| Where the OptymaTM controller is directly connected to the compressor, of the condensing unit, the compressor is powered from the internal relay of the controller, therefore, it is necessary to set the programming variable AU to activate the pump down function. |
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| To set the AU variable you will need to access the Level 2 programming (Installer level), this is done by selecting the UP (^) and DOWN (v) keys and the LIGHT key simultaneously for a few seconds. |
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When the first programming variable appears the system automatically goes to stand-by.
- To select the required variable to be modified press the UP (^) and DOWN (v) keys. When the variable is selected it is possible to:
- View the setting by using the SET key.
- Modify the setting by holding the SET key and pressing the (^) or (v) key.
- When configuration settings have been completed you can exit the menu by pressing the (^) and (v) keys simultaneously and keep them pressed until the room temperature reappears.
- Changes are saved automatically when you exit the configuration menu.
- Press the STAND-BY key to enable electronic control.
As previously stated the variable for selecting pump-down is AU which must have a value of 4 as shown in the list below:

With AU = 4 the pump-down function is activated (for version with AUX/Alarm relay only). Connect the pump-down pressostat on the digital input INP-1.
The compressor is directly controlled by this pressostat.
Connect the evaporator solenoid valve on the AUX relay. The solenoid is controlled directly by the thermostat.
