The HyperStat 2-Pipe Fan Coil Unit (2PFCU) profile replaces the earlier SmartStat 2-Pipe FCU profile and provides enhanced zone-level control for 2-pipe fan coil systems using the next-generation HyperStat controller.
For more information, refer to the HyperStat 2 Pipe Fan Coil Unit (2PFCU)
| How it Works
A Smart Stat can be used to control a 2 Pipe Fan coil using the wiring schematic below and pairing as a 2 Pipe Fan Coil. The unit will operate as follows under standard conditions (standard conditions are often adjustable):
Heating or Cooling? The central plant will dictate whether hot or cold water is being supplied to the FCU. The Smart Stat will recognize whether the central plant is heating or cooling based on supply water temp (SWT). The plant will be said to be heating if SWT > 85 and will be said to be cooling when SWT < 65 default.
Cooling: When there is a call for cooling from the space and the SWT < 65 then the fan and valve will energize until the desired temperature is achieved. When there is a call for cooling in the space and the SWT > 65 then the valve will close, and the fan will be set to a user-defined setting or will be off if set to auto.
Heating: When there is a call for heat from the space and the SWT > 85 then the fan and valve will energize until the desired temperature is achieved. When there is a call for heating in the space and the SWT < 85 then the valve will close and the fan will be set to a user-defined setting or will be off if set to auto.
Fan Staging: You can control 3 stages of the fan. There are 5 modes for fan control; Off, Auto, Fan Low, Fan Medium, and Fan High. If you choose Low, Medium, or High the fan will run at that level all the time during occupied hours. The auto fan will run Fan low whenever the space temp is 1 degree off from desired, the Fan medium will run when the space temp is 2 degrees from desired, and Fan high and all speeds will run when the space temp is more than 3 degrees from setpoint.
Water Sampling: If there is a call for heating or cooling when the SWT is below the heating threshold and above the cooling threshold (SWT said to be neither heating nor cooling) then cycle the valve for 2 minutes every 5 minutes. This is what is called sampling. If the valve has not opened in the last hour on a call, the valve will open for 2 minutes of flow to ensure that the SWT is being accurately measured and the water does not stagnate.
The diagram below shows the application of the Hysteresis Band and its role:
| Wiring
| Configuration
Once you've paired the SmartNode as a 2 Pipe Fan Coil profile, you will need to select a few specific configuration parameters that define the physical characteristics of your box.
| Configuration Parameters
| Parameters | Usage/Purpose/Trigger |
| Fan Medium Speed | Activated when space temp is 2 degrees from the set point and an |
| Fan High Speed | Fan high and all speeds will run when space temp is more than 3 degrees from setpoint. |
| Fan Low Speed | Activated whenever the space temp is 1 degree off from setpoint |
| Aux Heating Stage 1 | Activated when the central plant is in cooling, but this particular zone is below the setpoint. |
| Water Valve | Controls the water valve to keep the zone close to the setpoint. |
| Airflow Temperature Sensor | Only selects If using an airflow sensor. These are helpful for troubleshooting. |
| Supply Water Sensor | Required for gauging the supply water temp. |
| Enable Occupancy Setting | Select if you would like to use the Occupancy Setting for setpoint control. |
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