Daikin R407C PLUS - Page 45

Refrigerant System Diagram Si33-105
34 Function R407C PLUS Series Heat Recovery System
RSEYP24~30KJY1
No. Name Code Function Remarks
A Inverter compressor M1C Combination of a compressor (inverter compressor) capable of
operating at 29-95 Hz with inverter drive and compressors
(constant-speed compressors) operable only on commercial
power supply achieves multi step control.
B Constant-speed
compressor 1
M2C
C Constant-speed
compressor 2
M3C
D 4 way valve Y1R Change the refrigerant flow to the main unit heat exchanger 1 and
2, to switch the condenser↔evaporator.
E 4 way valve Y2R Change the refrigerant flow to the sub-unit heat exchanger to
switch the condenser↔evaporator.
F 4 way valve Y3R Change the refrigerant flow to the outdoor main unit discharge line
to switch the high temperature high pressure gas↔low
temperature & low pressure gas.
J Electronic expansion valve Y1E (For main unit heat exchangers 1)
Provides PI control during evaporator to maintain constant
superheated degree (SH).
Main unit
’
s
left side
exchanger
K Electronic expansion valve Y2E (For main unit heat exchangers 2)
Provides PI control during evaporator to maintain constant
superheated degree (SH).
Main unit
’
s
right side
heat
exchanger
L Electronic expansion valve Y3E (For sub unit’s heat exchanger)
Provides PI control during heating operation to maintain constant
superheated degree (SH).
M Solenoid valve Y1S (For auxiliary condensers)
Use for heat exchanger capacity control during simultaneous
cooling / heating operation.
N Solenoid valve Y2S (For hot gas bypass and pressure equalization)
Bypasses hot gas during transitional operation such as defrosting
operation to prevent sudden decrease of low pressure. Also
equalizes pressure to reduce startup load.
O Solenoid valve Y3S (For inverter unit liquid injection)
Provides liquid injection to prevent overheating operation.
P Solenoid valve Y4S (For receivers)
Use for pump-down refrigerant to receiver.
Q Solenoid valve Y5S (For liquid pressure control)
Use for maintaining liquid pressure during heat exchanger capacity
control.
R Solenoid valve Y6S (For constant-speed comp. 1 liquid injection)
Provides liquid injection to prevent overheating operation.
S Solenoid valve Y7S (For constant-speed comp. 2 liquid injection)
Provides liquid injection to prevent overheating operation.
T High pressure sensor SENPH Heating operation: Provides PI control for compressors and heat
exchanger by detecting high pressure.
Cooling operation: Controls compressors to ensure sufficient high
pressure when outside temperature is low.
U Low pressure sensor SENPL Cooling operation: Provides PI control for compressors and heat
exchanger by detecting low pressure.
Heating operation: Controls motorized valves to maintain constant
evaporator superheated degree.
V High pressure switch Q1PH Opens at set pressure of 2.94 MPa to stop operation.
W High pressure switch Q2PH
X High pressure switch Q3PH
Y Pressure regulating valve Pressure relief valve to protect liquid sealing in receiver piping
during transportation or storing.
It opens at 2.65 MPa.
Z Fusible plug Plug head melt at 70~75°C around receiver and high pressure and
high temperature refrigerant is relived.