Toshiba MMY-MAP0804HT8JP Service Manual page 83

<Other points to note>
1
Cooling operation under low outside temperature conditions
1) If pressure falls to extremely low levels, indoor units may be shut down via freeze prevention control based
on the indoor TC sensor.
2) If pressure falls to extremely low levels, frequency may be reduced via cooling capacity control.
3) When the discharge temperature sensor reading falls below 60°C, the frequency may be increased above
the level called for by the command received from the indoor unit.
2
PMV (Pulse Motor Valve)
1) When the power is turned on, PMVs generate a tapping sound as they are initialized. If this sound is not
heard, there is a possibility of faulty PMV operation. However, in a noisy environment, it may simply be
drowned out by ambient noise.
2) Do not separate the actuator (head section) from any PMV during operation. It may result in an inaccurate
opening.
3) When transporting (relocating) the set, do not, under any circumstances, keep the actuator separated. It
may damage the valve by causing it to close and exposing it to pressure from sealed liquid.
4) When reattaching the actuator after its removal, push it in firmly until a click sound is heard. Then, turn the
power off and back on again.
<Schematic diagram for oil equation control>
Unit
transferring oil
H e a d r e
PMV1
PMV2
TE1
PMV4
TE2
High pressure sensor
TL SVD3
SV
SV41
SV
Liquid tank
TD1
Compressor
1
SV3A
ON
u i n ( t M M - Y M A P 1 6 0 4 ) *
FM
TO
4-way valve
SV6
SV
SV
SV2
O.S.
Accumulator
SV
SV
SV42
ON
SV3C
SV43
TD2
HPS HPS
TD3
HPS
TK
Compressor
Compressor
2
3
TK2
TK1
TK3
TK5
SV3E
SV SV3F
SV3B
SV
Balance pipe
Liquid pipe
Gas pipe
Unit
receiving oil
PMV2
PMV1
TS1
High pressure sensor
TL
Low pressure sensor
Liquid tank
– 82 –
F o o l l w r e u i n ( t M M - Y M A P 1 2 0 4 ) *
FM
TE1
SV
SV5
4-way valve
Low pressure sensor
SV
SV2
O.S.
SV3D
SV
SV41 SV42
SV SV
TD2
TD1
HPS HPS
SV3C
A3 TK4
Compressor
Compressor
2
1
TK2
TK1
SV3 TK5
SV3A
SV SV3B
TO
TS1
Accumulator
ON