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Reco-Boxx ZXR / ZXA / Flat – Operation and maintenance instructions
[03/
2022 ]
6.2 Temperature control
There are several options available on GLOBAL units to ensure a comfortable temperature.
The options are controlled either via supply or extract air temperature.
Supply Air Temperature T5
Supply temperature control is the default setting. This involves keeping a constant supply air temperature
without consideration to the load in the premises. The supply air temperature is measured on sensor T5.
Extract Air Temperature T2
The default temperature control can be changed to Extract temperature control via the advanced setup.
The extract air temperature is measured on sensor T2. Extract air control involves keeping a constant
temperature in the extract air duct (premises), by controlling the supply air temperature. This provides a
uniform temperature in the premises regardless of the load. The internal sensor T2 can be replaced with
the optional external room temperature sensor (Art.-No. 0043.0974.
Temperature sensor positioning :
6.3 Free cooling
The free cooling function uses the lower temperature of the outside air to cool the building.
Free cooling is realized by means of the integrated 100% modulating bypass of the heat exchanger (PX)
or the stepless motor control of the rotary heat exchanger (RX). The optional output OR3-OR3 on the SA-
TIO relay indicates the position of the bypass. The contact will open if the bypass is fully closed, or close
if the bypass is fully or partially open.
The bypass (PX) or the rotary heat exchanger (RX) can be configured as on/off or modulating. This is con-
figured in ADVANCED SETUP. In modulating mode, the temperature is configured in the base setup and
the position of the bypass/stepless motor will modulate in order to maintain the setpoint. The free cooling
function is activated automatically. An on/off bypass / stepless motor operates according to the logic
below:
Free cooling STARTS if the following conditions
are TRUE:
•
The outdoor temperature (sensor T1) is lower
than the extract air temperature (sensor T2)
•
The outdoor temperature (sensor T1) is higher
than 10 C.
•
The extract air temperature (sensor T2) is
higher than 22 C.
Free cooling STOPS if one of the following
conditions is TRUE:
•
The outdoor temperature (sensor T1) is higher
than the extract air temperature (sensor T2)
plus 1 C.
•
The outdoor temperature (sensor T1) is lower
than 9 C.
•
The extract air temperature (sensor T2) is
lower than 20 C.
These Settings can be configured in ADVANCED SETUP