Rxyq8, 10, 12M ( Products After January, 2004) - Daikin VRV II RXYQ5MY1B Service Manual

Refrigerant Circuit
1.2 RXYQ8, 10, 12M (
No. in
refrigerant
Symbol
system
diagram
A M1C Inverter compressor (INV)
Standard compressor 1
B M2C
(STD1)
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 (Oil
H Y2S
equalization: SVO)
Solenoid valve (Receiver gas
J Y3S
discharging: SVG)
Solenoid valve (Non-operating
L Y4S
unit liquid pipe closing: SVSL)
M Y5S 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)
S — Fusible plug
Pressure regulating valve 2
U —
(Liquid pipe to receiver)
Pressure regulating valve 3
V — (Equalizing pipe to discharge
pipe)
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 (Heat exchanger
6 R4T
deicer: Tb)
Thermistor (Subcooling heat
7 R5T
exchanger gas pipe: Tsh)
Thermistor (Receiver outlet
8 R6T
liquid pipe: Tl)
Thermistor (Oil equalizing
9 R7T
pipe: To)
Note: Please refer the refrigerant circuit for products before December, 2003 to service manual
Si39-302.
52
*
Products after January, 2004)
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.
RXYQ8, 10, 12M: 29 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 for oil equalizing among outdoor units in multiple-outdoor-unit system.
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 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.
Used to detect equalizing pipe temperature, opening/closing of the equalizing pipe
stop valve, and others.
Major Function
SiE39-404
Refirgerant Circuit