Actuator Control; Electric Motor Operated Valve Control - Daikin GYEQ20AN Service Manual

Actuator Control

3. Actuator Control
3.1

Electric Motor Operated Valve Control

[Cooling]
• Adjusts the refrigerant amount in the condenser to the optimal level.
• SV8 is closed (turned OFF).
[Cooling main, heating main A]
• Adjusts the refrigerant amount in the condenser to the optimal level.
• Adjusts the fluid pressure to the optimal level.
[Heating, heating main B]
• These valves are normally controlled to the target of SHS2 = 7°C so that refrigerant flows into
• When the discharge temperature exceeds 100°C, these valves are controlled to the minimum
[Cooling/heating, heating main B]
• Adjusts the refrigerant remaining in the accumulator and the return amount of the refrigerating
∗ The same as the EV1operation.
[Cooling main, heating main A]
• Normal, fully closed opening degree
[Cooling]
• This valve is opened when the cooling water temperature is low and the low-side pressure
• When the engine is running at the minimum speed and yet the high-side pressure is higher
[Cooling main, heating main A]
• When the high-side pressure is higher than the high-side pressure set-point, hot gas is
• When the low-side pressure is lower than the low-side pressure set-point, hot gas is bypassed
[Heating, heating main B]
• When the engine is running at the minimum speed and yet the high-side pressure rises, the
[Cooling/heating]
• The opening degree of this valve is adjusted to cool the liquid refrigerant in the SC receiver by
• When the discharge temperature exceeds 105°C, liquid is injected into the intake side.
[Cooling]
• Keeps SH at the SC receiver outlet at a constant level.
• When the engine is running at the minimum speed and yet the low-side pressure is lower than
103
EV1, SV8
the evaporator at an optimal flow rate.
target of SHS5 = 4°C.
EV2
machine oil.
EV3
falls below the low-side pressure set-point during transition.
than the predetermined level, hot gas is bypassed to lower the high-side pressure.
bypassed to lower the high-side pressure.
to raise the low-side pressure.
opening degree of this valve is adjusted to maintain the high-side pressure at the target.
("Overload Capacity" control function in basic control)
EV4
keeping SHS4 at the SC receiver outlet at a constant level.
the low-side pressure set-point, keeps the low-side pressure at a constant level.
SiAUY361411EA
Control and Functionality