45
Operation and maintenance instructions
- Conditions:
• Mode Airflow control or Demand control: during the initialization of the pressure alarm. In this case, the unit must have
forward fans or backward fans with kit CA.
• Mode Pressure control: during the initialization of the pressure reference via airflow.
- Causes:
The reference pressure (Paref) cannot be identified and the fans are stopped. 4 possibilities:
1.
Actual airflow < requested airflow: The requested working point is ‘too high’ (too high pressure loss)
for the maximal available pressure at the requested airflow for this fan.
2.
Actual airflow > requested airflow: the nominal airflow requested to initialize the pressure alarm
cannot be reached because the lower limit of the fan’s operating zone has been reached.
3.
Very unstable pressure (pumping).
4.
Assigned airflow not reached after 3 minutes.
If this occurs during initializing an alarm pressure, there are 2 options:
1.
No action is taken: the control will operate without a pressure alarm.
2.
Corrective action is taken (change the working point to one located in the working
zone of the fan, by reducing the pressure system, modifying the nominal airflow…) and restart the setup operation.
If this occurs during initializing of the assignment pressure in pressure control mode: Corrective action must be taken
(change the working point to one located in the working zone of the fan, by reducing the pressure system,
modifying the nominal airflow …) and restart the setup operation.
- Effects:
8.3 TYPE 3: ALARM REPORT DURING REFERENCE PRESSURE INITIALIZATION
TAC control board
ALARM OUTPUT
AL dPa OUTPUT
LED ALARM
Fans
Alarm Status
/
ON
Stopped
Auto reset: no
Displayed on HMI TACtouch
Code
Text displayed
Level
P.20
Initialisation of the reference pressure - Unstable supply air pressure
2
P.21
Initialisation of the reference pressure - Unstable extract air pressure
2
P.22
Initialisation of the reference pressure - Supply air flow too low
2
P.23
Initialisation of the reference pressure - Extract air flow too low
2
P.24
Initialisation of the reference pressure - Supply air flow not reached
2
P.25
Initialisation of the reference pressure - Extract air flow not reached
2
P.26
Initialisation of the reference pressure - Supply air flow too high - Min. limit of the motor
2
P.27
Initialisation of the reference pressure - Extract air flow too high - Min. limit of the motor
2
