Bypass; Frost Protection Strategies; Switching Contact (Potential-Free) - Aerex Rls T1 Sys Montage- Und Betriebsanleitung

9 Special functions
ited period of time if the ventilation level is manu-
ally adjusted. The duration of manual operation
depends on the Duration of Ventilation Level
parameter.
The operating mode can be selected from any
main control unit. If nominal ventilation is called
up with a single control unit (solo mode), the vent-
ilation unit also switches to Auto Sensor.

9.2 Bypass

All units are fitted with a bypass controller. This
ensures passive cooling of the building (if the
conditions for this are met) and that the temperat-
ure does not fall below the minimum supply air
temperature during cooling.

9.3 Frost protection strategies

Units with preheating register
The electric heat register keeps the unit free of
frost and protects the heat exchanger from icing
over. The ventilation unit controls the temperature
at the unit inlet to the minimum air inlet temperat-
ure (factory setting -1°).
Comments: The minimum air inlet temperature is
set on units with an enthalpy heat exchanger and
preheating register.
If the outgoing air temperature falls below the
Outgoing air min. value set in the factory (with a
defective electric heat register), the ventilation
unit switches off. A frost protection fault appears
on the control unit.
If the heater power rating is not sufficient for ex-
treme conditions (high volumetric flow and very
low outside temperature), the ventilation unit
switches back one ventilation level.
Units without preheating register
If the outgoing air temperature falls to the set
value T outgoing air min. (fixed factory setting),
the supply air fan switches off (regardless of heat
exchanger type).
If further exhaust air causes the outgoing air tem-
perature to increase again (set increase in tem-
perature in outgoing air, fixed factory setting), the
supply air fan switches on again.
If using another upstream, controlled form of pre-
heating (electric pre-heating), the pre-heating is
used to keep the unit free of frost. Should the out-
going air temperature fall below the set "Outgoing
air min." despite this, the ventilation unit switches
to fault after a short delay time.

9.4 Switching contact (potential-free)

Functions which can be switched with the poten-
tial-free contact on the main circuit board:
• Alarm
• Filter change
• Operating display
• Supplementary heating
• Pre-heating
• Shutter
• Brine EHE (unregulated pump)
• Cooling function
Alarm function: Switching contact open during
operation. In the event of a fault, the contact re-
mains closed until acknowledged.
Filter change function: The switching contact
closes if a filter change is imminent.
Operating display function: If fans are switched
to active (in ventilation level HPV, RV, NV or IV),
the switching contact closes. The contact remains
open when switching off or in the event of a fault.
With pre-heating/supplementary heating:
Incorrect installation will result in unit dam-
age. If external pre-heating or supplementary
heating is selected, the power supply for the
component should be switched via an external
relay.
Supplementary heating function: The switching
contact switches a downstream heat register on/
off. The setting function of the supply air temper-
ature is activated in the Temperature short code
menu. The supplementary heat register's supply
voltage is led via an external relay and not via the
contact on the basic circuit board.
Supplementary heating on: Switches on auto-
matically when the temperature falls below the
room setpoint temperature.
Supplementary heating off: Switches off auto-
matically when the actual room temperature ex-
ceeds the room setpoint temperature. The actual
room temperature is determined using the selec-
ted temperature sensor.
Pre-heating function: The switching contact
switches an upstream external pre-heating unit
(electric/hydraulic) on/off. The pre-heating keeps
the unit free of frost.
Pre-heating on: Switches on automatically if the
temperature falls below the minimum air inlet tem-
perature (factory setting) + T air inlet offset heat-
ing.
Pre-heating off: Switches off automatically if the
minimum air inlet temperature (factory setting) +
T air inlet offset heating is exceeded.
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