Humidity Sensor (Xcell 400 Qvi Model Only); Filter Monitoring (Xcell 400 Qvi Model Only); Automatic Defrost Protection For The Mvhr (Xcell 400 Qvw Model Only); Automatic Defrost Protection For The Mvhr (Xcell 400 Qvi Model Only) - Xpelair Xcell 400 QV Installation And Operating Instructions Manual

8.7 Humidity sensor (Xcell 400 QVI model only)

Refer to sections 7.6 and 7.8 for the relevant wiring diagrams.
Minimum size of 3-core cable to be used for switch connections: 0.5mm².
This product is designed to measure humidity and temperature in indoor applications.
It uses a capacitive sensor element for the humidity measurement.
At 50% RH the MVHR changes to speed 2.
At 75% RH the MVHR changes to speed 3.
Note:
When using Humidity Sensors in conjunction with the 7-Day Timer Switch a maximum of eight Humidity Sensors can
be connected. When using Humidity Sensors in conjunction with the 7-Day Timer Switch and a CO
maximum of four Humidity Sensors can be connected.

8.8 Filter monitoring (Xcell 400 QVI model only)

Monitoring of the G4 Filters in the MVHR is carried out via a time function, which can be adjusted between 2 and 6
months (factory default setting 6 months), see section 8.5.4 for further details of how to change this feature.

8.9 Automatic defrost protection for the MVHR (Xcell 400 QVW model only)

Automatic defrosting becomes active when the outgoing air temperature in the MVHR unit drops below around 3ºC
(i.e. there is a risk of ice). The supply air Fan will be switched off for 2 hours, during which only warm exhaust air will
flow into the Heat Exchanger. The Heat Exchanger will then be defrosted during this period. If the exhaust air
temperature increases from 3ºC to 8ºC within these two hours, the MVHR will switch back to normal heat recovery
operation.

8.10 Automatic defrost protection for the MVHR (Xcell 400 QVI model only)

Setting 1 (default factory setting):
Jumper 1 is not selected on the display panel.
Automatic defrosting becomes active when the outgoing air temperature in the MVHR unit drops below around 3ºC
(i.e. there is a risk of ice). The supply air Fan will be switched off for 2 hours, during which only warm exhaust air will
flow into the Heat Exchanger. The Heat Exchanger will then be defrosted during this period. If the exhaust air
temperature increases from 3ºC to 8ºC within these two hours, the MVHR will switch back to normal heat recovery
operation.
Setting 2:
Jumper 1 can be selected by removing the display panel cover screws and moving the Jumper Key onto both pins.
When using the MVHR in houses with open fireplaces, the MVHR must be set in such a way that the supply Fan
does not switch off, but instead the Summer Bypass flap is opened and the supply air flows directly into the living
area. When active the Summer Bypass flap remains open for 2 hours, during which only warm exhaust air will flow to
the Heat Exchanger. The Heat Exchanger will then be defrosted during this period. If the exhaust air temperature
increases from 3ºC to 8ºC within these two hours, the Summer Bypass flap closes automatically and the MVHR will
switch back to normal heat recovery operation.
For setting 2, an electric Defrost Heater Unit is highly recommended. The Defrost Heater Unit is fitted to the MVHR
ducting system. When a Defrost Heater Unit is being used, automatic defrosting does not occur, meaning that the
MVHR runs constantly in heat recovery mode. Please contact the UK sales office for further details, contact details
can be found on the back of this booklet.
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Jumper 1 not selected
(Factory default position)
Sensor a
2