HONEYWELL FC-TSRO-0824 Room Temperature Controller

Description

1. Core Overview & Positioning

2. Key Features & Functions

• Embedded Control Sequences:​ Contains pre-programmed, optimized control logic for terminal units, typically implementing a heating/cooling PID algorithm​ with configurable setpoints, deadbands, and operating modes (Heat/Cool/Auto/Off).
• Integrated Temperature Sensing:​ Includes a local input for a temperature sensor​ (e.g., a 10kΩ NTC thermistor or a Honeywell specific sensor) to measure room air temperature. This eliminates the need for a separate sensor in many applications.
• Dedicated Outputs for Terminal Units:​ Features a set of relay outputs designed to directly control the actuators in a fan coil unit or similar device:
  • Fan Speed Control:​ Typically 2 or 3 relays to select fan speeds (High, Medium, Low, Off).
  • Heating/Cooling Valve Control:​ Relays to energize heating valve (normally closed) and cooling valve (normally closed) actuators.
  • Auxiliary Output:​ May include an extra relay for additional control (e.g., a pipe heater, alarm).
• User Interface Integration:​ Designed to connect to a wall-mounted room sensor/thermostat​ (like Honeywell T7350, T7370 series) that provides the user with temperature display, setpoint adjustment, and mode selection. The controller itself is usually installed remotely (e.g., above a ceiling tile near the unit).
• Communication Capability:​ Equipped with a C-Bus communication port​ for integration into a Honeywell Excel 5000 or WEBs BMS network. This allows for:
  • Remote monitoring of space temperature and setpoint.
  • Remote adjustment of setpoints and operating modes.
  • Alarm monitoring (e.g., filter alarm from a connected differential pressure switch).
  • Scheduling and global overrides from the BMS supervisor.
• Standalone Operation:​ Can function independently, with all control logic executed locally based on the connected room sensor.

3. Model Number Breakdown & Specifications

• Power Supply:​ 24V AC or 24V DC​ (standard for HVAC controls).
• Inputs:
  • Room Temperature Input:​ For a 10kΩ NTC thermistor or similar (often via connections for a remote room sensor).
  • Binary Inputs (Optional):​ May include a digital input for a filter alarm switch or an occupancy sensor.
• Outputs:
  • Relay Outputs:​ Typically 5 or 6 SPDT (Form C) relays. Common configuration:
    • 3 relays for Fan Speed (High, Medium, Low).
    • 2 relays for Heating Valve and Cooling Valve.
    • 1 relay for Auxiliary/Alarm.
  • Relay Rating:​ Typically 5A, 240V AC resistive.
• Communication:​ C-Bus port​ for network integration.
• Configuration:​ Configured using Honeywell CARE​ software to set parameters like PID gains, temperature setpoints, fan speed logic, and equipment timers (e.g., fan off delay).
• Mounting:​ DIN-rail mountable enclosure, typically installed in a control cabinet near the terminal unit.

4. System Integration & Wiring

• 1. The controller reads the room temperature from the connected sensor.
  2. Compares it to the active setpoint (from the local user interface or BMS).
  3. Based on the mode (Heat/Cool) and the deviation, it energizes the appropriate valve relay (heating or cooling) to modulate the water flow via the valve actuator.
  4. Simultaneously, it controls the fan speed based on the call for heating/cooling or a user-selected fan speed (Continuous, Intermittent).
• BMS Integration:​ When networked, the BMS can read the room temperature, override the local setpoint for energy savings, and monitor the unit’s status.

5. Typical Applications

• Fan Coil Unit (FCU) Control:​ The most common application, controlling 2-pipe or 4-pipe FCUs in hotel rooms, offices, and apartments.
• Unit Ventilator Control:​ In classrooms and similar spaces.
• Heat Pump Control:​ For water-source or air-source heat pump terminals.
• Radiant System Control:​ Controlling pumps and valves in radiant heating/cooling panels.