Daikin GYEQ20AN Service Manual page 115

SiAUY361411EA
[Cooling main, heating main A]
• Keeps SH at the SC receiver outlet at a constant level.
• When the low-side pressure is lower than the low-side pressure set-point, keeps the low-side
[Heating, heating main B]
• Keeps SH at the SC receiver outlet at a constant level.
• These valves are normally controlled to the target of SH3 = 20°C so that refrigerant flows into
• When the discharge temperature exceeds 100°C, these valves are controlled to the minimum
[Cooling]
• When the engine is running at the minimum speed and yet the low-side pressure is lower than
[Cooling main, heating main A]
• When the low-side pressure is lower than the low-side pressure set-point, keeps the low-side
[Heating, heating main B]
• These valves are normally controlled to the target of SHS3 = 20°C so that refrigerant flows
• When the discharge temperature exceeds 100°C, these valves are controlled to the minimum
[All modes]
• Adjusts the compressor oil return temperature to the optimal value.
[Heating, heating main B]
• When the fluid pressure is higher than the fluid pressure set-point, adjusts the fluid pressure
[Cooling, cooling main, heating main A]
• If the high pressure cannot be maintained at the pressure set-point, synchronizes with SV3A
[Cooling main, heating main A, heating, heating main B]
• When the fluid pressure drops and reduced performance of the cooling indoor unit occurs,
[Cooling, cooling main, heating main A, heating, heating main B]
• Adjusts the evaporation amount by setting the refrigerant amount that flows into the waste
[Cooling]
• This valve is closed (turned OFF).
Control and Functionality
pressure at a constant level.
the waste heat recovery heat exchanger at an optimal flow rate.
target of SH = 7°C.
EV5
the low-side pressure set-point, the waste heat recovery heat exchanger is used as an
evaporator. In this case, the opening degrees of these valves are adjusted to keep the low-
side pressure at a constant level.
pressure at a constant level.
into the waste heat recovery heat exchanger at an optimal flow rate.
target of SHS5 = 7°C.
EV6
EV7
by making the receiver gas flow to the low pressure side.
EV3A
and 3B to maintain the high pressure.
EV3B
maintains the receiver outlet pressure.
MV (water motor-operated valve)
heat recovery heat exchanger to the optimal level.
SV1
Actuator Control
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