CIAT Connect 2 User Manual

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16.3.2 Water supply control (P141 = 2)
If heating mode is selected with a water-to-water unit, the setpoint is adjusted based on the temperature measured by the hot water supply
sensor. If cooling mode is selected and P6 = 1, the setpoint is adjusted based on the temperature measured by the heat exchanger outlet
sensor. If P6 = 2 in the same mode, it is adjusted based on the temperature measured by the manifold sensor.
The type of control used is PIDτ.
The temperature is measured periodically (τ) then compared to the setpoint and multiplied by a proportional coefficient (P) -- taking into
account the difference between the measurement and the setpoint (D) and the change in the difference between the measurement and the
setpoint (I) -- in order to approach the setpoint quickly.
Formula: DV = P (M-S) t1 +  (M-S)*I + [(M-S) t0 - (M-S) t1]*D
M = Measurement, S = Setpoint.
When P146 = 0 and P147 = 0 (standard setting), the PIDτ function becomes PT (the Integral and Derivative functions are disabled)
The related parameters are as follows:
P251: Calculated setpoint
P121: Setpoint 1 in cooling mode
P123: Setpoint 1 in heating mode
P145: P coefficient
P146: I coefficient
P147: D coefficient
P148: T coefficient
 In cooling mode:
A call is made for an additional stage if:
DV > +1.0 K for the first stage and +0.5 K for the additional
stages.
A call is made to turn off a stage if:
DV < –0.5 K for a stage and –1.0 K for the last stage.
Example: Two-stage unit with a 5°C setpoint, where D = 0 and I = 0.
 In heating mode:
A call is made for an additional stage if:
DV < –1.0 K for the first stage and -0.5 K for the additional stages.
A call is made to turn off a stage if:
DV > +0.5 K for a stage and +1.0 K for the last stage.
Example: Two-stage unit with a 45°C setpoint. I = 0 and D = 0.
16.3.3 Adjusting the setpoint to the water supply with compensation on the water return (P141 = 3):
 Aim:
Allow the control system to anticipate changes in load on the loop by monitoring for variations in the water inlet temperature.
 Action:
Adjusts the controller time delay.
 Principle:
The water return temperature is measured: θt0; evaporator in cooling mode, condenser in heating mode at time t0 then t0 + P151.
The calculated temperature variation [θt1 - θt0] is used to define the compensator coefficient.
The PID control polling time then becomes: remaining time × compensator coefficient.
Configuring the compensator coefficient: The compensator coefficient can be set to between 0.1 and 1 (parameter P150).
- If the compensator coefficient = 1 → the function is disabled.
- If the water return temperature variation < 0.5°C → no compensation.
The compensator coefficient is maximum when the temperature variation = 10°C between each time. .
P
Stage 1
Stage 2
Stage 1
Off
On
0.5
3
4
6
7
1
4
4.5
5.5
6
1.5
4.33
4.66
5.33
5.66
2
4.5
4.75
5.25
5.5
P
Stage 1
Stage 2
Stage 1
On
Off
0.5
43
44
46
47
1
44
44.5
45.5
46
1.5
44.34
44.66
45.33
45.66
2
44.5
44.75
45.25
45.9
S U P P L Y T E M P . : - x x . x °
S E T P O I N T : - x x . x °

CIAT Connect 2 Specifications

General

Brand	CIAT
Model	Connect 2
Category	Control Unit
Language	English