Toshiba MMU-P0121H Service Manual page 24

Explanation of functional parts
Functional part
Solenoid
1. SV3A
valve
2. SV3B
3. SV3C
4. SV2
5. SV4 (n)
Check valve Check valve
for discharge
Check valve
for liquid line
1. PMV A
Pulse motor
(Two pcs.
valve
used)
(PMV1 +
PMV 2)
2. PMVB
(PMV3)
Oil separator
Temp. 1. TD1
sensor TD2
2. TS1
3. TK1
TK2
TK3
4. TE1
1. High
Pressure
pressure
sensor
sensor
2. Low
pressure
sensor
Balancing pipe
1) Gathers oil in the compressor case to the oil tank of compressor during OFF time.
2) Supplies the gathered oil to the balancing pipe during ON time when pressure is applied to
inside of the oil tank.
3) Supplies oil in the case directly to the balancing pipe when pressure is applied to inside of the
compressor case.
4) Reduces pressure after pressure has been applied to inside of the oil tank
1) Returns oil supplied in the balancing pipe to the compressor.
1) Applies pressure to inside of the oil tank during ON time.
2) Detects oil level with temp. system.
(Hot gas bypass)
1) Low-pressure release valve
(To protect lowering of low pressure which is difficult
to activating time of Modular multi type)
2) Protects liquid refrigerant gathering in accumulator.
3) Gas balancing in STOP time.
(Activation compensating valve for fixed-speed compressor)
1) For activation of gas balance
2) Deflates gas in discharge pipe. (Protects liquid stagnation in discharge pipe.)
1) Protects counter pressure when the inverter compressor is operating and the constant speed
compressor stops.
2) Decreases activation load when fixed-speed compressor is activated.
(Shared function with SV4 (n) valve)
Prevents liquid accumulation in heat exchanger of the stopped outdoor unit.
(Connector CN300, 301 : White)
1) Control function for super heat volume in heating operation
(Refrigerant split flow between outdoor units)
2) Liquid line shut-down function while the fixed-speed units stop
3) Liquid line counter-pressure preventive control function during defrost operation
4) Fixed with FULL OPEN in cooling operation.
(Cooling bypass) (Connector CN302 Red)
1) Liquid bypass proportional control function for releasing discharge temperature
(Adjustment of refrigerant drying degree during inner reducing operation)
2) Releases low pressure.
1) Early protection of oil level down (Decreases flow-out of discharge oil to cycle)
(TD1 : Connector: Red, TD2 : Connector: White)
1) Used to protect discharge temperature of the compressor.
2) Used to control cooling bypass for releasing discharge temperature.
(Connector: White)
1) Used to control super heat of PMV in heating operation.
2) Used to control cooling bypass for releasing discharge temperature.
(TK1 : Connector: Black, TK2 : Connector: Blue, TK3 : Connector: Green)
1) Used to detect oil level judgment. (TH1, TK2)
2) Used to detect dilution status of oil. (TK3)
(Connector : Blue)
1) Used to control the cooling fan.
2) Used to control defrost operation in heating operation.
3) Used to control the heating fan.
(Connector : Red)
1) Used to detect high pressure, and compressor capacity.
2) In cooling operation, it is used to detect high pressure, and control the fan in cooling low
ambient conditions.
(Connector : Blue)
1) In cooling operation, it is used to detect low pressure, and control the capacity of the
compressor.
2) In heating operation, it is used to detect low pressure and control super heat.
1) Oil supply path for balancing oil of each outdoor unit.
2) Low-pressure bypass function between outdoor units, which recovers the liquid refrigerant
stagnated in the stand by outdoor unit.
3) Low-pressure balancing pipe function to secure pressure difference when check valve of
every outdoor units aligned on a circuit in parallel are inverted.
Functional outline
(Compressor case bypass)
1) Stirs oil to prevent oil separation into
* It is provided to the Cooling Only model only.
* It is provided to the Heat Pump model only.
3-21
two layers.