Solutions - Fan Coil control
Description
The PIERRE system supports fan coil unit (FCU) control through several interface methods, depending on the requirements of the HVAC equipment.
1. Relay-Based Control
Fan coil units can be controlled using the digital relay outputs of a PIERRE Controller. This configuration can be used for:
- Fan coil On/Off control
- Low / Medium / High fan speed selection
- Heating / cooling valve control
The required number and configuration of relay outputs depends on the specific fan coil unit and its control interface.
2. 0–10 V Control
For fan coil units with 0–10 V control inputs, PIERRE can provide analogue control signals for functions such as:
- Automatic Fan speed control
- Fan coil On/Off control
The exact control method depends on the input configuration and requirements of the connected fan coil unit.
3. Modbus Control
Fan coil units supporting Modbus can be integrated with PIERRE through the supported Modbus interface.
Depending on the FCU model and its available registers, PIERRE can control and/or monitor parameters such as:
- Operating mode
- Setpoint
- Fan speed
- Heating / cooling state
- Room temperature
The available functions depend on the Modbus implementation of the specific fan coil unit.
4. Temperature-Based Control
A temperature sensor can be used as an input for FCU control logic. The measured temperature can be used together with the configured setpoint and operating mode to control the connected FCU.
The actual control logic depends on the selected FCU interface and the configuration of the PIERRE system.
The 0–10 V Extender is suitable for controlling dimmable lights, fan-coil units, valves/actuators, and other 0–10 V controlled devices, provided that the device’s 0–10 V control input has a maximum short-circuit current of 1 mA. In other words, it is intended for low-current 0–10 V control signals, not for powering a load directly. If the controlled device sources more than 1 mA into the 0–10 V control line, it should not be connected directly to the extender.
Schemes
Fan Coil - Electric schemes
Schemes - 0-10V Extender is required for Fancoils with 0-10V control
PWM to 0-10V adapter - Electric schemes
Cables
| Position | Wires | Diameter | Type | Comment |
|---|---|---|---|---|
| From relay to HVAC with blower speed | 6 | 1.5 mm² | NYM-O | valve |
| DC and Signal | 5 | 0.75 mm² | H07V-K | VALVE, SPEED 1, SPEED 2, SPEED 3, N, PE |
| From Temperature sensor to PIERRE | 3 | cat.5 | UTP | +5V, GND, SIGNAL |
| From Temp Sensor to PIERRE | 3 | cat.6 | J-Y(St)Y | +5V, GND, SIGNAL |
Troubleshooting
Use one relay per speed and check that the order in the app (low, medium, high) matches the wired relays. Only one speed relay may be closed at a time — the Smart PIERRE fan-coil I/O interlocks them; if you wire the speeds to plain relay outputs, add the interlock in the automation.
If the power goes out, smart devices will retain their last state and resume functionality when power is restored. For critical devices, battery backups can be used to maintain operation during an outage.
No, a classic thermostat is not necessary. Instead, a temperature sensor integrated with the PIERRE system can monitor the room’s temperature and manage the heating/cooling devices accordingly.
Yes, PIERRE offers its own smart thermostats, which can be found in the thermostat product category.
Yes, you can replace an old thermostat with a PIERRE display, as long as the display includes a temperature sensor for temperature monitoring.
Yes, most PIERRE displays have built-in temperature sensors and can control heating/cooling systems just like a thermostat. All displays have relays that can send signals to heating/cooling devices to turn them on or off.
Heat meters with an M-Bus interface are read through an Intesis M-Bus to Modbus gateway connected to a PIERRE Pro controller. The meters are wired to the gateway's M-Bus (a shared two-wire bus) and the controller reads them over Modbus RTU.
Yes, you can control the temperature room by room.
The circulation pump’s operation is based on automation, so if the valve in any apartment’s floor heating system is activated, it simultaneously activates the circulation pump. If separate control is needed, it can only be handled locally within the apartment.
Each apartment measures its own temperature and humidity and controls the valves on its distribution manifold. The circulation pump of the floor (or of the building) is switched on by automation whenever any manifold valve on that floor is open, and off again when all valves are closed.
Yes, per manifold: an automation opens the valve when the room temperature drops below the set point and starts the pump once the valve is open (or after a short delay).
The heat pump can be controlled by PIERRE in two ways: • Potential-free contacts: one contact switches winter/summer mode, another starts and stops the heat pump. • Modbus RTU: consult the manufacturer or distributor in advance about the Modbus register addresses and documentation for the heat pump model.
The simplest fan coil units to control are those that can be turned On and Off via relays, with each speed level controlled by separate relays. There are also fan coils that can be controlled using a 0-10V signal, which can also be integrated into the system. Additionally, Modbus communication is possible, but in this case, it is important to consult the manufacturer or supplier in advance regarding the Modbus register addresses and the necessary detailed documentation to ensure the control process is implemented correctly.
The motorized valves for underfloor heating zones can be controlled without any issues by the PIERRE system, whether they are On-Off or 0-10V valves. In the mechanical room, the PIERRE system handles the following controls: winter-summer mode switching via a potential-free contact, circulation pump control, hot water circulation pump control, and 0-10V mixing valve control with supply water temperature measurement.
