Stiebel Eltron VRC-W 400 Utilisation Et Installation page 18

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Settings
„P14 : Supply air flow rate offset
Use this parameter to adjust the supply air flow rate during com-
missioning. The offset refers to standard ventilation and is con-
verted internally as a percentage for the other fan stages.
Example
- Nominal flow rate (stage 2): 180 m³/h
- Offset : 45 m³/h
Stage Set flow Off- Set flow
rate set rate +
Offset
0 50
1 130
2 180 45 180+45 = 225 225/180 = 1.25 180*1.25 = 225
3 235
„P15 : Humidity protection interval
If you set fan stage 0, the appliance switches to a 24 hour dormant
phase. The humidity protection control unit only starts after this.
The appliance measures the humidity of the extract air for the time
set in P16. The appliance compares the last measured value with
the limit value set in P17. If the limit value is exceeded, the appli-
ance starts to ventilate. If the limit is undershot again, the appli-
ance terminates ventilation. At this point, the humidity protection
interval restarts, at the end of which the moisture is measured.
„P16 : Start-up time for humidity measurement
The appliance measures the humidity of the extract air for the time
set in P16. The appliance compares the last measured value with
the limit value set in P17.
„P22 : Enable preheater
Effect
0 The internal preheater is completely deactivated.
1 The internal preheater is activated. In order to keep the heat exchanger
free from ice, the preheater ensures a minimum supply air temperature
with reference to the frost protection temperature adjustable in param-
eter P18.
While this parameter is being displayed or adjusted, the "frost
protection" symbol is shown on the display.
„P23 : Frost protection mode
Effect
0 At this setting, the appliance operates solely in frost protection mode. The
preheating coil control only measures the outside temperature.
2 At this setting, the appliance operates in comfort mode. In addition to the
outside temperature, the supply air temperature is also measured. The
preheating coil is controlled to ensure that the supply air temperature
does not fall below the 16.5 °C specified in the passive house criteria.
„P24 : Bypass enable temperature
To enable checking of the other parameters for the bypass, the
outdoor air temperature must be no less than the value set in
this parameter.
18 | VRC-W 400 (E)
Offset fac- internal set flow
tor rate = Set flow rate
* Offset factor
50*1.25 = 62
130*1.25 = 162
235*1.25 = 294
„P25 : Bypass blocking temperature
If the outdoor air temperature falls below this blocking tempera-
ture, the bypass is deactivated.
„P26 : Bypass hysteresis
To make cooling possible, the outdoor air temperature must be
lower than the extract air temperature by the value set in this
parameter.
To make heating possible, the outdoor air temperature must be
higher than the extract air temperature by the value set in this
parameter.
„P27 : Temperature differential for enabling the
bypass
Use this parameter to define the temperature differential that must
be exceeded for the bypass to be enabled. For the bypass to be
enabled, the following condition must be met for 60 minutes.
P3 = 2 : Outdoor air temperature > Set room temperature + P27
P3 = 3 : Extract air temp. > Set room temperature + P27
„P29 : Appliance type
This parameter is set at the factory. The parameter can only be set
after the controller assembly has been replaced.
„P30 : Temperature for enabling frost protection
The unit only activates frost protection heating if the outdoor air
temperature drops to the value that can be set in this parameter.
„P31 : Enabling of humidity-dependent flow rate
control
With humidity-dependent flow rate control, the air flow rate is
increased or decreased depending on the humidity level.
Effect
0 inactive
1 active
„P32 : Enable outdoor air condensate prevention
The condensate prevention function is intended for units without
an enthalpy heat exchangers in areas with a subtropical climate.
If the unit is in ventilation mode and this parameter has the
value 1, the unit checks the following conditions:
- Outdoor air temperature > Extract air temp.
- Extract air temp. + P33 < Outdoor air dew point
If both conditions are met, the unit switches the fans off. After
a shutdown, the unit switches on the fans cyclically and checks
whether the conditions are still valid or whether ventilation mode
can be resumed.
Interval between measurements
Duration of measurement
min 60
min 5
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