DAB Staged RTU w/ VFD Fan - Wiring/Configuration

4 Minute Read

|How it Works

The 75F DAB Staged RTU w/ VFD Fan profile provides basic packaged-unit control for a purely-staged system to operate within our Dynamic Airflow Balancing application.  Once you select the DAB Staged RTU w/ VFD Fan profile from the system selection, you can enable the applicable relays and the analog output for your packaged unit.  You may also re-map the equipment stages if you need more stages of cooling or heating.  Do this by selecting any of the drop-downs under 'Mapping'.  Lastly, under 'Test Signal' you may enable that relay for testing purposes.  

Below the profile configuration you can program the output voltage for the VFD during various stages of equipment operation.  

Each zone is configured for parameters such as size of damper and min/max damper positions as input for tracking in the algorithms.  A zone is assigned different priority levels based on individual needs - low, medium, high, or no priority; this lets the user designate which zones are more important than others for the operation of the AHU.  With this in mind, the system will actively monitor the average zone temperature while weighing individual priority levels.  As the load in the spaces shifts, the system will determine if an additional stage of cooling, heating or fan speed is needed.  

Cooling - When staging cooling, the algorithm will divide your stages evenly among the cooling loop output scale.  

• Cooling loop output > 0%, Cooling Stage 1   Turns On
• Cooling loop output > 50%, Cooling Stage 2   Turns On

• Cooling loop output <= 0%, Cooling Stage 1  Turns Off
• Cooling loop output <= 40%, Cooling Stage 2  Turns Off

Heating - When staging heating, the algorithm will divide your stages evenly among the heating loop output scale.  

• Heating loop output > 0%, Heating Stage 1   Turns On
• Heating loop output > 50%, Heating Stage 2   Turns On

• Heating loop output <= 0%, Heating Stage 1  Turns Off
• Heating loop output <= 40%, Heating Stage 2  Turns Off

Recirculate - When recirculating with a VFD, the default output voltage will be 4v. 

| Wiring

| Configuration

Relays 1-6 - By default are configured as a traditional thermostat connections. However, depending on your equipment, you can reconfigure (Mapping) any of these relays to act as heating, cooling, or fan. 

Relay 7 - Auxiliary relay for humidifier or dehumidifier contact. This is a wet contact. If your equipment needs a dry contact, please see wiring information for which jumper to pull from the CM board. 

Test Signal - At any point you can override the value the output the algorithm decided. This is used for troubleshooting and testing your equipment. 

Analog-out2 - Fan Speed. Customized using the 'Analog-out2 During STAGE' options below. 

Analog-out2 During 'STAGE' - Directly Set the VFD fan speed during a given Stage of mechanical conditioning. Whatever you set here is the speed the VFD will run when the given stage is calling.