X-Control - Daikin ERQ Series Service Manual

ESiEN09-06 A
2.2

X-Control

Control of refrigerant temperature by means of an external device (DDC controller, 0-10 V
control).
output
10V
T = T
T
measured
Components for control:
++
--
In case of X-control, a DDC-controller is needed to operate the unit. This DDC-controller is field
supply but in order to connect it to our ERQ-system, it is required that it emits a 0-10 VDC signal
towards the control box.
2.2.1 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.
Control Box EKEQ - CBV3
T
measured
DDC
5V
0V
T
set
T
set
- T
set measured
= T , T or T
d s r
DDC (field supply)
Air thermistor (field supply)
BRC1D (only for servicing)
Possibility for T , T
d s
Flexibility in applications
Higher cost (DDC needed)
0-10V
Control Box
DDC

X-control

Output level
Output voltage increasing
DDC
Output voltage decreasing
0~10 V
or T control
r
level 1
level 2
level 3
level 4
level 5
Level 1
1.8
-->
1.2
<--
W-, X-, Y-, Z-Control
Level 2 Level 3 Level 4
3.8 6.8
--> -->
3.2 6.2
<-- <--
Level 5
8.8
-->
8.2
<--
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