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Operation and maintenance instructions
Frost protection heating and cooling coils
The water coils are always protected against freezing by
an anti-frost temperature sensor. This sensor is monted
on the surface of the water coil. When the anti-frost
protection temperature of the hydraulic coil detects a
tempeature lower than 4°C (default), the pump contact
is closed and the 3 way valve is opened 100% during 15
minutes. If the unit is running, the alarm is activated
immediately. For a water preheating coil, the frost alarm
is delayed by 2 minutes. If frost protection conditions
occur when the air handling unit is OFF, the alarm is
delayed by 5 minutes.
Setting
Settings
range
Factory
setting
Internal heating coil
-10...+10°C
+4,0°C
External heating coil
-10...+10°C
+4,0°C
External cooling coil
-10...+10°C
+4,0°C
Internal preheating coil
-10...+10°C
+4,0°C
Freecooling
The bypass on the GLOBAL product range, can be config-
ured for freecooling. The main parameters to activate the
free cooling function are the outside temperature (T1)
and the extract (room) air temperature (T2). When there
is maximal freecooling possibility the bypass will be 100%
open. The 100% opened bypass can activate the config-
urable freecooling airflow.
Setting
Settings
range
Factory
setting
Outdoor T°
0...27°C
10,0°C
Extract/Room T°
6...28°C
22,0°C
Supply airflow
(l/s, m³/h)
Extract airflow
(l/s, m³/h)
Bypass control
Frost protection
Freecooling
Frost protection &
free cooling
Freecooling
Frost protection
Frost protection plate heat exchangers (PX)
In environments where the extract air can occasionally
be humid, the defrosting function can be activated to
protect the heat exchanger from frosting. There are four
strategies: down control of the supply air volume, modu-
lating by-pass control, modulation of capacity of a pre-
heating coil, differential pressure measurement (cold cli-
mate option). If non of these measures are effective, the
air handling unit can be stopped by limting the minimal
supply air temperature. When the Frost protection cycle
is active, it will be indicated on the HMI. The configurable
temperatures are exhaust temperatures.
Setting
Settings
range
Factory
setting
T° Low
1...3°C
+1,0°C
T° High
1...5°C
+5,0°C
Stop supply airflow
No
Yes
Yes
Frost protection rotary heat exchangers (RX)
In environments where the extract air can occasionally
be humid, the defrosting function can be activated to
protect the heat exchanger from frosting. The speed of
the rotating heat exchanger is linked to the tempera-
ture of the outdoor (sensor T1). When the Frost pro-
tection cycle is active, it will be indicated on the HMI.
Setting
Settings
range
Factory
setting
Activate Frost protection
-29...+99°C -9°C
RX rotation speed
2...10RPM
2RPM
Frost protection cycle active
Frost protection alarm
Frost protection
Nominal
Rotation speed
