Daikin Modular T Smart ATB Installation, Use And Maintenance Manual page 52

Prevention of heat exchanger freezing
- In the presence of electrical preheating:
- the electric preheating coil will prevent the heat exchanger from freezing, by modulation, once the
outside air temperature drops below the limit value, set at 0 °C; in the event of a malfunction of the heater
or insufficient air flow for its start-up, a differential pressure switch will stop the unit until it has defrosted.
- In the absence of the electric preheating coil:
- a differential pressure switch will prevent the heat exchanger from freezing, stopping the unit when
freezing begins
The differential pressure switch will be set in accordance with the nominal air flow. If the Modular L
Smart unit works according to different criteria than that of the nominal air flow, it will be ESSENTIAL
to adjust the settings according to the following table.
Factory settings of the differential pressure switch for freezing prevention
Size
Pa
Factory settings for freeze protection - differential pressure switch:
Size 3
400
350
300
250
200
150
100
50
0
0 200
Size 4
400
350
300
250
200
150
100
50
0
0
52
03 04
300 360
Size 03
400 600
[m 3 /h]
Size 04
500 1000
[m /h]
3
05
310
800 1000 1200
1500 2000
06 07
290 340
1400
2500