Pump Control; Fan Control; Heater Control; Starter Control - Daikin GYEQ20AN Service Manual

Actuator Control
3.2

Pump Control

[All modes]
• The cooling water pump is always running while the unit is operating.
3.3

Fan Control

[Cooling, cooling main, heating main A]
• The fan speed is reduced when the high-side pressure is lower than the target high-side
• The fan speed is increased when the cooling water temperature has risen beyond 90°C as the
• The fan speed is reduced when the unit enters the quiet mode.
[Heating, heating main B]
• When the low-side pressure is higher than the pressure set-point, the fan speed is controlled
• The fan speed is increased when the cooling water temperature has risen beyond 90°C as the
• The fans are stopped when defrosting is performed.
• The fan speed is reduced when the unit enters the quiet mode.
3.4

Heater Control

[All modes]
• These heaters are always running (turned ON) while the system is stopped.
[All modes]
• ON/OFF operation while stopped.
3.5

Starter Control

[All modes]
• If the engine speed reaches 800 min
• If the engine speed is lower than 800 min
• If no speed pulse is detected within 3 seconds of turning ON the starter, the system waits for 4
3.6

Compressor Clutch Control

[All modes]
• The compressor clutch is turned ON 3 seconds before the starter is turned ON.
• It is turned ON/OFF in accordance with step commands for capacity.
107
Cooling water pump
Fans
pressure.
result of reducing the fan speed.
to adjust the pressure.
result of reducing the fan speed.
Compressor heater, oil return heater
Oil separator heater, accumulator heater
the starter is turned OFF.
attempts to start the engine by turning ON/OFF the starter in the following cyclic pattern:
ON [10 seconds] → OFF [10 seconds] → ON [6 seconds] → OFF [10 seconds]
→ ON [6 seconds]
minutes before the next attempt.
-1
or higher as the result of turning ON the starter, then
-1
with the starter turned ON, then the system
SiAUY361411EA
Control and Functionality