Daikin VRV, Руководство по обслуживанию

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Si30-408 Other Functional Operations
Basic Information 37
„ Explanation on Component Function
* Electric symbols vary depend on the model of unit. For correct symbol, refer to relevant wiring diagram.
No. Parts name Symbol
(Electric
symbol)
Function
Outdoor
unit sensor
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Outdoor thermistor Ta R1T (Th1)
In heating operation standby due to outdoor
temperature (forcedly thermostat-off at 27°C or
higher), influence to defrost condition.
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Heat exchanger thermistor Tb R2T (Th2)
In heating operation, used for detection of
defrosting
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Discharge pipe thermistor Tdi, Tds
R31T (Th3-1)
R32T (Th3-2) Used for protection control of discharge pipe
temperature
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Suction pipe thermistor Ts R4T (Th4)
In heating operation, used for superheated degree
(SH = Ts – Te) control of outdoor electronic
expansion valve
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High-pressure sensor Pc, Tc (SENPH)
Used for high pressure control and for compressor
capacity control in heating operation.
Although the pressure (Pc) is detected, controlling
should be based on the equivalent saturation
temperature (Tc).
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Low-pressure sensor Pe, Te (SENPL)
Used for low pressure control and for compressor
capacity control in cooling operation.
Although the pressure (Pe) is detected, controlling
should be based on the equivalent saturation
temperature (Te).
Indoor unit
sensor
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Suction air thermistor Tr R1T (Th1)
Used for thermostat control and compensation of
electronic expansion valve control.
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Liquid pipe thermistor Tl R2T (Th2)
Used for superheated degree (SH = Tg – Tl) control
in cooling operation and freeze-up prevention
control.
Used for subcooled degree (SC = Tc – Tl) control
during heating operation and cancellation of hot
start (34°C) control.
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Gas pipe thermistor Tg R3T (Th3)
Used for subcooled degree (SH = Tg – Tl) control
in cooling operation.
Components
of outdoor unit
A Inverter compressor INV (MC1)
Used to conduct the capacity control (constant Te
control in cooling, constant Tc control in heating)
with inverter.
B STD compressor STD (MC2)
Used to conduct the capacity control with
compressor using commercial power supply and
inverter compressor (delayed start).
C Receiver — —
Making constant supply of liquid refrigerant to liquid
receiver and evaporator (expansion valve).
Storing excessive refrigerant
D Accumulator — —
Gas-liquid separator avoiding direct suction of
liquid refrigerant to compressor.
E
Outdoor unit heat
exchanger
— —
Working as condenser in cooling operation and as
evaporator in heating operation (air-cooled)
F
Outdoor unit electronic
expansion valve
— Y1E (20E)
Controlling so as to keep superheated degree (SH
= Ts – Te) constant (basically 5°C)
G
Hot gas bypass solenoid
valve
— Y2S (20RP)
Used for pressure equalizing and low-pressure
protection in no operation.
H Injection solenoid valve —
Y3S Y4S
(20RT)
Conducts protection control with discharge pipe
temperature (Tdi, Tds) and discharge superheated
degree (Tdi, Tds – Tc)
I Check valve — —
Prevents refrigerant from backword flow in
operation only with inverter compressor.
(Prevention of standard compressor start with
deferential pressure)
J Four way valve — Y1R (20S)
Making selection of cooling / heating cycle
(energized coil for heating)
Components
of indoor unit
K Indoor unit heat exchanger — —
Heat exchanger works as evaporator in cooling
operation and as condenser in heating operation.
(Air cooled type)
L
Indoor unit electronic
expansion valve
— Y1E (20E)
Used for superheated degree (SH = Tg – Tl) control
in cooling operation, and for subcooled degree (SC
= Tc – Tl) control during heating operation.
Avoiding liquid collection, by setting the valve as
minute opening (240 pls) in heating thermostat-off
(when compressor is on).