VALLOX 180 SE
Pressure difference switch
INSTRUCTIONS FOR USE
© VALLOX • We reserve the right to make changes without prior notification.
7
2.12. Heat recovery antifrost function and preheating
• Antifrost prevents the heat recovery cell from freezing, thus ensuring proper ventilation
even in cold periods.
• Antifrost is implemented by stopping the supply air fan. The stopping function is controlled
on the basis of the measurement data given by the temperature sensor that measures the
temperature of exhaust air after the heat recovery cell.
• The supply air fan stops when exhaust air temperature falls to the setpoint (factory setting
+6
°
C) and starts when exhaust air temperature has risen to the value set (hysteresis
setting, factory s3
°
C).
Preheating
• The unit is equipped with an electric preheating radiator in order to minimise the instanta-
neous stopping of the supply air fan. This ensures a maximally even supply air flow
through the unit.
• The preheating radiator switches on when exhaust air temperature falls to the setpoint
(factory s8
°
C) and switches off when exhaust air temperature has risen to the
value set (hysteresis setting, factory s3
°
C).
• In order to ensure the operation of the preheating radiator, the setpoint of exhaust air
temperature must be higher than that of supply air fan stopping temperature.
2.13. Antifreezing function in a water-circulating post-heating unit (option)
• The antifreezing function aims at preventing a water-circulating post-heating unit from
freezing. The automatic function stops the supply and extract air fans as soon as outdoor
air temperature falls below 0
°
C and supply air temperature below +7
°
C, in which case
also the control valve becomes wide open. The control panel displays the fault message
FREEZING ALERT, irrespective of display.
• The fans start automatically as soon as supply air temperature exceeds 10
°
C.
2.14. Maintenance reminder
• The maintenance reminder switches on the maintenance reminder symbol ( ) in the main
display of the control panel at defined intervals, the factory setting being 4 months.
• The maintenance reminder symbol is symbol is reset at the control panel (see the instruc-
tions for using the control panel in Section 3.3.10.).
• The interval can be set between 1 and 15 months at the control panel.
2.15. Filter guard function
• If the VALLOX 180 SE unit is equipped with pressure difference switches monitoring the
supply and/or extract air filters, they light up the filter guard symbol ( ) in the main
display of the control panel when pressure has risen above the setpoint.
• The filter guard closes the contacts of the fault signal relay, and the filter guard symbol ( )
is seen in the main display.
• The maintenance reminder is on even during this function.
• The operation threshold for the pressure difference switch is adjusted at the pressure diffe-
rence switch regulator (0...500 Pa). Factory setting is ca. 260 Pa; the setting can be
changed if needed. With clean filters, the symbol should light up at speeds 7 and 8.
