Hoval RoofVent CON-9, Design Handbook

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5 Control components in the units
The following are installed in each main unit (= fresh air unit
or supply air unit):
■ An extract air sensor
■ A supply air sensor
■ A DigiUnit terminal box (with DigiUnit controller and high-
voltage section)
The DigiUnit controller controls the individual unit, including
the air distribution, according to the specifications of the
control zone and regulates the supply air temperature using
cascade control.
The high-voltage section contains:
■ Mains power terminals
■ Isolation switch (can be operated from the outside)
■ Motor contactor for each fan
■ Fuse for the electronics
■ Transformer for the DigiUnit controller, the mixing valve
and the actuators
■ Relays for emergency operation
■ Connecting terminals for actuators and temperature
sensors
■ Control box heating
Caution
If the power supply for the DigiUnit terminal box
is interrupted, frost protection and monitoring are
not guaranteed. The only indication that a DigiUnit
controller has broken is when it is no longer displayed
on the operator terminal. You should therefore check
regularly that the display is complete.
Design
Control box Coated sheet steel
Cover screwed down
Protection level IP65
Power supply
Supply voltage 3 x AC 400 V, 50 Hz
Permitted voltage tolerance ± 10 %
Power consumption See section 'Technical
data' for the respective
unit type
Backup fuse RoofVent
®
size 6 T 20 A
Backup fuse RoofVent
®
size 9 T 25 A
Backup fuse RoofVent
®
size 10 T 32 A
Table L10: Technical data for the DigiUnit terminal box
Power supply for RoofVent
®
unit
3 x AC 400 V
50 Hz
Table L11: Mains supply
Control systems
Control components in the units