumps are fitted, in other cases it is set at 6 bar. Their installation positions are indicated in the
hydraulic circuit scheme. It is recommended that the total expansion vessel capacity required be always
checked, depending on the unit volume, the circuit volume, the glycol percentage in the mixture and the
expected maximum temperature variation of the mixture.
Freecooling Execution
L i e b e r t H P C --- S 0 0 6 --- 0 2 2 models in the ”Freecooling execution” are designed with an integrated free-
cooling system consisting of:
D cooling coils with copper tubes and aluminium fins, mounted in vertical configuration;
D vent and drainage valves on the freecooling coils;
D low pressure drop three ---way valve with modulating servo---control.
All the freecooling functions are managed by the microprocessor control in three operating modes, ac-
cording to ambient conditions and thermal load:
D direct expansion with compressors operation only; 100% water flow through the evaporator;
D direct expansion and Freecooling; 100% water flow first through the freecooling coils and then
through the evaporator, with partial compressor operation;
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