Quick Summary
The T6861 series digital thermostat is designed for fan coil systems with 3-speed fan control and 2/4-pipe on/off valve outputs. It also supports functions such as remote setback and remote sensor input, among others.
The following description mainly covers the main functions, specifications, diagrams, display details, and frequently asked questions.
01｜Key Functional Highlights
(1) 3-Speed Fan & 2/4 Pipe Valve Control
Provides precise fan and valve management, ensuring stable airflow and temperature control for diverse FCU configurations.
(2) Remote Setback (Hotel Keycard)
Allows energy-efficient temperature adjustment in unoccupied rooms, reducing operational costs and supporting hotel project standards.
(3) Remote Temperature Sensor
Enables accurate sensing in challenging room layouts, improving system response and maintaining comfort consistency.
02｜Typical Application Scenarios
— Hotel Guest Rooms: Supports room-by-room setback for energy efficiency and guest comfort.
— Office Spaces: Provides reliable fan coil control for varying occupancy and load conditions.
— Residential Apartments: Ensures stable temperature control in multi-zone environments with remote sensing.
03｜System Integration & Control Logic
The thermostat acts as the central control unit in the FCU system, receiving temperature data from built-in or remote sensors. It evaluates the setpoint against the measured temperature and sends on/off commands to the fan and 2/4 pipe valves. Fan speed is adjusted according to system demand, while energy saving and freezing protection modes ensure operational safety. Timer functions allow scheduled operation, reducing unnecessary energy consumption. The control loop maintains room comfort while optimising system efficiency.
【Image 3｜Simple FCU Control Logic Diagram】
04｜Selection Boundary
Suitable for standard FCU applications in hotels, offices, and apartments. Not intended for highly complex BMS or integrated HVAC protocols.
05｜Technical Specifications
| Parameter | Specification |
|---|---|
| Power Supply | 110(+/-10%)VAC, or 220(+10%,-15%)VAC |
| Frequency | 50/60Hz |
| Accuracy | ±1°C at 21°C |
| Rating Capacity | 220V: 4(2)A fan, 2(1)A zone valve |
| Setpoint Range | 10–32°C |
| Display Range | 0–37°C |
| Installation | 86×86 mm junction box or US 2X4 in box |
| Protection Class | IP20 |
| Operating Temperature | -18–49°C |
06｜OEM & Project Customization
Supports batch FCU projects with consistent configuration requirements. Project-specific adjustments, such as colour selection or control logic tweaks, can be discussed to ensure system compatibility. Customisation options are limited to feasible engineering changes without affecting reliability.
07｜Frequently Asked Questions
Q1: Can it control both 2-pipe and 4-pipe FCU systems?
A1: Yes, it supports both 2/4 pipe on/off valve control for fan coil units.
Q2: Is remote temperature sensing possible?
A2: Yes, a remote sensor input allows accurate measurement in diverse room layouts.
Q3: Does it support hotel energy-saving functions?
A3: Yes, remote setback using keycards enables energy-efficient room management.
Q4: What installation options are available?
A4: Can be installed on 86×86 mm junction boxes or US 2X4 in boxes.
08｜Call to Action
Request FCU Thermostat Application Support for your project requirements.
