HWA1-A & HWA1-H
Air/Water chillers and heat pumps with axial fans
14
7.5.2
Plant circuit loading
WARNING: Verify all the charging/topping up operations.
WARNING: Before beginning the charging/topping up operation of the plant circuit, disconnect the unit from the
electric power supply.
WARNING: The charging/topping up of the plant circuit must always be done under controlled conditions of pressure
(max 1 bar). Make sure that you have installed on the line of charging/topping up a pressure reducer and a relief valve.
WARNING: The water on the charging/topping up pipe must be suitably pre-filtered from any impurities and
suspended particles. Make sure that you have installed a cartridge filter removable.
WARNING: Before beginning the charging /topping up operation, unscrew the plugs of the air vent valve. Tighten the
plugs after finishing the operation of charging/topping up of the plant circuit system.
7.5.3
Plant drainage system
In the case when it is necessary to unload the plant, close at first the inlet and outlet manual gate valves (not supplied) and then
remove the pipes that are disposed externally on the water inlet and on the water outlet in order to spill away the liquid contained
in the unit (in order to make easy the operation, it is recommended to install externally two draining valves, on the water inlet and
on the water outlet, between the unit and the manual gate valves).
7.6
REFRIGERANT CIRCUITS
7.6.1
Refrigerant circuit
of HWA1-A 0140 – 0147 units
C
Compressor
DT
Compressor outlet temperature
EV
Expansion valve
FD
Unidirectional filter drier
SG
Liquid indicator
HP
High pressure transducer
IN
Water inlet temperature sensor
LP
Low pressure transducer
LR
Liquid receiver
LS
Liquid separator
M
Axial fan motor
OUT
Water outlet temperature sensor
Pr
High pressure flow switch
PV
Pressure intake
SE
Outdoor air temperature sensor
ST
Compressor inlet temp.
SV
Solenoide valve
1
During the operations of charging/topping up, the plugs of the air vent
valves must be partially unscrewed to allow air to flow freely out of the
valves.
(1)
Plug of the air vent valve
You can use the service valve, when it is necessary to refill the plant or
adapt the concentration of glycol. Unscrew the plug (cap) of the service
valve and connect to the hose a pipe of 14 mm (inner diameter)
connected to the water network, and then fill the system by
unscrewing the knurled nut. When the operation is concluded,
retighten the knurled nut and screw on the plug. In any case, we
recommend you to use for the water loading of the plant an external
tap whose arrangement is by the installer.
Cap with gasket
Knurled nut
