Y-Control - Daikin ERQ Service Manual

X, Y, Z Control
2.1.1 Different levels
Inside the control box, this 0-10 VDC signal is converted into a voltage level.
The output voltage increase gives the voltage at which the level increases.
The output voltage decrease gives the voltage at which the level decreases.
Example:
Room temperature = 20°C, set temperature = 25°C. Heating operation: DDC controller,
calculates the difference and sends a 3 VDC signal (fictive value) to the control box. This is
between 1,8 and 3,8 so in level 2. When the room temperature rises to 23°C, the DDC controller
detects a smaller temperature difference and will send out a higher signal, ex. 5 VDC. The
output voltage has increased so you have to use the highest line, indicating that you are now in
level 3. When the window is opened, the room temperature drops and the difference with the set
temperature is higher. The DDC sends a 1 V signal. According to the "output voltage
decreasing" line, we are now in level 1.
2.1.2 Refrigerant target temperature
Example, continued:
3 VDC = level 2, thus meaning an increase of the refrigerant target temperature. In heating
mode, this means Tc + 1°C. Logically, the room temperature will rise so at the next signal, we
are in level 3, where Tc is kept even.
ΔT
2.2

Y-Control

Control of evaporating and condensing temperature (Te and Tc) by Daikin control (no DDC
needed).
Fixed Te or Tc
Te = user setting: -3 ~ 10°C
Tc = user setting: 43 ~ 49°C
50
0-10V
Control Box
DDC
X-control
Output level
Output voltage increasing
DDC
Output voltage decreasing
0-10V
Control Box
DDC
X-control
ΔT < 0 level 1 + level 2
ΔT = 0 level 3
ΔT > 0 level 4 + level 5
= room temp. - set temp.
level 1
level 2
level 3
level 4
level 5
Level 1 Level 2 Level 3
1.8 3.8
--> -->
1.2 3.2
<-- <--
refrigerant
target temp. cooling heating
level 1 +2 T
e+2
level 2 +1 T
e+1
level 3 0 T
level 4 -1 T
e-1
level 5 -2 T
e-2
Cooling
DDC asks less capacity
no change
DDC asks more capacity
: http://splitoff.ru/tehn-doc.html
ESIE09-05
Level 4 Level 5
6.8 8.8
--> -->
6.2 8.2
<-- <--
T
c+2
T
c+1
T
e c
T
c-1
T
c-2
Heating
DDC asks more capacity
no change
DDC asks less capacity
Control Box