Summer Bypass (Xcell 400 Qvi Model Only); Defrost Heater Unit; Fan Fault Monitoring (Xcell 400 Qvw Model Only); Fan Fault Monitoring (Xcell 400 Qvi Model Only) - Xpelair Xcell 400 QV Installation And Operating Instructions Manual

8.15 Summer bypass (Xcell 400 QVI model only)

Using a temperature sensor, the incoming and the exhaust air temperatures are monitored automatically.
The factory default setting is 24°C.
When the exhaust air temperature increases above 24°C and the incoming air temperature remains below 24°C, the
Summer Bypass flap opens automatically, allowing cool outside air to flow directly into the living area. The Summer
Bypass flap remains open until the exhaust air temperature drops below 24°C.
When both the exhaust air and the incoming air temperatures exceed 24°C, the Summer Bypass flap remains closed
until the incoming air temperature drops to below 24°C. When the exhaust air in the living area drops below 24°C, the
Summer Bypass flap closes and the MVHR runs in heat recovery mode.
The Summer Bypass temperature setting can be adjusted from 18°C to 26°C via the control panel, see Section 8.5.3.

8.16 Defrost heater unit

An electrical connection coupling for the Defrost Heater Unit is located on the top of the MVHR.
When the incoming air temperature drops below the set temperature (0°C to 3°C), the Defrost Heater Unit will switch
on and warm the incoming air prior to it arriving at the MVHR to prevent ice forming within the MVHR Heat
Exchanger.
When the incoming air temperature rises above the set temperature (0°C to 3°C), the Defrost Heater Unit will switch
off.
Note: The fly screen must be cleaned regularly.

8.17 Fan fault monitoring (Xcell 400 QVW model only)

Should the supply air Fan fail the exhaust air Fan will switch off automatically.
Fault indication:
On the Automatic 3-Speed Switch, all 3 LEDs will flash.
Should the exhaust air Fan fail the supply air Fan does not switch off.
Fault indication:
On the Automatic 3-Speed Switch, all 3 LEDs will flash.
Using the key, the supply air Fan speed can be switched down in stages until OFF is reached, whereby the fault
^
indicator will also go out. Resetting is executed by briefly switching off the mains voltage.

8.18 Fan fault monitoring (Xcell 400 QVI model only)

Should either the external air or the supply air Fan fail, the MVHR will switch off after approx. 120 seconds.
The fault is displayed accordingly, e.g. „Fresh air Fan fault‟ or „Exhaust air Fan fault‟.
Switch off the supply voltage and seek assistance from a qualified service technician to correct the problem.
The failure message is acknowledged by pressing the Enter button (S2).
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