External Connections (Connection Board); Troubleshooting - SystemAir SAVE VTR 300/B Installation Manual

6.3.2

External connections (Connection board)

External connections to the main circuit board are done via connection board situated outside of the unit.
Position Description
1
Connection to the main circuit board
2
Connection for external control panel (HMI) or Internet access module (IAM)
3
Modbus RS485 connection
AI6–7
Freely configurable Analog input. None/Input type selection in HMI.
DO1–4
Freely configurable Digital output. None/Output type selection in HMI.
AO3–5
Freely configurable Analog output. None/Output type selection in HMI. Actuator type 0–10V, 10–
0V, 2–10V, 10–2V.
UI1
Digital input configured for pressure guard.
UI2
Digital input configured for cooker hood.
UI3–5
Freely configurable Universal input. Can be configured to act as Analogue input (0–10V) or as
Digital input (24V). None/Input type selection in HMI (NC or NO polarity).
24V Maximum current 200mA at 24VDC +-10%.
6.4

Troubleshooting

If problems should occur, please check the items below before calling your service representative.
Fans do not start
1. Check the control panel for alarms.
2. Check that all fuses and fast couplings are connected (main power supply and fast couplings for supply and extract
air fans).
3. Check the week schedule. Fans may be set to OFF in the Schedule airflow settings menu.
Reduced airflow
1. Check the control panel for alarms. Some alarms can reduce the airflow to LOW if active.
2. The unit could be in defrost mode. This reduces the fan speed and in some cases shuts down the supply air fan com-
pletely during the defrosting cycle. The fans go back to normal after defrosting. There should be a defrosting function
icon visible on the home screen if defrosting is active.
3. Speed of fans is linearly reduced when the outdoor air temperature is below 0°C and an outdoor airflow compensa-
tion function is enabled.
4. Check if temporary user mode that reduces airflow is not activated, for example Away, Holiday, etc. Also check dig-
ital inputs Central Vacuum Cleaner and Cooker Hood.
5. Check the airflow settings in the control panel.
6. Check week schedule settings (chapter 5.7.3).
7. Check filters. Is change of filters required?
8. Check diffusers/louvres. Is cleaning of diffusers/louvres required?
9. Check fans and heat exchange block. Is cleaning required?
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Fig. 13 External connection box and board
Service | 33