Specifications
7
Operation, cooling and hydraulic diagram, heat pump unit YLHA PLUS 5 to 15
Cooling cycle
The 4-way valve is activated. Heat exchange takes place
between the heat transfer liquid (water or glycol water) and
the refrigerant in the plate heat exchanger. Water is cooled,
and refrigerant is evaporated and reheated. Then the Scroll
type compressor condenses the refrigerant (gas) until the
condensing pressure is reached, and the refrigerant goes to
the air cooled condensing unit. In the air cooled condensing
unit, heat is exchanged between the air and the refrigerant.
The air is heated and evacuated from the chiller (heat rejec-
tion). The refrigerant is condensed and sub-cooled. Then the
refrigerant (liquid) goes on to the expansion valve, where it
is expanded until the evaporating pressure is reached, at
which time it goes to the plate heat exchanger to start a new
cooling cycle.
Heating cycle
The cooling mode is inverted. The 4-way valve is not activated.
The condensing unit becomes the evaporating unit, and the
evaporating unit becomes the condensing unit. The water in
the plate heat exchanger is heated.
SAFETY/CONTROL DEVICES
A High pressure switch
B Low pressure switch
C Pressure transducer port
E Condensing unit temp. sensor
(fan speed, defrost and display settings)
F Water outlet temperature sensor
(antifreeze and display)
G Water intake temperature sensor
(Setting and display)
COMPONENTS
1 Compressor
2 Air cooled condenser
3 Filter-dryer
4 Expansion valve
5 Water pump
6 Plate heat exchanger
7 Automatic air bleed
8 Expansion vessel
9 Four-way valve
10 Liquid receiver
11 Drain connection
12 Water filter (not inside the unit)
13 Relief valve
14 Flow switch
Pipe connection with Schrader valve
For units with hydro kit only