Swegon GLOBAL PX Operation And Maintenance Instructions page 46

8.9 TYPE 9: ALARM INDICATING A T° SENSOR T1/T2/T3 FAILURE
- Conditions:
- Causes:
• One or more of the T° sensors T1/T2/T3 connected to the TAC5 circuit and mounted on heat exchanger is
defect or not connected. These sensors are needed for the bypass control and the anti-frost procedure.
- Effects:
T.10 Sensor T1 disconnected
T.11 Sensor T1 short circuit
T.20 Sensor T2 disconnected
T.21 Sensor T2 short circuit
T.30 Sensor T3 disconnected
T.31 Sensor T3 short circuit
AL1 relay
Alarm status
8.10 TYPE 10: ALARM INDICATING FAILURE ON T° SENSOR T4
- Conditions:
• Only with internal water heating coil (IBA) option
- Causes:
• T° sensor T4 located on the coil and connected to the TAC5 circuit is defective (open or short circuit) or not connected.
This is used to prevent frosting of the internal heating coil. In this case, as a safety measure, the 3-way valve is
opened and the circulator contact is closed.
- Effects:
T.40 Sensor T4 disconnected
T.41 Sensor T4 short circuit
AL1 relay
Alarm status
* unless the status has been changed in advanced setup
46
Displayed on HMI
Text displayed
TAC5 control board
O.R.1 LED ALARM
/
Manual reset mandatory.
Displayed on HMI
Text displayed
TAC5 control board
O.R.1 LED ALARM
/
Manual reset mandatory.
LED AF
ON
LED AF
ON
Operation and maintenance instructions – v2.8.8 & 2.7.3
LED ALARM LED Pa
RED
Fans
/ Stopped
LED ALARM LED Pa
RED
Fans
/ /
/
/