MTA HAST 080 N - Liquid Receiver; Cycle Reversal Valve

MAINTENANCE AND OPERATING MANUAL
Description
HAS T 070÷140
37
ENGLISH
EN
The data in this manual are not binding and they can be modified by the manufacturer without notice. Reproduction of this manual is strictly prohibited.
3.2.6 Liquid receiver
NOTE
SUBCOOLING: The liquid is not subcooled at the receiver outlet because of the constant presence of a small quantity of gas.
ATTENTION
LIQUID SIGHT GLASS DOWNLINE OF THE FILTER: The liquid sight glass will always show air bubbles in the liquid
flow; do not use the sight glass as a reference for refrigerant charging risk of overfilling the circuit.
3.2.7 Cycle reversal valve
The 4-way cycle reversal valve is utilised to invert the direction of flow of refrigerant fluid in order to heat or cool the
process water. This valve makes it possible to perform defrost cycles during HEAT-PUMP mode operation. The four valve
pipes are brazed to the high-low pressure sides of the compressors and exchangers (condenser and evaporator) making up the
refrigerant circuit. The spool of the main valve is shifted by a pilot solenoid valve.
4-way valve spool movement is controlled via software.
The operating principle is illustrated in the following diagrams.
The liquid receiver is installed to hold the higher volume of refrigerant present in the liquid phase when the unit is
operating in “HEAT-PUMP (WINTER)” mode. The plate evaporator (with respect to the condensing coils) offers reduced
volume when functioning as a condenser in heat pump mode. The liquid receiver is equipped with a level sight glass,
although the reading is reliable only when the unit is operating in chiller mode.
IN
UPPER AREA:
presence of gas only
level in
HEAT-PUMP mode
level in
CHILLER mode
LEVEL
SIGHT GLASS
FILTER
TO THE
THERMOSTATIC
LIQUID SIGHT-GLASS
EXPANSION VALVE