Daikin VRV - Page 44

Other Functional Operations Si30-408
40 Basic Information
K
Solenoid valve (Non-
operating unit gas
discharging)
SVSG (Y5S)
On the outdoor unit multi system, used to prevent the
refrigerant from accumulating in outdoor units in stop
mode.
L
Solenoid valve (Non-
operating unit liquid pipe
closing)
SVSL (Y6S)
On the outdoor unit multi system, used to prevent the
refrigerant from accumulating in outdoor units in stop
mode.
M Four way valve — (Y7S)
Used to switch the unit to cooling operation or heating
operation.
P
High-pressure switch (For
INV compressor)
— (S1PH)
In order to avoid the increase in high pressure while in
malfunction, these switches are actuated at a
pressure of 3.8MPa or more to stop the unit.
(2.7 MPa for R22 unit)
Components
of outdoor unit
Q
High-pressure switch (For
STD compressor 1)
— (S2PH)
R
High-pressure switch (For
STD compressor 2)
— (S3PH)
S Fusible plug — —
In order to avoid increase in pressure at abnormal
hating due to fire, the fusible part melts at a
temperature of 70 to 75°C, thus relieving pressure into
atmosphere.
T
Pressure regulating valve 1
(Receiver to Discharge
pipe)
——
In order to prevent damage to functional parts due to
increase in pressure in transport or storage, these
valves open at pressure of 2 to 2.7MPa, thus avoiding
the increase in pressure.
(1.5 ~ 2.0 MPa for R22 unit)
U
Pressure regulating valve 2
(Liquid pipe to Receiver)
——
V
Pressure regulating valve 3
(Oil equalizer pipe to
Discharge pipe)
——
Components
of indoor unit
X Indoor unit heat exchanger — —
This heat exchanger serves as an evaporator while in
cooling operation or a condenser while in heating
operation (air cooling).
Y
Indoor unit electronic
expansion valve
— (Y1E)
Used to control the superheated degree (SH = Tg – TI)
in cooling operation or subcooled degree (SC = Tc –
TI) in heating operation. This valve slightly opens (i.e.,
240 pls) with thermostat OFF (compressor ON) in
heating operation, thus preventing the accumulation
of oil.
No. Part name Symbol
(Electrical
symbol)
Function