The HyperStat 4-Pipe Fan Coil Unit (4PFCU) profile replaces the earlier SmartStat 4-Pipe FCU profile and provides enhanced zone-level control for 4-pipe fan coil systems using the next-generation HyperStat controller.
For more information, refer to the HyperStat 4 Pipe FCU (Fan Coil Unit)
| How it Works
A Smart Stat can be used to control a 4 Pipe Fan coil using the wiring schematic below and pairing it as a 4 Pipe Fan Coil. The unit will operate as follows under standard conditions (standard conditions are often adjustable)
Cooling Mode - The cooling valve will engage as soon as your current temp rises above your cooling setpoint (CSP). Stage 1 will disengage when you drop below CSP - Hysteresis value.
Heating Mode - The heating valve will engage as soon as your current temp drops below your heating setpoint (HSP). Stage 1 will disengage when you rise above HSP + Hysteresis value.
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 the 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 the Fan high will run when the space temp is more than 3 degrees from the setpoint.
As a further explanation of the cooling control, you can see from the example in the diagram below, there is a desired cooling setpoint of 74F, with a 2-degree Deadband and a .5-degree hysteresis. As the zone warms past the Cooling Deadband (desired setpoint), the cooling valve will open, and the first stage fan will engage. If the zone temperature rises another 2 degrees, the second stage fan will engage. When the zone temperature starts declining, the second stage fan will disengage once it reaches Cooling Deadband (74F in this example). The zone will continue to cool to the hysteresis value (73.5F in this example), at which point, the fan will disengage and the cooling valve with shutting."
The diagram below shows the application of the Hysteresis Band and its role:
| Wiring
| Configuration
Once you've paired the SmartNode as a 4 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 set point |
| 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. |
| Water Valve - Energize in Heating | Activated when the central plant is in cooling, but this particular zone is below the setpoint. |
| Water Valve - Energize in Cooling | Controls the water valve to keep the zone close to 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. |
| Use External 10k Temp Sensor | Only select if you are using an external 10k sensor for room temperature detection. This will disable the temperature sensor mounted in the Smart Stat and only use the remote sensor. |
Comments
1 comment
This article is referring to 2Pipe. Needs to be updated for 4pipe.
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