Rxyq14Ma, 16Ma - Daikin RXYQ5-48MAY1 Service Manual

Refrigerant Circuit
1.3

RXYQ14MA, 16MA

No. in
refrigerant
Symbol
system
diagram
A M1C Inverter compressor (INV)
Standard compressor 1
B M2C
(STD1)
Standard compressor 1
C M3C
(STD2)
D M1F Inverter fan
Electronic expansion valve
E Y1E
(Main: EV1)
Electronic expansion valve
F Y2E
(Subcool: EV2)
G Y1S Solenoid valve (Hot gas: SVP) Used to prevent the low pressure from transient falling.
Solenoid valve (Receiver gas
J Y2S
discharging: SVG)
Solenoid valve (Non-operating
L Y3S
unit liquid pipe closing: SVSL)
M Y4S 4-way valve
N S1NPH High pressure sensor
O S1NPL Low pressure sensor
HP pressure switch (For INV
P S1PH
compressor)
HP pressure switch (For STD
Q S2PH
compressor 2)
HP pressure switch (For STD
R S3PH
compressor 1)
S — Fusible plug
Pressure regulating valve 2
U —
(Liquid pipe to receiver)
V — Piping heat exchanger
W — Capillary tube
X — Capillary tube
Y — Capillary tube
Z — Capillary tube
1 R1T Thermistor (Outdoor air: Ta)
2 R2T Thermistor (Suction pipe: Ts)
Thermistor (INV discharge
3 R31T
pipe: Tdi)
Thermistor (STD1 discharge
4 R32T
pipe: Tds1)
Thermistor (STD2 discharge
5 R33T
pipe: Tds2)
Thermistor (Heat exchanger
6 R4T
deicer: Tb)
Thermistor (Subcooling heat
7 R5T
exchanger gas pipe: Tsh)
Thermistor (Receiver outlet
8 R6T
liquid pipe: Tl)
54
Name
Inverter compressor is operated on frequencies between 52 Hz and 210 Hz by using
the inverter, while Standard compressor is operated with commercial power supply
only. The number of operating steps is as follows when Inverter compressor is
operated in combination with Standard compressor.
RXYQ14A, 16MA: 35 steps
Since the system is of air heat exchanging type, the fan is operated at 8-step rotation
speed by using the inverter.
While in heating operation, PI control is applied to keep the outlet superheated degree
of air heat exchanger constant.
PI control is applied to keep the outlet superheated degree of subcooling heat
exchanger constant.
Used to collect refrigerant to receiver.
Used to prevent the accumulation of refrigerant in non-operating outdoor units in the
case of multi-outdoor unit system.
Used to switch the operation mode between cooling and heating.
Used to detect high pressure.
Used to detect low pressure.
In order to prevent the increase of high pressure when a malfunction occurs, this
switch is activated at high pressure of 3.8 MPA or more to stop the compressor
operation.
In order to prevent the increase of pressure when abnormal heating is caused by fire
or others, the fusible part of the plug is molten at a temperature of 70 to 75°C to
release the pressure into the atmosphere.
This valve opens at a pressure of 2 to 2.7 MPa for prevention of pressure increase,
thus resulting in no damage of functional parts due to the increase of pressure in
transportation or storage.
Used to heat the gas refrigerant from the liquid receiver.
Used to return the refrigerating oil separated through the oil separator to the INV
compressor.
Used to return the refrigerating oil separated through the oil separator to the STD1
compressor.
Used to return the refrigerating oil separated through the oil separator to the STD2
compressor.
Used to add the refrigerant flow capacity to Y1E
Used to detect outdoor temperature, correct discharge pipe temperature, and others.
Used to detect suction pipe temperature, keep the suction superheated degree
constant in heating operation, and others.
Used to detect discharge pipe temperature, make the temperature protection control of
compressor, and others.
Used to detect liquid pipe temperature of air heat exchanger, determine defrosting
operation, and others.
Used to detect gas pipe temperature on the evaporation side of subcooling heat
exchanger, keep the superheated degree at the outlet of subcooling heat exchanger
constant, and others.
Used to detect receiver outlet liquid pipe temperature, prevent the drift between
outdoor units while in heating operation in the case of multiple-outdoor-unit system,
and others.
Major Function
Si39-407
Refirgerant Circuit