Installation Operation Maintenance

OperationSetting the economizer or0-50% motorized hood(option)Note: The Unit Economizer Moduleis located in the electrical panel.Note: When the C02/VOC sensoroption is installed, the economizermust be set from the UEM board(refer to CO2/VOC sensor section inthis manual).- The electrical power must bedisconnected to set the permanentposition and check the economizer.- Disconnect the power supply, putthe thermostat fan selector to "ON"and the "HEAT/COOL" selector to"OFF". This sets the damper in theminimum ventilation position.- To set the required permanentventilation air position, turn thedial on the UEM clockwise toincrease ventilation, orcounterclockwise to decreaseventilation. The damper will openat this setting whenever the fancircuit is powered up.- When the arrow on the dial'sadjustment screw is pointing to 8o'clock, the permanent position isroughly 0%. When the dial ispointing to 12 o'clock it is roughly25%, and when the dial is pointingto 4 o'clock it is roughly 50%.(See figure 25).Notes: To check the damper isfunctioning correctly, the UEM isequipped with an indicator light atthe bottom to the left. This lightcomes on each time the motoractivates the damper to open orclose it. While setting thepermanent position, the dampermay move towards the new settingin several small steps. Once thedamper has remained in the sameposition for 10 to 15 seconds it canbe assumed it is in the newposition. When the fan circuit is nolonger powered up, the dampercloses.Figure 25 - Minimum fresh air adjustment1. Minimum position - 0% fresh air2. Minimum position - 25% fresh air3. Minimum position - 50% fresh airRT-SVX16C-E439