Protective Functions - Swegon CASA W4 Smart Installation, Commissioning And Maintenance Instruction

1.6 Protective functions

The heat exchanger's freeze protection
W4's defrosting function guarantees continuous and bal-
anced ventilation in the home even during extreme condi-
tions. If there is a risk of the heat exchanger in the ventila-
tion unit freezing, the preheater is activated and the speed
of the fans is changed and in doing so the heated extract
air prevents freezing inside the heat exchanger.
The fans' overheating protection
The fans have thermal overload cut-outs, which stop
them if the temperature rises too high. The controller
also stops the fans if a serious malfunction occurs in the
ventilation unit. The protective function resets itself au-
tomatically when the temperature drops or the malfunc-
tion has been remedied.
Electric air heater
The electric air heater is equipped with overtemperature
protection. If the overtemperature protection trips, you
must not continue to use the ventilation unit until the
cause of the overtemperature protection tripping has
been established and the fault has been rectified.
An automatic overtemperature protection switches off
the air heater if a fault situation arises. This protective
device automatically resets itself when the air heater has
cooled down.
The thermal overload cut out with manual reset can be
reset by pressing a button inside the ventilation unit. The
acknowledgement buttons are located next to the air
heaters. The buttons are marked in the illustrations below.
When you press the reset buttons and feel a click, the
overtemperature protection (thermal overload cut out) has
then been reset.
Ventilation unit with water-heated air heater
The ventilation unit with water-heated air heater has a
temperature sensor that protects the air heater from freez-
ing. The air heater freezing warning alarm appears on the
screen if the temperature of the water heated air heater
drops too low, but the unit continues to operate normally.
If the air heater's temperature drops further, the controller
will stop the ventilation unit to prevent the air heater from
freezing. An alarm is then shown on the cooker hood.
When the temperature of the air heater has risen suf-
ficiently, the ventilation unit and panel show a so-called
remaining info-alarm, . The Info alarm can be reset
from "Alarm" on the main menu.
Cold supply air
The ventilation unit has built-in condensation protection
on the ventilation duct. If it is discovered that the supply
air is too cold, the ventilation unit stops and an alarm is
shown the cooker hood.
Temperature sensors
If a sensor fault is detected, the ventilation unit enters
restricted mode to prevent damage to the ventilation
unit. The functions related to the current sensor in ques-
tion are deactivated and the ventilation unit works as
well as possible. The ventilation unit's function returns
to normal once the fault has been corrected.
6 www.swegonhomesolutions.com
Reset button for the over-
temperature protection on
the preheating air heater
We reserve the right to alter specifications.
W4.080219
Reset button for the over-
heating protection on the
post heating air heater
(Only models with electric
air heater)