Swegon GLOBAL PX Operation And Maintenance Instructions page 49

8.14 TYPE 13: ALARM INDICATING HEAT EXCHANGER FROST PROTECTION ALERT
- Conditions:
• Only with post-heating option
- Causes:
• For PX units:
Frost protection is only selected with electrical pre-heating coil (KWin) or water preheating coil (BAin) or modulating
bypass.
With KWin or BAin option: In certain air T° conditions as measured on the exhaust airflow after heat recovery, indicating
that the internal electrical KWin coil or external hydraulic coil (BAin) has reached its limit, the TAC5 control can take
over to guarantee the anti-frost function.
If T° < assignment T°-1,5°C for more than 5 minutes: supply and exhaust airflow reduction of 33% if airflow control or
demand control and of 25%
if pressure control mode, for 15 minutes.
• For RX units:
When outdoor temperature (T1 sensor) is lower than the anti-frost temperature (T°AF, -9°C by default), the rotation
speed of the heat exchanger will decrease to avoid any risk of frosting.
When T1 ≥ T°AF for at least 5 minutes, the wheel will ramp up to its nominal rotation speed.
- Effects:
A.10 Anti-freeze - Reduced air flows
AL1 relay
/
Operation and maintenance instructions – v2.8.8 & 2.7.3
Displayed on HMI
Text displayed
TAC5 control board
O.R.1 LED ALARM
/
Auto reset: yes
LED AF
ON ON
LED ALARM LED Pa
RED /
Fans
/
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