Alarm 7 Supply air fan, Flashing 7 on the control panel
Switch off the power supply to the unit and wait at least 2 minutes
Open the unit hatch
Spinning fan wheel by hand to rotate easily without noise
Check for bearing faults or if impeller catches on inlet cone
Switch on power supply to unit
Press button 1 on the control panel to switch the unit to the lowest operating mode
NOTE! at low outdoor temperature, the supply air fan may be delayed 1 minute
Check parameter 91 via the control panel
Press buttons 1 and 3 simultaneously for about 2 seconds until the number 1 appears on the panel
Press button 3 until the number 91 appears on the panel
Press and hold button 1 to read the parameter value
The parameter value shall be 2 for A390T, A400S, A600ST and A900ST and 1 for all other units
Change parameter 91 if the value is incorrect according to the following instruction
Option 1 for control panel labelled AVC-02 Switch off power supply to the unit
Press and hold the release button on the circuit board and switch on the power supply at the same time
Press and hold the release button until 4 LEDs next to the release button light up alternately
Release the acknowledge button
Press button 3 until the number 91 appears on the panel
Hold down button 1 and simultaneously press button 3, set 2 for A390T, A400S, A600ST, A900ST and 1 for all other units
Release button 1
Press button 3 until the digit window goes out
Option 2 for control panel labelled acetec
Change parameter 91 as instructed in the leaflet in programming mode 2
Open both fan connectors (2 cross screws in the connector loc) and check the attachment of cables
Switch on power supply to unit
Measure in the connector closest to the fan between terminals A and B where there should be 230V AC voltage and between terminals C and D there should be between 2 to 10V NOTE! DC voltage
Also check that there is contact between E and terminal 13 on the circuit board
Switch off power supply to unit
Check cables on terminals 11 to 15 on the circuit board by pressing the orange button, check the stripping approx. 7-10 mm, twist together, press the orange button, reattach the cable and release the orange button to lock the cable.