Carrier CCU - Using the Weekly Program; 9 Control

8.3 - Using the weekly program
Weekly program
V E N T I L A T I O N O N T I M E R P R O G R A M
P R O G . : 0 1 A C T I V A T E D E A C T I V A T E C O N F I R M
S C H E D U L E : 0 0 : 0 0 0 0 : 0 0 N O
D A Y : M O T U W E T H F R S A S U 0 : M E N U
The rst line indicates the timer channel (example VENTILATION ON). On the second line, the digit indicates the step for the programme
currently being viewed. With the cursor positioned on the
⇔
box, use the ⇑ and ⇓ buttons to scroll through the program steps.
The third line is used to enter the time for activating and deactivating the displayed program step. You can enter the hours and minutes
using the number pad.
With the cursor positioned on the NO box, press the ⇑ button to bring up the word "YES"; this program step is taken into account.
Press the ⇓ button to bring up the word "NO"; this program step is not taken into account. The cursor switches to the "NO" box after
having moved to the fourth line.
The fourth line is used to select the days of the week. They are in the following order: Monday, Tuesday, Wednesday, Thursday, Friday,
Saturday, Sunday.
Position the cursor on the selected day and press the ⇑ button to bring up the abbreviation for the day or press the⇓ key to clear the
text. Only the displayed days are taken into account.
Each operating day needs to be programmed.
The text "0: MENU" is only displayed if the cursor is on the
⇔
box on line 2. In this position only, the 0 digit key can be used to return
to the previous menu.
9 - CONTROL
■ Progressive control
This may be proportional or proportional integral.
- Proportional control
To obtain the strictly proportional, set the integral time (setting conguration) to the value of 0 seconds. Control is carried out
continuously. At each scan, the controller compares the measurement and the setpoint and calculates the control value proportionally
to the discrepancy. With this type of control, there is always a discrepancy between the measurement and the setpoint.
To stabilise the control, the proportional band must be increased. This type of control is recommended if all stages are controlled
as on/off (example: electric heater, direct expansion coil).
- Proportional-integral control
Proportional control is carried out continuously (see above). The integral calculation is carried out every 15 seconds. The value
obtained is added to that calculated proportionally. The proportional action allows the response to the measurement to be
accelerated based on the discrepancy between the measurement/setpoint. A high proportional band value allows the control loop
to be stabilised, but decreases the response speed. A value which is too large will lead to oscillations of a high amplitude during
start-up.
The integral action allows this discrepancy between the measurement and the setpoint to be cancelled. A high integral time allow
the control loop to be stabilised, but increases the time taken to cancel the discrepancy.
- Staged control
If the value measured differs from the setpoint upwards or downwards depending on the type of control to be obtained, the rst
stage is triggered. If this value differs from the differential calculated between stages, the second stage is triggered, and so on
and so forth
■ Control of the "Target" temperature
This is proportional or proportional integral.
- Cooling control
The master control is increased if the temperature exceeds the setpoint.This value is broken down according to the parameter
settings (unit type parameter) and is:
• Progressive for the chilled water valve control.
• Staged for condensation unit control.
• Progressive for the control of the fan speed controller. This slave control exists regardless of the parameter settings.
• Staged for indicating that the upper temperature limit has been exceeded.
• Gradual limitation of the cooling demand if the lower supply air limit setpoint has been exceeded. (Progressive on W, staged on
X model).
Depending on the strictly proportional composition of the unit, a discrepancy may remain between the setpoint and the measurement,
even with all the elements at 0.
- Heating control
The master control is increased if the temperature drops below the setpoint. This value is broken down according to the parameter
settings (unit type parameter) and is:
• Progressive for the electrical current or hot water valve control.
• Progressive for the limitation of the dehumidication control. This slave control exists regardless of the parameter settings.
• Staged for indicating that the lower temperature limit has been exceeded. Depending on the composition of the unit, as strictly
proportional, a discrepancy may remain between the setpoint and the measurement, even with all the elements at 0.
8 - WEEKLY PROGRAMMING (MENU 5)
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