Head Pressure Control For Euwa/Y5-10Hb(Z) - Daikin EUWA/Y5-30HB/C(Z) Service Manual

Functional Control
1.7

Head Pressure Control for EUWA/Y5-10HB(Z)

1
Functional
description
Cooling mode
2
Picture
3
4
Fan steps in cooling
mode
5
Fan steps in cooling
mode with option
EKHP8/10K
Conclusion
2–12
The chiller types EUWA/Y5-10HB(Z) are equipped with a dual speed fan control to ensure the high
pressure when the ambient temperature is low. When no signal is sent, all fans rotate on high speed.
In cooling mode, the head pressure control is activated when the temperature decreases until 17°C (=
F5 or min. temp. for cooling speed). Fan step 2 becomes fan step 1. The control is deactivated when
the temperature increases until 19°C (= F6 or max. temp. for cooling speed).
The following picture shows the working of cooling mode:
The following table explains the 2 fans steps for EUWA5-10HB in cooling mode:
Type
EUWA5HB(Z)
EUWA8-10HB(Z)
Head pressure control enables an extra fan step when the EKHP8/10K (= kit for operation range down
to -15°C) option is installed. The following table shows the 3 fan steps for EUWA8-10HB in cooling
mode using option EKHP8/10K:
Type Fan step 1 (= very low)
EUWA8-10HB(Z) M11F= M (medium)
+ EKHP8/10K
M12F= OFF
(thermostat -4°C)
The following table gives an overview of the different fan steps according to the mode:
Mode
cooling only (5-8-10HP)
cooling only (8-10HP)+option EKHP8/10H
(thermostat -4°C)
heatpump (5-8-10HP)
Min temp (F5) Max temp (F6)
Fan step 1 (= low)
M11F= M (medium)
M11F= H (high)
M12F= OFF
Fan step 2 (= low)
M11F= H (high)
M12F= OFF
Total fan steps
2 steps
3 steps
No fan speed control. In defrost mode, the fan
card is used to put off the fans.
ESIE98–06A
Fan step 2 (= high)
M11F=H (high)
M11F= H (high)
M12F= H (high)
Fan step 3 (= high)
M11F= H (high)
M12F= H (high)
Part 2 – Functional Description